2 # (C) Copyright 2000 - 2013
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # SPDX-License-Identifier: GPL-2.0+
11 This directory contains the source code for U-Boot, a boot loader for
12 Embedded boards based on PowerPC, ARM, MIPS and several other
13 processors, which can be installed in a boot ROM and used to
14 initialize and test the hardware or to download and run application
17 The development of U-Boot is closely related to Linux: some parts of
18 the source code originate in the Linux source tree, we have some
19 header files in common, and special provision has been made to
20 support booting of Linux images.
22 Some attention has been paid to make this software easily
23 configurable and extendable. For instance, all monitor commands are
24 implemented with the same call interface, so that it's very easy to
25 add new commands. Also, instead of permanently adding rarely used
26 code (for instance hardware test utilities) to the monitor, you can
27 load and run it dynamically.
33 In general, all boards for which a configuration option exists in the
34 Makefile have been tested to some extent and can be considered
35 "working". In fact, many of them are used in production systems.
37 In case of problems see the CHANGELOG file to find out who contributed
38 the specific port. In addition, there are various MAINTAINERS files
39 scattered throughout the U-Boot source identifying the people or
40 companies responsible for various boards and subsystems.
42 Note: As of August, 2010, there is no longer a CHANGELOG file in the
43 actual U-Boot source tree; however, it can be created dynamically
44 from the Git log using:
52 In case you have questions about, problems with or contributions for
53 U-Boot, you should send a message to the U-Boot mailing list at
54 <u-boot@lists.denx.de>. There is also an archive of previous traffic
55 on the mailing list - please search the archive before asking FAQ's.
56 Please see http://lists.denx.de/pipermail/u-boot and
57 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
60 Where to get source code:
61 =========================
63 The U-Boot source code is maintained in the Git repository at
64 git://www.denx.de/git/u-boot.git ; you can browse it online at
65 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
67 The "snapshot" links on this page allow you to download tarballs of
68 any version you might be interested in. Official releases are also
69 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
72 Pre-built (and tested) images are available from
73 ftp://ftp.denx.de/pub/u-boot/images/
79 - start from 8xxrom sources
80 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
82 - make it easier to add custom boards
83 - make it possible to add other [PowerPC] CPUs
84 - extend functions, especially:
85 * Provide extended interface to Linux boot loader
88 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
89 - create ARMBoot project (http://sourceforge.net/projects/armboot)
90 - add other CPU families (starting with ARM)
91 - create U-Boot project (http://sourceforge.net/projects/u-boot)
92 - current project page: see http://www.denx.de/wiki/U-Boot
98 The "official" name of this project is "Das U-Boot". The spelling
99 "U-Boot" shall be used in all written text (documentation, comments
100 in source files etc.). Example:
102 This is the README file for the U-Boot project.
104 File names etc. shall be based on the string "u-boot". Examples:
106 include/asm-ppc/u-boot.h
108 #include <asm/u-boot.h>
110 Variable names, preprocessor constants etc. shall be either based on
111 the string "u_boot" or on "U_BOOT". Example:
113 U_BOOT_VERSION u_boot_logo
114 IH_OS_U_BOOT u_boot_hush_start
120 Starting with the release in October 2008, the names of the releases
121 were changed from numerical release numbers without deeper meaning
122 into a time stamp based numbering. Regular releases are identified by
123 names consisting of the calendar year and month of the release date.
124 Additional fields (if present) indicate release candidates or bug fix
125 releases in "stable" maintenance trees.
128 U-Boot v2009.11 - Release November 2009
129 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
130 U-Boot v2010.09-rc1 - Release candidate 1 for September 2010 release
136 /arch Architecture specific files
137 /arc Files generic to ARC architecture
138 /arm Files generic to ARM architecture
139 /avr32 Files generic to AVR32 architecture
140 /m68k Files generic to m68k architecture
141 /microblaze Files generic to microblaze architecture
142 /mips Files generic to MIPS architecture
143 /nds32 Files generic to NDS32 architecture
144 /nios2 Files generic to Altera NIOS2 architecture
145 /openrisc Files generic to OpenRISC architecture
146 /powerpc Files generic to PowerPC architecture
147 /sandbox Files generic to HW-independent "sandbox"
148 /sh Files generic to SH architecture
149 /x86 Files generic to x86 architecture
150 /api Machine/arch independent API for external apps
151 /board Board dependent files
152 /cmd U-Boot commands functions
153 /common Misc architecture independent functions
154 /configs Board default configuration files
155 /disk Code for disk drive partition handling
156 /doc Documentation (don't expect too much)
157 /drivers Commonly used device drivers
158 /dts Contains Makefile for building internal U-Boot fdt.
159 /examples Example code for standalone applications, etc.
160 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
161 /include Header Files
162 /lib Library routines generic to all architectures
163 /Licenses Various license files
165 /post Power On Self Test
166 /scripts Various build scripts and Makefiles
167 /test Various unit test files
168 /tools Tools to build S-Record or U-Boot images, etc.
170 Software Configuration:
171 =======================
173 Configuration is usually done using C preprocessor defines; the
174 rationale behind that is to avoid dead code whenever possible.
176 There are two classes of configuration variables:
178 * Configuration _OPTIONS_:
179 These are selectable by the user and have names beginning with
182 * Configuration _SETTINGS_:
183 These depend on the hardware etc. and should not be meddled with if
184 you don't know what you're doing; they have names beginning with
187 Previously, all configuration was done by hand, which involved creating
188 symbolic links and editing configuration files manually. More recently,
189 U-Boot has added the Kbuild infrastructure used by the Linux kernel,
190 allowing you to use the "make menuconfig" command to configure your
194 Selection of Processor Architecture and Board Type:
195 ---------------------------------------------------
197 For all supported boards there are ready-to-use default
198 configurations available; just type "make <board_name>_defconfig".
200 Example: For a TQM823L module type:
203 make TQM823L_defconfig
205 Note: If you're looking for the default configuration file for a board
206 you're sure used to be there but is now missing, check the file
207 doc/README.scrapyard for a list of no longer supported boards.
212 U-Boot can be built natively to run on a Linux host using the 'sandbox'
213 board. This allows feature development which is not board- or architecture-
214 specific to be undertaken on a native platform. The sandbox is also used to
215 run some of U-Boot's tests.
217 See board/sandbox/README.sandbox for more details.
220 Board Initialisation Flow:
221 --------------------------
223 This is the intended start-up flow for boards. This should apply for both
224 SPL and U-Boot proper (i.e. they both follow the same rules).
226 Note: "SPL" stands for "Secondary Program Loader," which is explained in
227 more detail later in this file.
229 At present, SPL mostly uses a separate code path, but the function names
230 and roles of each function are the same. Some boards or architectures
231 may not conform to this. At least most ARM boards which use
232 CONFIG_SPL_FRAMEWORK conform to this.
234 Execution typically starts with an architecture-specific (and possibly
235 CPU-specific) start.S file, such as:
237 - arch/arm/cpu/armv7/start.S
238 - arch/powerpc/cpu/mpc83xx/start.S
239 - arch/mips/cpu/start.S
241 and so on. From there, three functions are called; the purpose and
242 limitations of each of these functions are described below.
245 - purpose: essential init to permit execution to reach board_init_f()
246 - no global_data or BSS
247 - there is no stack (ARMv7 may have one but it will soon be removed)
248 - must not set up SDRAM or use console
249 - must only do the bare minimum to allow execution to continue to
251 - this is almost never needed
252 - return normally from this function
255 - purpose: set up the machine ready for running board_init_r():
256 i.e. SDRAM and serial UART
257 - global_data is available
259 - BSS is not available, so you cannot use global/static variables,
260 only stack variables and global_data
262 Non-SPL-specific notes:
263 - dram_init() is called to set up DRAM. If already done in SPL this
267 - you can override the entire board_init_f() function with your own
269 - preloader_console_init() can be called here in extremis
270 - should set up SDRAM, and anything needed to make the UART work
271 - these is no need to clear BSS, it will be done by crt0.S
272 - must return normally from this function (don't call board_init_r()
275 Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
276 this point the stack and global_data are relocated to below
277 CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
281 - purpose: main execution, common code
282 - global_data is available
284 - BSS is available, all static/global variables can be used
285 - execution eventually continues to main_loop()
287 Non-SPL-specific notes:
288 - U-Boot is relocated to the top of memory and is now running from
292 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
293 CONFIG_SPL_STACK_R_ADDR points into SDRAM
294 - preloader_console_init() can be called here - typically this is
295 done by selecting CONFIG_SPL_BOARD_INIT and then supplying a
296 spl_board_init() function containing this call
297 - loads U-Boot or (in falcon mode) Linux
301 Configuration Options:
302 ----------------------
304 Configuration depends on the combination of board and CPU type; all
305 such information is kept in a configuration file
306 "include/configs/<board_name>.h".
308 Example: For a TQM823L module, all configuration settings are in
309 "include/configs/TQM823L.h".
312 Many of the options are named exactly as the corresponding Linux
313 kernel configuration options. The intention is to make it easier to
314 build a config tool - later.
317 The following options need to be configured:
319 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
321 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
323 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
324 Define exactly one, e.g. CONFIG_ATSTK1002
326 - Marvell Family Member
327 CONFIG_SYS_MVFS - define it if you want to enable
328 multiple fs option at one time
329 for marvell soc family
331 - 8xx CPU Options: (if using an MPC8xx CPU)
332 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
333 get_gclk_freq() cannot work
334 e.g. if there is no 32KHz
335 reference PIT/RTC clock
336 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
339 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
340 CONFIG_SYS_8xx_CPUCLK_MIN
341 CONFIG_SYS_8xx_CPUCLK_MAX
342 CONFIG_8xx_CPUCLK_DEFAULT
343 See doc/README.MPC866
345 CONFIG_SYS_MEASURE_CPUCLK
347 Define this to measure the actual CPU clock instead
348 of relying on the correctness of the configured
349 values. Mostly useful for board bringup to make sure
350 the PLL is locked at the intended frequency. Note
351 that this requires a (stable) reference clock (32 kHz
352 RTC clock or CONFIG_SYS_8XX_XIN)
354 CONFIG_SYS_DELAYED_ICACHE
356 Define this option if you want to enable the
357 ICache only when Code runs from RAM.
362 Specifies that the core is a 64-bit PowerPC implementation (implements
363 the "64" category of the Power ISA). This is necessary for ePAPR
364 compliance, among other possible reasons.
366 CONFIG_SYS_FSL_TBCLK_DIV
368 Defines the core time base clock divider ratio compared to the
369 system clock. On most PQ3 devices this is 8, on newer QorIQ
370 devices it can be 16 or 32. The ratio varies from SoC to Soc.
372 CONFIG_SYS_FSL_PCIE_COMPAT
374 Defines the string to utilize when trying to match PCIe device
375 tree nodes for the given platform.
377 CONFIG_SYS_FSL_ERRATUM_A004510
379 Enables a workaround for erratum A004510. If set,
380 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
381 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
383 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
384 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
386 Defines one or two SoC revisions (low 8 bits of SVR)
387 for which the A004510 workaround should be applied.
389 The rest of SVR is either not relevant to the decision
390 of whether the erratum is present (e.g. p2040 versus
391 p2041) or is implied by the build target, which controls
392 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
394 See Freescale App Note 4493 for more information about
397 CONFIG_A003399_NOR_WORKAROUND
398 Enables a workaround for IFC erratum A003399. It is only
399 required during NOR boot.
401 CONFIG_A008044_WORKAROUND
402 Enables a workaround for T1040/T1042 erratum A008044. It is only
403 required during NAND boot and valid for Rev 1.0 SoC revision
405 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
407 This is the value to write into CCSR offset 0x18600
408 according to the A004510 workaround.
410 CONFIG_SYS_FSL_DSP_DDR_ADDR
411 This value denotes start offset of DDR memory which is
412 connected exclusively to the DSP cores.
414 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
415 This value denotes start offset of M2 memory
416 which is directly connected to the DSP core.
418 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
419 This value denotes start offset of M3 memory which is directly
420 connected to the DSP core.
422 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
423 This value denotes start offset of DSP CCSR space.
425 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
426 Single Source Clock is clocking mode present in some of FSL SoC's.
427 In this mode, a single differential clock is used to supply
428 clocks to the sysclock, ddrclock and usbclock.
430 CONFIG_SYS_CPC_REINIT_F
431 This CONFIG is defined when the CPC is configured as SRAM at the
432 time of U-Boot entry and is required to be re-initialized.
435 Indicates this SoC supports deep sleep feature. If deep sleep is
436 supported, core will start to execute uboot when wakes up.
438 - Generic CPU options:
439 CONFIG_SYS_GENERIC_GLOBAL_DATA
440 Defines global data is initialized in generic board board_init_f().
441 If this macro is defined, global data is created and cleared in
442 generic board board_init_f(). Without this macro, architecture/board
443 should initialize global data before calling board_init_f().
445 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
447 Defines the endianess of the CPU. Implementation of those
448 values is arch specific.
451 Freescale DDR driver in use. This type of DDR controller is
452 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
455 CONFIG_SYS_FSL_DDR_ADDR
456 Freescale DDR memory-mapped register base.
458 CONFIG_SYS_FSL_DDR_EMU
459 Specify emulator support for DDR. Some DDR features such as
460 deskew training are not available.
462 CONFIG_SYS_FSL_DDRC_GEN1
463 Freescale DDR1 controller.
465 CONFIG_SYS_FSL_DDRC_GEN2
466 Freescale DDR2 controller.
468 CONFIG_SYS_FSL_DDRC_GEN3
469 Freescale DDR3 controller.
471 CONFIG_SYS_FSL_DDRC_GEN4
472 Freescale DDR4 controller.
474 CONFIG_SYS_FSL_DDRC_ARM_GEN3
475 Freescale DDR3 controller for ARM-based SoCs.
478 Board config to use DDR1. It can be enabled for SoCs with
479 Freescale DDR1 or DDR2 controllers, depending on the board
483 Board config to use DDR2. It can be enabled for SoCs with
484 Freescale DDR2 or DDR3 controllers, depending on the board
488 Board config to use DDR3. It can be enabled for SoCs with
489 Freescale DDR3 or DDR3L controllers.
492 Board config to use DDR3L. It can be enabled for SoCs with
496 Board config to use DDR4. It can be enabled for SoCs with
499 CONFIG_SYS_FSL_IFC_BE
500 Defines the IFC controller register space as Big Endian
502 CONFIG_SYS_FSL_IFC_LE
503 Defines the IFC controller register space as Little Endian
505 CONFIG_SYS_FSL_IFC_CLK_DIV
506 Defines divider of platform clock(clock input to IFC controller).
508 CONFIG_SYS_FSL_LBC_CLK_DIV
509 Defines divider of platform clock(clock input to eLBC controller).
511 CONFIG_SYS_FSL_PBL_PBI
512 It enables addition of RCW (Power on reset configuration) in built image.
513 Please refer doc/README.pblimage for more details
515 CONFIG_SYS_FSL_PBL_RCW
516 It adds PBI(pre-boot instructions) commands in u-boot build image.
517 PBI commands can be used to configure SoC before it starts the execution.
518 Please refer doc/README.pblimage for more details
521 It adds a target to create boot binary having SPL binary in PBI format
522 concatenated with u-boot binary.
524 CONFIG_SYS_FSL_DDR_BE
525 Defines the DDR controller register space as Big Endian
527 CONFIG_SYS_FSL_DDR_LE
528 Defines the DDR controller register space as Little Endian
530 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
531 Physical address from the view of DDR controllers. It is the
532 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
533 it could be different for ARM SoCs.
535 CONFIG_SYS_FSL_DDR_INTLV_256B
536 DDR controller interleaving on 256-byte. This is a special
537 interleaving mode, handled by Dickens for Freescale layerscape
540 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
541 Number of controllers used as main memory.
543 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
544 Number of controllers used for other than main memory.
546 CONFIG_SYS_FSL_HAS_DP_DDR
547 Defines the SoC has DP-DDR used for DPAA.
549 CONFIG_SYS_FSL_SEC_BE
550 Defines the SEC controller register space as Big Endian
552 CONFIG_SYS_FSL_SEC_LE
553 Defines the SEC controller register space as Little Endian
556 CONFIG_SYS_INIT_SP_OFFSET
558 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
559 pointer. This is needed for the temporary stack before
562 CONFIG_SYS_MIPS_CACHE_MODE
564 Cache operation mode for the MIPS CPU.
565 See also arch/mips/include/asm/mipsregs.h.
567 CONF_CM_CACHABLE_NO_WA
570 CONF_CM_CACHABLE_NONCOHERENT
574 CONF_CM_CACHABLE_ACCELERATED
576 CONFIG_SYS_XWAY_EBU_BOOTCFG
578 Special option for Lantiq XWAY SoCs for booting from NOR flash.
579 See also arch/mips/cpu/mips32/start.S.
581 CONFIG_XWAY_SWAP_BYTES
583 Enable compilation of tools/xway-swap-bytes needed for Lantiq
584 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
585 be swapped if a flash programmer is used.
588 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
590 Select high exception vectors of the ARM core, e.g., do not
591 clear the V bit of the c1 register of CP15.
594 Generic timer clock source frequency.
596 COUNTER_FREQUENCY_REAL
597 Generic timer clock source frequency if the real clock is
598 different from COUNTER_FREQUENCY, and can only be determined
602 CONFIG_TEGRA_SUPPORT_NON_SECURE
604 Support executing U-Boot in non-secure (NS) mode. Certain
605 impossible actions will be skipped if the CPU is in NS mode,
606 such as ARM architectural timer initialization.
608 - Linux Kernel Interface:
611 U-Boot stores all clock information in Hz
612 internally. For binary compatibility with older Linux
613 kernels (which expect the clocks passed in the
614 bd_info data to be in MHz) the environment variable
615 "clocks_in_mhz" can be defined so that U-Boot
616 converts clock data to MHZ before passing it to the
618 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
619 "clocks_in_mhz=1" is automatically included in the
622 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
624 When transferring memsize parameter to Linux, some versions
625 expect it to be in bytes, others in MB.
626 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
630 New kernel versions are expecting firmware settings to be
631 passed using flattened device trees (based on open firmware
635 * New libfdt-based support
636 * Adds the "fdt" command
637 * The bootm command automatically updates the fdt
639 OF_CPU - The proper name of the cpus node (only required for
640 MPC512X and MPC5xxx based boards).
641 OF_SOC - The proper name of the soc node (only required for
642 MPC512X and MPC5xxx based boards).
643 OF_TBCLK - The timebase frequency.
644 OF_STDOUT_PATH - The path to the console device
646 boards with QUICC Engines require OF_QE to set UCC MAC
649 CONFIG_OF_BOARD_SETUP
651 Board code has addition modification that it wants to make
652 to the flat device tree before handing it off to the kernel
654 CONFIG_OF_SYSTEM_SETUP
656 Other code has addition modification that it wants to make
657 to the flat device tree before handing it off to the kernel.
658 This causes ft_system_setup() to be called before booting
663 U-Boot can detect if an IDE device is present or not.
664 If not, and this new config option is activated, U-Boot
665 removes the ATA node from the DTS before booting Linux,
666 so the Linux IDE driver does not probe the device and
667 crash. This is needed for buggy hardware (uc101) where
668 no pull down resistor is connected to the signal IDE5V_DD7.
670 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
672 This setting is mandatory for all boards that have only one
673 machine type and must be used to specify the machine type
674 number as it appears in the ARM machine registry
675 (see http://www.arm.linux.org.uk/developer/machines/).
676 Only boards that have multiple machine types supported
677 in a single configuration file and the machine type is
678 runtime discoverable, do not have to use this setting.
680 - vxWorks boot parameters:
682 bootvx constructs a valid bootline using the following
683 environments variables: bootdev, bootfile, ipaddr, netmask,
684 serverip, gatewayip, hostname, othbootargs.
685 It loads the vxWorks image pointed bootfile.
687 Note: If a "bootargs" environment is defined, it will overwride
688 the defaults discussed just above.
690 - Cache Configuration:
691 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
692 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
693 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
695 - Cache Configuration for ARM:
696 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
698 CONFIG_SYS_PL310_BASE - Physical base address of PL310
699 controller register space
704 Define this if you want support for Amba PrimeCell PL010 UARTs.
708 Define this if you want support for Amba PrimeCell PL011 UARTs.
712 If you have Amba PrimeCell PL011 UARTs, set this variable to
713 the clock speed of the UARTs.
717 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
718 define this to a list of base addresses for each (supported)
719 port. See e.g. include/configs/versatile.h
721 CONFIG_SERIAL_HW_FLOW_CONTROL
723 Define this variable to enable hw flow control in serial driver.
724 Current user of this option is drivers/serial/nsl16550.c driver
727 Depending on board, define exactly one serial port
728 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
729 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
730 console by defining CONFIG_8xx_CONS_NONE
732 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
733 port routines must be defined elsewhere
734 (i.e. serial_init(), serial_getc(), ...)
737 CONFIG_BAUDRATE - in bps
738 Select one of the baudrates listed in
739 CONFIG_SYS_BAUDRATE_TABLE, see below.
740 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
742 - Console Rx buffer length
743 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
744 the maximum receive buffer length for the SMC.
745 This option is actual only for 82xx and 8xx possible.
746 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
747 must be defined, to setup the maximum idle timeout for
752 Only needed when CONFIG_BOOTDELAY is enabled;
753 define a command string that is automatically executed
754 when no character is read on the console interface
755 within "Boot Delay" after reset.
758 This can be used to pass arguments to the bootm
759 command. The value of CONFIG_BOOTARGS goes into the
760 environment value "bootargs".
762 CONFIG_RAMBOOT and CONFIG_NFSBOOT
763 The value of these goes into the environment as
764 "ramboot" and "nfsboot" respectively, and can be used
765 as a convenience, when switching between booting from
769 CONFIG_BOOTCOUNT_LIMIT
770 Implements a mechanism for detecting a repeating reboot
772 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
775 If no softreset save registers are found on the hardware
776 "bootcount" is stored in the environment. To prevent a
777 saveenv on all reboots, the environment variable
778 "upgrade_available" is used. If "upgrade_available" is
779 0, "bootcount" is always 0, if "upgrade_available" is
780 1 "bootcount" is incremented in the environment.
781 So the Userspace Applikation must set the "upgrade_available"
782 and "bootcount" variable to 0, if a boot was successfully.
787 When this option is #defined, the existence of the
788 environment variable "preboot" will be checked
789 immediately before starting the CONFIG_BOOTDELAY
790 countdown and/or running the auto-boot command resp.
791 entering interactive mode.
793 This feature is especially useful when "preboot" is
794 automatically generated or modified. For an example
795 see the LWMON board specific code: here "preboot" is
796 modified when the user holds down a certain
797 combination of keys on the (special) keyboard when
800 - Serial Download Echo Mode:
802 If defined to 1, all characters received during a
803 serial download (using the "loads" command) are
804 echoed back. This might be needed by some terminal
805 emulations (like "cu"), but may as well just take
806 time on others. This setting #define's the initial
807 value of the "loads_echo" environment variable.
809 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
811 Select one of the baudrates listed in
812 CONFIG_SYS_BAUDRATE_TABLE, see below.
815 Monitor commands can be included or excluded
816 from the build by using the #include files
817 <config_cmd_all.h> and #undef'ing unwanted
818 commands, or adding #define's for wanted commands.
820 The default command configuration includes all commands
821 except those marked below with a "*".
823 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
824 CONFIG_CMD_ASKENV * ask for env variable
825 CONFIG_CMD_BDI bdinfo
826 CONFIG_CMD_BOOTD bootd
827 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
828 CONFIG_CMD_CACHE * icache, dcache
829 CONFIG_CMD_CONSOLE coninfo
830 CONFIG_CMD_CRC32 * crc32
831 CONFIG_CMD_DHCP * DHCP support
832 CONFIG_CMD_DIAG * Diagnostics
833 CONFIG_CMD_ECHO echo arguments
834 CONFIG_CMD_EDITENV edit env variable
835 CONFIG_CMD_ELF * bootelf, bootvx
836 CONFIG_CMD_ENV_EXISTS * check existence of env variable
837 CONFIG_CMD_EXPORTENV * export the environment
838 CONFIG_CMD_EXT2 * ext2 command support
839 CONFIG_CMD_EXT4 * ext4 command support
840 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
841 that work for multiple fs types
842 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
843 CONFIG_CMD_SAVEENV saveenv
844 CONFIG_CMD_FAT * FAT command support
845 CONFIG_CMD_FLASH flinfo, erase, protect
846 CONFIG_CMD_FPGA FPGA device initialization support
847 CONFIG_CMD_GO * the 'go' command (exec code)
848 CONFIG_CMD_GREPENV * search environment
849 CONFIG_CMD_I2C * I2C serial bus support
850 CONFIG_CMD_IMI iminfo
851 CONFIG_CMD_IMLS List all images found in NOR flash
852 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
853 CONFIG_CMD_IMPORTENV * import an environment
854 CONFIG_CMD_INI * import data from an ini file into the env
855 CONFIG_CMD_IRQ * irqinfo
856 CONFIG_CMD_ITEST Integer/string test of 2 values
857 CONFIG_CMD_KGDB * kgdb
858 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
859 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
861 CONFIG_CMD_LOADB loadb
862 CONFIG_CMD_LOADS loads
863 CONFIG_CMD_MD5SUM * print md5 message digest
864 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
865 CONFIG_CMD_MEMINFO * Display detailed memory information
866 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
868 CONFIG_CMD_MEMTEST * mtest
869 CONFIG_CMD_MISC Misc functions like sleep etc
870 CONFIG_CMD_MMC * MMC memory mapped support
871 CONFIG_CMD_MII * MII utility commands
872 CONFIG_CMD_MTDPARTS * MTD partition support
873 CONFIG_CMD_NAND * NAND support
874 CONFIG_CMD_NET bootp, tftpboot, rarpboot
875 CONFIG_CMD_NFS NFS support
876 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
877 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
878 CONFIG_CMD_PCI * pciinfo
879 CONFIG_CMD_PCMCIA * PCMCIA support
880 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
882 CONFIG_CMD_PORTIO * Port I/O
883 CONFIG_CMD_READ * Read raw data from partition
884 CONFIG_CMD_REGINFO * Register dump
885 CONFIG_CMD_RUN run command in env variable
886 CONFIG_CMD_SANDBOX * sb command to access sandbox features
887 CONFIG_CMD_SAVES * save S record dump
888 CONFIG_SCSI * SCSI Support
889 CONFIG_CMD_SDRAM * print SDRAM configuration information
890 (requires CONFIG_CMD_I2C)
891 CONFIG_CMD_SETGETDCR Support for DCR Register access
893 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
894 CONFIG_CMD_SHA1SUM * print sha1 memory digest
895 (requires CONFIG_CMD_MEMORY)
896 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
897 CONFIG_CMD_SOURCE "source" command Support
898 CONFIG_CMD_SPI * SPI serial bus support
899 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
900 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
901 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
902 CONFIG_CMD_TIMER * access to the system tick timer
903 CONFIG_CMD_USB * USB support
904 CONFIG_CMD_CDP * Cisco Discover Protocol support
905 CONFIG_CMD_MFSL * Microblaze FSL support
906 CONFIG_CMD_XIMG Load part of Multi Image
907 CONFIG_CMD_UUID * Generate random UUID or GUID string
909 EXAMPLE: If you want all functions except of network
910 support you can write:
912 #include "config_cmd_all.h"
913 #undef CONFIG_CMD_NET
916 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
918 Note: Don't enable the "icache" and "dcache" commands
919 (configuration option CONFIG_CMD_CACHE) unless you know
920 what you (and your U-Boot users) are doing. Data
921 cache cannot be enabled on systems like the 8xx or
922 8260 (where accesses to the IMMR region must be
923 uncached), and it cannot be disabled on all other
924 systems where we (mis-) use the data cache to hold an
925 initial stack and some data.
928 XXX - this list needs to get updated!
930 - Removal of commands
931 If no commands are needed to boot, you can disable
932 CONFIG_CMDLINE to remove them. In this case, the command line
933 will not be available, and when U-Boot wants to execute the
934 boot command (on start-up) it will call board_run_command()
935 instead. This can reduce image size significantly for very
936 simple boot procedures.
938 - Regular expression support:
940 If this variable is defined, U-Boot is linked against
941 the SLRE (Super Light Regular Expression) library,
942 which adds regex support to some commands, as for
943 example "env grep" and "setexpr".
947 If this variable is defined, U-Boot will use a device tree
948 to configure its devices, instead of relying on statically
949 compiled #defines in the board file. This option is
950 experimental and only available on a few boards. The device
951 tree is available in the global data as gd->fdt_blob.
953 U-Boot needs to get its device tree from somewhere. This can
954 be done using one of the three options below:
957 If this variable is defined, U-Boot will embed a device tree
958 binary in its image. This device tree file should be in the
959 board directory and called <soc>-<board>.dts. The binary file
960 is then picked up in board_init_f() and made available through
961 the global data structure as gd->blob.
964 If this variable is defined, U-Boot will build a device tree
965 binary. It will be called u-boot.dtb. Architecture-specific
966 code will locate it at run-time. Generally this works by:
968 cat u-boot.bin u-boot.dtb >image.bin
970 and in fact, U-Boot does this for you, creating a file called
971 u-boot-dtb.bin which is useful in the common case. You can
972 still use the individual files if you need something more
976 If this variable is defined, U-Boot will use the device tree
977 provided by the board at runtime instead of embedding one with
978 the image. Only boards defining board_fdt_blob_setup() support
979 this option (see include/fdtdec.h file).
983 If this variable is defined, it enables watchdog
984 support for the SoC. There must be support in the SoC
985 specific code for a watchdog. For the 8xx and 8260
986 CPUs, the SIU Watchdog feature is enabled in the SYPCR
987 register. When supported for a specific SoC is
988 available, then no further board specific code should
992 When using a watchdog circuitry external to the used
993 SoC, then define this variable and provide board
994 specific code for the "hw_watchdog_reset" function.
996 CONFIG_AT91_HW_WDT_TIMEOUT
997 specify the timeout in seconds. default 2 seconds.
1000 CONFIG_VERSION_VARIABLE
1001 If this variable is defined, an environment variable
1002 named "ver" is created by U-Boot showing the U-Boot
1003 version as printed by the "version" command.
1004 Any change to this variable will be reverted at the
1009 When CONFIG_CMD_DATE is selected, the type of the RTC
1010 has to be selected, too. Define exactly one of the
1013 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1014 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1015 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1016 CONFIG_RTC_MC146818 - use MC146818 RTC
1017 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1018 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1019 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1020 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1021 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1022 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1023 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1024 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1025 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1028 Note that if the RTC uses I2C, then the I2C interface
1029 must also be configured. See I2C Support, below.
1032 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1034 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1035 chip-ngpio pairs that tell the PCA953X driver the number of
1036 pins supported by a particular chip.
1038 Note that if the GPIO device uses I2C, then the I2C interface
1039 must also be configured. See I2C Support, below.
1042 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1043 accesses and can checksum them or write a list of them out
1044 to memory. See the 'iotrace' command for details. This is
1045 useful for testing device drivers since it can confirm that
1046 the driver behaves the same way before and after a code
1047 change. Currently this is supported on sandbox and arm. To
1048 add support for your architecture, add '#include <iotrace.h>'
1049 to the bottom of arch/<arch>/include/asm/io.h and test.
1051 Example output from the 'iotrace stats' command is below.
1052 Note that if the trace buffer is exhausted, the checksum will
1053 still continue to operate.
1056 Start: 10000000 (buffer start address)
1057 Size: 00010000 (buffer size)
1058 Offset: 00000120 (current buffer offset)
1059 Output: 10000120 (start + offset)
1060 Count: 00000018 (number of trace records)
1061 CRC32: 9526fb66 (CRC32 of all trace records)
1063 - Timestamp Support:
1065 When CONFIG_TIMESTAMP is selected, the timestamp
1066 (date and time) of an image is printed by image
1067 commands like bootm or iminfo. This option is
1068 automatically enabled when you select CONFIG_CMD_DATE .
1070 - Partition Labels (disklabels) Supported:
1071 Zero or more of the following:
1072 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1073 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1074 Intel architecture, USB sticks, etc.
1075 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1076 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1077 bootloader. Note 2TB partition limit; see
1079 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1081 If IDE or SCSI support is enabled (CONFIG_IDE or
1082 CONFIG_SCSI) you must configure support for at
1083 least one non-MTD partition type as well.
1086 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1087 board configurations files but used nowhere!
1089 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1090 be performed by calling the function
1091 ide_set_reset(int reset)
1092 which has to be defined in a board specific file
1097 Set this to enable ATAPI support.
1102 Set this to enable support for disks larger than 137GB
1103 Also look at CONFIG_SYS_64BIT_LBA.
1104 Whithout these , LBA48 support uses 32bit variables and will 'only'
1105 support disks up to 2.1TB.
1107 CONFIG_SYS_64BIT_LBA:
1108 When enabled, makes the IDE subsystem use 64bit sector addresses.
1112 At the moment only there is only support for the
1113 SYM53C8XX SCSI controller; define
1114 CONFIG_SCSI_SYM53C8XX to enable it.
1116 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1117 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1118 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1119 maximum numbers of LUNs, SCSI ID's and target
1121 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1123 The environment variable 'scsidevs' is set to the number of
1124 SCSI devices found during the last scan.
1126 - NETWORK Support (PCI):
1128 Support for Intel 8254x/8257x gigabit chips.
1131 Utility code for direct access to the SPI bus on Intel 8257x.
1132 This does not do anything useful unless you set at least one
1133 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1135 CONFIG_E1000_SPI_GENERIC
1136 Allow generic access to the SPI bus on the Intel 8257x, for
1137 example with the "sspi" command.
1140 Management command for E1000 devices. When used on devices
1141 with SPI support you can reprogram the EEPROM from U-Boot.
1144 Support for Intel 82557/82559/82559ER chips.
1145 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1146 write routine for first time initialisation.
1149 Support for Digital 2114x chips.
1150 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1151 modem chip initialisation (KS8761/QS6611).
1154 Support for National dp83815 chips.
1157 Support for National dp8382[01] gigabit chips.
1159 - NETWORK Support (other):
1161 CONFIG_DRIVER_AT91EMAC
1162 Support for AT91RM9200 EMAC.
1165 Define this to use reduced MII inteface
1167 CONFIG_DRIVER_AT91EMAC_QUIET
1168 If this defined, the driver is quiet.
1169 The driver doen't show link status messages.
1171 CONFIG_CALXEDA_XGMAC
1172 Support for the Calxeda XGMAC device
1175 Support for SMSC's LAN91C96 chips.
1177 CONFIG_LAN91C96_USE_32_BIT
1178 Define this to enable 32 bit addressing
1181 Support for SMSC's LAN91C111 chip
1183 CONFIG_SMC91111_BASE
1184 Define this to hold the physical address
1185 of the device (I/O space)
1187 CONFIG_SMC_USE_32_BIT
1188 Define this if data bus is 32 bits
1190 CONFIG_SMC_USE_IOFUNCS
1191 Define this to use i/o functions instead of macros
1192 (some hardware wont work with macros)
1194 CONFIG_DRIVER_TI_EMAC
1195 Support for davinci emac
1197 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1198 Define this if you have more then 3 PHYs.
1201 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1203 CONFIG_FTGMAC100_EGIGA
1204 Define this to use GE link update with gigabit PHY.
1205 Define this if FTGMAC100 is connected to gigabit PHY.
1206 If your system has 10/100 PHY only, it might not occur
1207 wrong behavior. Because PHY usually return timeout or
1208 useless data when polling gigabit status and gigabit
1209 control registers. This behavior won't affect the
1210 correctnessof 10/100 link speed update.
1213 Support for SMSC's LAN911x and LAN921x chips
1216 Define this to hold the physical address
1217 of the device (I/O space)
1219 CONFIG_SMC911X_32_BIT
1220 Define this if data bus is 32 bits
1222 CONFIG_SMC911X_16_BIT
1223 Define this if data bus is 16 bits. If your processor
1224 automatically converts one 32 bit word to two 16 bit
1225 words you may also try CONFIG_SMC911X_32_BIT.
1228 Support for Renesas on-chip Ethernet controller
1230 CONFIG_SH_ETHER_USE_PORT
1231 Define the number of ports to be used
1233 CONFIG_SH_ETHER_PHY_ADDR
1234 Define the ETH PHY's address
1236 CONFIG_SH_ETHER_CACHE_WRITEBACK
1237 If this option is set, the driver enables cache flush.
1241 Support for PWM module on the imx6.
1245 Support TPM devices.
1247 CONFIG_TPM_TIS_INFINEON
1248 Support for Infineon i2c bus TPM devices. Only one device
1249 per system is supported at this time.
1251 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1252 Define the burst count bytes upper limit
1255 Support for STMicroelectronics TPM devices. Requires DM_TPM support.
1257 CONFIG_TPM_ST33ZP24_I2C
1258 Support for STMicroelectronics ST33ZP24 I2C devices.
1259 Requires TPM_ST33ZP24 and I2C.
1261 CONFIG_TPM_ST33ZP24_SPI
1262 Support for STMicroelectronics ST33ZP24 SPI devices.
1263 Requires TPM_ST33ZP24 and SPI.
1265 CONFIG_TPM_ATMEL_TWI
1266 Support for Atmel TWI TPM device. Requires I2C support.
1269 Support for generic parallel port TPM devices. Only one device
1270 per system is supported at this time.
1272 CONFIG_TPM_TIS_BASE_ADDRESS
1273 Base address where the generic TPM device is mapped
1274 to. Contemporary x86 systems usually map it at
1278 Add tpm monitor functions.
1279 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1280 provides monitor access to authorized functions.
1283 Define this to enable the TPM support library which provides
1284 functional interfaces to some TPM commands.
1285 Requires support for a TPM device.
1287 CONFIG_TPM_AUTH_SESSIONS
1288 Define this to enable authorized functions in the TPM library.
1289 Requires CONFIG_TPM and CONFIG_SHA1.
1292 At the moment only the UHCI host controller is
1293 supported (PIP405, MIP405, MPC5200); define
1294 CONFIG_USB_UHCI to enable it.
1295 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1296 and define CONFIG_USB_STORAGE to enable the USB
1299 Supported are USB Keyboards and USB Floppy drives
1301 MPC5200 USB requires additional defines:
1303 for 528 MHz Clock: 0x0001bbbb
1307 for differential drivers: 0x00001000
1308 for single ended drivers: 0x00005000
1309 for differential drivers on PSC3: 0x00000100
1310 for single ended drivers on PSC3: 0x00004100
1311 CONFIG_SYS_USB_EVENT_POLL
1312 May be defined to allow interrupt polling
1313 instead of using asynchronous interrupts
1315 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1316 txfilltuning field in the EHCI controller on reset.
1318 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1319 HW module registers.
1322 Define the below if you wish to use the USB console.
1323 Once firmware is rebuilt from a serial console issue the
1324 command "setenv stdin usbtty; setenv stdout usbtty" and
1325 attach your USB cable. The Unix command "dmesg" should print
1326 it has found a new device. The environment variable usbtty
1327 can be set to gserial or cdc_acm to enable your device to
1328 appear to a USB host as a Linux gserial device or a
1329 Common Device Class Abstract Control Model serial device.
1330 If you select usbtty = gserial you should be able to enumerate
1332 # modprobe usbserial vendor=0xVendorID product=0xProductID
1333 else if using cdc_acm, simply setting the environment
1334 variable usbtty to be cdc_acm should suffice. The following
1335 might be defined in YourBoardName.h
1338 Define this to build a UDC device
1341 Define this to have a tty type of device available to
1342 talk to the UDC device
1345 Define this to enable the high speed support for usb
1346 device and usbtty. If this feature is enabled, a routine
1347 int is_usbd_high_speed(void)
1348 also needs to be defined by the driver to dynamically poll
1349 whether the enumeration has succeded at high speed or full
1352 CONFIG_SYS_CONSOLE_IS_IN_ENV
1353 Define this if you want stdin, stdout &/or stderr to
1357 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1358 Derive USB clock from external clock "blah"
1359 - CONFIG_SYS_USB_EXTC_CLK 0x02
1361 If you have a USB-IF assigned VendorID then you may wish to
1362 define your own vendor specific values either in BoardName.h
1363 or directly in usbd_vendor_info.h. If you don't define
1364 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1365 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1366 should pretend to be a Linux device to it's target host.
1368 CONFIG_USBD_MANUFACTURER
1369 Define this string as the name of your company for
1370 - CONFIG_USBD_MANUFACTURER "my company"
1372 CONFIG_USBD_PRODUCT_NAME
1373 Define this string as the name of your product
1374 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1376 CONFIG_USBD_VENDORID
1377 Define this as your assigned Vendor ID from the USB
1378 Implementors Forum. This *must* be a genuine Vendor ID
1379 to avoid polluting the USB namespace.
1380 - CONFIG_USBD_VENDORID 0xFFFF
1382 CONFIG_USBD_PRODUCTID
1383 Define this as the unique Product ID
1385 - CONFIG_USBD_PRODUCTID 0xFFFF
1387 - ULPI Layer Support:
1388 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1389 the generic ULPI layer. The generic layer accesses the ULPI PHY
1390 via the platform viewport, so you need both the genric layer and
1391 the viewport enabled. Currently only Chipidea/ARC based
1392 viewport is supported.
1393 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1394 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1395 If your ULPI phy needs a different reference clock than the
1396 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1397 the appropriate value in Hz.
1400 The MMC controller on the Intel PXA is supported. To
1401 enable this define CONFIG_MMC. The MMC can be
1402 accessed from the boot prompt by mapping the device
1403 to physical memory similar to flash. Command line is
1404 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1405 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1408 Support for Renesas on-chip MMCIF controller
1410 CONFIG_SH_MMCIF_ADDR
1411 Define the base address of MMCIF registers
1414 Define the clock frequency for MMCIF
1416 CONFIG_SUPPORT_EMMC_BOOT
1417 Enable some additional features of the eMMC boot partitions.
1419 CONFIG_SUPPORT_EMMC_RPMB
1420 Enable the commands for reading, writing and programming the
1421 key for the Replay Protection Memory Block partition in eMMC.
1423 - USB Device Firmware Update (DFU) class support:
1424 CONFIG_USB_FUNCTION_DFU
1425 This enables the USB portion of the DFU USB class
1428 This enables the command "dfu" which is used to have
1429 U-Boot create a DFU class device via USB. This command
1430 requires that the "dfu_alt_info" environment variable be
1431 set and define the alt settings to expose to the host.
1434 This enables support for exposing (e)MMC devices via DFU.
1437 This enables support for exposing NAND devices via DFU.
1440 This enables support for exposing RAM via DFU.
1441 Note: DFU spec refer to non-volatile memory usage, but
1442 allow usages beyond the scope of spec - here RAM usage,
1443 one that would help mostly the developer.
1445 CONFIG_SYS_DFU_DATA_BUF_SIZE
1446 Dfu transfer uses a buffer before writing data to the
1447 raw storage device. Make the size (in bytes) of this buffer
1448 configurable. The size of this buffer is also configurable
1449 through the "dfu_bufsiz" environment variable.
1451 CONFIG_SYS_DFU_MAX_FILE_SIZE
1452 When updating files rather than the raw storage device,
1453 we use a static buffer to copy the file into and then write
1454 the buffer once we've been given the whole file. Define
1455 this to the maximum filesize (in bytes) for the buffer.
1456 Default is 4 MiB if undefined.
1458 DFU_DEFAULT_POLL_TIMEOUT
1459 Poll timeout [ms], is the timeout a device can send to the
1460 host. The host must wait for this timeout before sending
1461 a subsequent DFU_GET_STATUS request to the device.
1463 DFU_MANIFEST_POLL_TIMEOUT
1464 Poll timeout [ms], which the device sends to the host when
1465 entering dfuMANIFEST state. Host waits this timeout, before
1466 sending again an USB request to the device.
1468 - USB Device Android Fastboot support:
1469 CONFIG_USB_FUNCTION_FASTBOOT
1470 This enables the USB part of the fastboot gadget
1473 This enables the command "fastboot" which enables the Android
1474 fastboot mode for the platform's USB device. Fastboot is a USB
1475 protocol for downloading images, flashing and device control
1476 used on Android devices.
1477 See doc/README.android-fastboot for more information.
1479 CONFIG_ANDROID_BOOT_IMAGE
1480 This enables support for booting images which use the Android
1481 image format header.
1483 CONFIG_FASTBOOT_BUF_ADDR
1484 The fastboot protocol requires a large memory buffer for
1485 downloads. Define this to the starting RAM address to use for
1488 CONFIG_FASTBOOT_BUF_SIZE
1489 The fastboot protocol requires a large memory buffer for
1490 downloads. This buffer should be as large as possible for a
1491 platform. Define this to the size available RAM for fastboot.
1493 CONFIG_FASTBOOT_FLASH
1494 The fastboot protocol includes a "flash" command for writing
1495 the downloaded image to a non-volatile storage device. Define
1496 this to enable the "fastboot flash" command.
1498 CONFIG_FASTBOOT_FLASH_MMC_DEV
1499 The fastboot "flash" command requires additional information
1500 regarding the non-volatile storage device. Define this to
1501 the eMMC device that fastboot should use to store the image.
1503 CONFIG_FASTBOOT_GPT_NAME
1504 The fastboot "flash" command supports writing the downloaded
1505 image to the Protective MBR and the Primary GUID Partition
1506 Table. (Additionally, this downloaded image is post-processed
1507 to generate and write the Backup GUID Partition Table.)
1508 This occurs when the specified "partition name" on the
1509 "fastboot flash" command line matches this value.
1510 The default is "gpt" if undefined.
1512 CONFIG_FASTBOOT_MBR_NAME
1513 The fastboot "flash" command supports writing the downloaded
1515 This occurs when the "partition name" specified on the
1516 "fastboot flash" command line matches this value.
1517 If not defined the default value "mbr" is used.
1519 - Journaling Flash filesystem support:
1521 Define these for a default partition on a NAND device
1523 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1524 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1525 Define these for a default partition on a NOR device
1527 - FAT(File Allocation Table) filesystem write function support:
1530 Define this to enable support for saving memory data as a
1531 file in FAT formatted partition.
1533 This will also enable the command "fatwrite" enabling the
1534 user to write files to FAT.
1536 - FAT(File Allocation Table) filesystem cluster size:
1537 CONFIG_FS_FAT_MAX_CLUSTSIZE
1539 Define the max cluster size for fat operations else
1540 a default value of 65536 will be defined.
1543 See Kconfig help for available keyboard drivers.
1547 Define this to enable a custom keyboard support.
1548 This simply calls drv_keyboard_init() which must be
1549 defined in your board-specific files. This option is deprecated
1550 and is only used by novena. For new boards, use driver model
1555 Enable the Freescale DIU video driver. Reference boards for
1556 SOCs that have a DIU should define this macro to enable DIU
1557 support, and should also define these other macros:
1562 CONFIG_VIDEO_SW_CURSOR
1563 CONFIG_VGA_AS_SINGLE_DEVICE
1565 CONFIG_VIDEO_BMP_LOGO
1567 The DIU driver will look for the 'video-mode' environment
1568 variable, and if defined, enable the DIU as a console during
1569 boot. See the documentation file doc/README.video for a
1570 description of this variable.
1572 - LCD Support: CONFIG_LCD
1574 Define this to enable LCD support (for output to LCD
1575 display); also select one of the supported displays
1576 by defining one of these:
1580 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1582 CONFIG_NEC_NL6448AC33:
1584 NEC NL6448AC33-18. Active, color, single scan.
1586 CONFIG_NEC_NL6448BC20
1588 NEC NL6448BC20-08. 6.5", 640x480.
1589 Active, color, single scan.
1591 CONFIG_NEC_NL6448BC33_54
1593 NEC NL6448BC33-54. 10.4", 640x480.
1594 Active, color, single scan.
1598 Sharp 320x240. Active, color, single scan.
1599 It isn't 16x9, and I am not sure what it is.
1601 CONFIG_SHARP_LQ64D341
1603 Sharp LQ64D341 display, 640x480.
1604 Active, color, single scan.
1608 HLD1045 display, 640x480.
1609 Active, color, single scan.
1613 Optrex CBL50840-2 NF-FW 99 22 M5
1615 Hitachi LMG6912RPFC-00T
1619 320x240. Black & white.
1621 CONFIG_LCD_ALIGNMENT
1623 Normally the LCD is page-aligned (typically 4KB). If this is
1624 defined then the LCD will be aligned to this value instead.
1625 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1626 here, since it is cheaper to change data cache settings on
1627 a per-section basis.
1632 Sometimes, for example if the display is mounted in portrait
1633 mode or even if it's mounted landscape but rotated by 180degree,
1634 we need to rotate our content of the display relative to the
1635 framebuffer, so that user can read the messages which are
1637 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1638 initialized with a given rotation from "vl_rot" out of
1639 "vidinfo_t" which is provided by the board specific code.
1640 The value for vl_rot is coded as following (matching to
1641 fbcon=rotate:<n> linux-kernel commandline):
1642 0 = no rotation respectively 0 degree
1643 1 = 90 degree rotation
1644 2 = 180 degree rotation
1645 3 = 270 degree rotation
1647 If CONFIG_LCD_ROTATION is not defined, the console will be
1648 initialized with 0degree rotation.
1652 Support drawing of RLE8-compressed bitmaps on the LCD.
1656 Enables an 'i2c edid' command which can read EDID
1657 information over I2C from an attached LCD display.
1659 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1661 If this option is set, the environment is checked for
1662 a variable "splashimage". If found, the usual display
1663 of logo, copyright and system information on the LCD
1664 is suppressed and the BMP image at the address
1665 specified in "splashimage" is loaded instead. The
1666 console is redirected to the "nulldev", too. This
1667 allows for a "silent" boot where a splash screen is
1668 loaded very quickly after power-on.
1670 CONFIG_SPLASHIMAGE_GUARD
1672 If this option is set, then U-Boot will prevent the environment
1673 variable "splashimage" from being set to a problematic address
1674 (see doc/README.displaying-bmps).
1675 This option is useful for targets where, due to alignment
1676 restrictions, an improperly aligned BMP image will cause a data
1677 abort. If you think you will not have problems with unaligned
1678 accesses (for example because your toolchain prevents them)
1679 there is no need to set this option.
1681 CONFIG_SPLASH_SCREEN_ALIGN
1683 If this option is set the splash image can be freely positioned
1684 on the screen. Environment variable "splashpos" specifies the
1685 position as "x,y". If a positive number is given it is used as
1686 number of pixel from left/top. If a negative number is given it
1687 is used as number of pixel from right/bottom. You can also
1688 specify 'm' for centering the image.
1691 setenv splashpos m,m
1692 => image at center of screen
1694 setenv splashpos 30,20
1695 => image at x = 30 and y = 20
1697 setenv splashpos -10,m
1698 => vertically centered image
1699 at x = dspWidth - bmpWidth - 9
1701 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1703 If this option is set, additionally to standard BMP
1704 images, gzipped BMP images can be displayed via the
1705 splashscreen support or the bmp command.
1707 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1709 If this option is set, 8-bit RLE compressed BMP images
1710 can be displayed via the splashscreen support or the
1713 - Compression support:
1716 Enabled by default to support gzip compressed images.
1720 If this option is set, support for bzip2 compressed
1721 images is included. If not, only uncompressed and gzip
1722 compressed images are supported.
1724 NOTE: the bzip2 algorithm requires a lot of RAM, so
1725 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1730 If this option is set, support for lzma compressed
1733 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1734 requires an amount of dynamic memory that is given by the
1737 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1739 Where lc and lp stand for, respectively, Literal context bits
1740 and Literal pos bits.
1742 This value is upper-bounded by 14MB in the worst case. Anyway,
1743 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1744 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1745 a very small buffer.
1747 Use the lzmainfo tool to determinate the lc and lp values and
1748 then calculate the amount of needed dynamic memory (ensuring
1749 the appropriate CONFIG_SYS_MALLOC_LEN value).
1753 If this option is set, support for LZO compressed images
1759 The address of PHY on MII bus.
1761 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1763 The clock frequency of the MII bus
1767 If this option is set, support for speed/duplex
1768 detection of gigabit PHY is included.
1770 CONFIG_PHY_RESET_DELAY
1772 Some PHY like Intel LXT971A need extra delay after
1773 reset before any MII register access is possible.
1774 For such PHY, set this option to the usec delay
1775 required. (minimum 300usec for LXT971A)
1777 CONFIG_PHY_CMD_DELAY (ppc4xx)
1779 Some PHY like Intel LXT971A need extra delay after
1780 command issued before MII status register can be read
1785 Define a default value for the IP address to use for
1786 the default Ethernet interface, in case this is not
1787 determined through e.g. bootp.
1788 (Environment variable "ipaddr")
1790 - Server IP address:
1793 Defines a default value for the IP address of a TFTP
1794 server to contact when using the "tftboot" command.
1795 (Environment variable "serverip")
1797 CONFIG_KEEP_SERVERADDR
1799 Keeps the server's MAC address, in the env 'serveraddr'
1800 for passing to bootargs (like Linux's netconsole option)
1802 - Gateway IP address:
1805 Defines a default value for the IP address of the
1806 default router where packets to other networks are
1808 (Environment variable "gatewayip")
1813 Defines a default value for the subnet mask (or
1814 routing prefix) which is used to determine if an IP
1815 address belongs to the local subnet or needs to be
1816 forwarded through a router.
1817 (Environment variable "netmask")
1819 - Multicast TFTP Mode:
1822 Defines whether you want to support multicast TFTP as per
1823 rfc-2090; for example to work with atftp. Lets lots of targets
1824 tftp down the same boot image concurrently. Note: the Ethernet
1825 driver in use must provide a function: mcast() to join/leave a
1828 - BOOTP Recovery Mode:
1829 CONFIG_BOOTP_RANDOM_DELAY
1831 If you have many targets in a network that try to
1832 boot using BOOTP, you may want to avoid that all
1833 systems send out BOOTP requests at precisely the same
1834 moment (which would happen for instance at recovery
1835 from a power failure, when all systems will try to
1836 boot, thus flooding the BOOTP server. Defining
1837 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1838 inserted before sending out BOOTP requests. The
1839 following delays are inserted then:
1841 1st BOOTP request: delay 0 ... 1 sec
1842 2nd BOOTP request: delay 0 ... 2 sec
1843 3rd BOOTP request: delay 0 ... 4 sec
1845 BOOTP requests: delay 0 ... 8 sec
1847 CONFIG_BOOTP_ID_CACHE_SIZE
1849 BOOTP packets are uniquely identified using a 32-bit ID. The
1850 server will copy the ID from client requests to responses and
1851 U-Boot will use this to determine if it is the destination of
1852 an incoming response. Some servers will check that addresses
1853 aren't in use before handing them out (usually using an ARP
1854 ping) and therefore take up to a few hundred milliseconds to
1855 respond. Network congestion may also influence the time it
1856 takes for a response to make it back to the client. If that
1857 time is too long, U-Boot will retransmit requests. In order
1858 to allow earlier responses to still be accepted after these
1859 retransmissions, U-Boot's BOOTP client keeps a small cache of
1860 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
1861 cache. The default is to keep IDs for up to four outstanding
1862 requests. Increasing this will allow U-Boot to accept offers
1863 from a BOOTP client in networks with unusually high latency.
1865 - DHCP Advanced Options:
1866 You can fine tune the DHCP functionality by defining
1867 CONFIG_BOOTP_* symbols:
1869 CONFIG_BOOTP_SUBNETMASK
1870 CONFIG_BOOTP_GATEWAY
1871 CONFIG_BOOTP_HOSTNAME
1872 CONFIG_BOOTP_NISDOMAIN
1873 CONFIG_BOOTP_BOOTPATH
1874 CONFIG_BOOTP_BOOTFILESIZE
1877 CONFIG_BOOTP_SEND_HOSTNAME
1878 CONFIG_BOOTP_NTPSERVER
1879 CONFIG_BOOTP_TIMEOFFSET
1880 CONFIG_BOOTP_VENDOREX
1881 CONFIG_BOOTP_MAY_FAIL
1883 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1884 environment variable, not the BOOTP server.
1886 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1887 after the configured retry count, the call will fail
1888 instead of starting over. This can be used to fail over
1889 to Link-local IP address configuration if the DHCP server
1892 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1893 serverip from a DHCP server, it is possible that more
1894 than one DNS serverip is offered to the client.
1895 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1896 serverip will be stored in the additional environment
1897 variable "dnsip2". The first DNS serverip is always
1898 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1901 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1902 to do a dynamic update of a DNS server. To do this, they
1903 need the hostname of the DHCP requester.
1904 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1905 of the "hostname" environment variable is passed as
1906 option 12 to the DHCP server.
1908 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1910 A 32bit value in microseconds for a delay between
1911 receiving a "DHCP Offer" and sending the "DHCP Request".
1912 This fixes a problem with certain DHCP servers that don't
1913 respond 100% of the time to a "DHCP request". E.g. On an
1914 AT91RM9200 processor running at 180MHz, this delay needed
1915 to be *at least* 15,000 usec before a Windows Server 2003
1916 DHCP server would reply 100% of the time. I recommend at
1917 least 50,000 usec to be safe. The alternative is to hope
1918 that one of the retries will be successful but note that
1919 the DHCP timeout and retry process takes a longer than
1922 - Link-local IP address negotiation:
1923 Negotiate with other link-local clients on the local network
1924 for an address that doesn't require explicit configuration.
1925 This is especially useful if a DHCP server cannot be guaranteed
1926 to exist in all environments that the device must operate.
1928 See doc/README.link-local for more information.
1931 CONFIG_CDP_DEVICE_ID
1933 The device id used in CDP trigger frames.
1935 CONFIG_CDP_DEVICE_ID_PREFIX
1937 A two character string which is prefixed to the MAC address
1942 A printf format string which contains the ascii name of
1943 the port. Normally is set to "eth%d" which sets
1944 eth0 for the first Ethernet, eth1 for the second etc.
1946 CONFIG_CDP_CAPABILITIES
1948 A 32bit integer which indicates the device capabilities;
1949 0x00000010 for a normal host which does not forwards.
1953 An ascii string containing the version of the software.
1957 An ascii string containing the name of the platform.
1961 A 32bit integer sent on the trigger.
1963 CONFIG_CDP_POWER_CONSUMPTION
1965 A 16bit integer containing the power consumption of the
1966 device in .1 of milliwatts.
1968 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1970 A byte containing the id of the VLAN.
1972 - Status LED: CONFIG_LED_STATUS
1974 Several configurations allow to display the current
1975 status using a LED. For instance, the LED will blink
1976 fast while running U-Boot code, stop blinking as
1977 soon as a reply to a BOOTP request was received, and
1978 start blinking slow once the Linux kernel is running
1979 (supported by a status LED driver in the Linux
1980 kernel). Defining CONFIG_LED_STATUS enables this
1985 CONFIG_LED_STATUS_GPIO
1986 The status LED can be connected to a GPIO pin.
1987 In such cases, the gpio_led driver can be used as a
1988 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO
1989 to include the gpio_led driver in the U-Boot binary.
1991 CONFIG_GPIO_LED_INVERTED_TABLE
1992 Some GPIO connected LEDs may have inverted polarity in which
1993 case the GPIO high value corresponds to LED off state and
1994 GPIO low value corresponds to LED on state.
1995 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
1996 with a list of GPIO LEDs that have inverted polarity.
1998 - CAN Support: CONFIG_CAN_DRIVER
2000 Defining CONFIG_CAN_DRIVER enables CAN driver support
2001 on those systems that support this (optional)
2002 feature, like the TQM8xxL modules.
2004 - I2C Support: CONFIG_SYS_I2C
2006 This enable the NEW i2c subsystem, and will allow you to use
2007 i2c commands at the u-boot command line (as long as you set
2008 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2009 based realtime clock chips or other i2c devices. See
2010 common/cmd_i2c.c for a description of the command line
2013 ported i2c driver to the new framework:
2014 - drivers/i2c/soft_i2c.c:
2015 - activate first bus with CONFIG_SYS_I2C_SOFT define
2016 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2017 for defining speed and slave address
2018 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2019 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2020 for defining speed and slave address
2021 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2022 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2023 for defining speed and slave address
2024 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2025 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2026 for defining speed and slave address
2028 - drivers/i2c/fsl_i2c.c:
2029 - activate i2c driver with CONFIG_SYS_I2C_FSL
2030 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2031 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2032 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2034 - If your board supports a second fsl i2c bus, define
2035 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2036 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2037 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2040 - drivers/i2c/tegra_i2c.c:
2041 - activate this driver with CONFIG_SYS_I2C_TEGRA
2042 - This driver adds 4 i2c buses with a fix speed from
2043 100000 and the slave addr 0!
2045 - drivers/i2c/ppc4xx_i2c.c
2046 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2047 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2048 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2050 - drivers/i2c/i2c_mxc.c
2051 - activate this driver with CONFIG_SYS_I2C_MXC
2052 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1
2053 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2
2054 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
2055 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
2056 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2057 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2058 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2059 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2060 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2061 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2062 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED
2063 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE
2064 If those defines are not set, default value is 100000
2065 for speed, and 0 for slave.
2067 - drivers/i2c/rcar_i2c.c:
2068 - activate this driver with CONFIG_SYS_I2C_RCAR
2069 - This driver adds 4 i2c buses
2071 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2072 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2073 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2074 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2075 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2076 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2077 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2078 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2079 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2081 - drivers/i2c/sh_i2c.c:
2082 - activate this driver with CONFIG_SYS_I2C_SH
2083 - This driver adds from 2 to 5 i2c buses
2085 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2086 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2087 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2088 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2089 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2090 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2091 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2092 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2093 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2094 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2095 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2097 - drivers/i2c/omap24xx_i2c.c
2098 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2099 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2100 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2101 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2102 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2103 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2104 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2105 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2106 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2107 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2108 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2110 - drivers/i2c/zynq_i2c.c
2111 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2112 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2113 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2115 - drivers/i2c/s3c24x0_i2c.c:
2116 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2117 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2118 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2119 with a fix speed from 100000 and the slave addr 0!
2121 - drivers/i2c/ihs_i2c.c
2122 - activate this driver with CONFIG_SYS_I2C_IHS
2123 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2124 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2125 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2126 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2127 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2128 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2129 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2130 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2131 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2132 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2133 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2134 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2135 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL
2136 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1
2137 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1
2138 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1
2139 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1
2140 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1
2141 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1
2142 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1
2143 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1
2147 CONFIG_SYS_NUM_I2C_BUSES
2148 Hold the number of i2c buses you want to use.
2150 CONFIG_SYS_I2C_DIRECT_BUS
2151 define this, if you don't use i2c muxes on your hardware.
2152 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2155 CONFIG_SYS_I2C_MAX_HOPS
2156 define how many muxes are maximal consecutively connected
2157 on one i2c bus. If you not use i2c muxes, omit this
2160 CONFIG_SYS_I2C_BUSES
2161 hold a list of buses you want to use, only used if
2162 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2163 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2164 CONFIG_SYS_NUM_I2C_BUSES = 9:
2166 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2167 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2168 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2169 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2170 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2171 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2172 {1, {I2C_NULL_HOP}}, \
2173 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2174 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2178 bus 0 on adapter 0 without a mux
2179 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2180 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2181 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2182 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2183 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2184 bus 6 on adapter 1 without a mux
2185 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2186 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2188 If you do not have i2c muxes on your board, omit this define.
2190 - Legacy I2C Support:
2191 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2192 then the following macros need to be defined (examples are
2193 from include/configs/lwmon.h):
2197 (Optional). Any commands necessary to enable the I2C
2198 controller or configure ports.
2200 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2204 (Only for MPC8260 CPU). The I/O port to use (the code
2205 assumes both bits are on the same port). Valid values
2206 are 0..3 for ports A..D.
2210 The code necessary to make the I2C data line active
2211 (driven). If the data line is open collector, this
2214 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2218 The code necessary to make the I2C data line tri-stated
2219 (inactive). If the data line is open collector, this
2222 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2226 Code that returns true if the I2C data line is high,
2229 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2233 If <bit> is true, sets the I2C data line high. If it
2234 is false, it clears it (low).
2236 eg: #define I2C_SDA(bit) \
2237 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2238 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2242 If <bit> is true, sets the I2C clock line high. If it
2243 is false, it clears it (low).
2245 eg: #define I2C_SCL(bit) \
2246 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2247 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2251 This delay is invoked four times per clock cycle so this
2252 controls the rate of data transfer. The data rate thus
2253 is 1 / (I2C_DELAY * 4). Often defined to be something
2256 #define I2C_DELAY udelay(2)
2258 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2260 If your arch supports the generic GPIO framework (asm/gpio.h),
2261 then you may alternatively define the two GPIOs that are to be
2262 used as SCL / SDA. Any of the previous I2C_xxx macros will
2263 have GPIO-based defaults assigned to them as appropriate.
2265 You should define these to the GPIO value as given directly to
2266 the generic GPIO functions.
2268 CONFIG_SYS_I2C_INIT_BOARD
2270 When a board is reset during an i2c bus transfer
2271 chips might think that the current transfer is still
2272 in progress. On some boards it is possible to access
2273 the i2c SCLK line directly, either by using the
2274 processor pin as a GPIO or by having a second pin
2275 connected to the bus. If this option is defined a
2276 custom i2c_init_board() routine in boards/xxx/board.c
2277 is run early in the boot sequence.
2279 CONFIG_I2C_MULTI_BUS
2281 This option allows the use of multiple I2C buses, each of which
2282 must have a controller. At any point in time, only one bus is
2283 active. To switch to a different bus, use the 'i2c dev' command.
2284 Note that bus numbering is zero-based.
2286 CONFIG_SYS_I2C_NOPROBES
2288 This option specifies a list of I2C devices that will be skipped
2289 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2290 is set, specify a list of bus-device pairs. Otherwise, specify
2291 a 1D array of device addresses
2294 #undef CONFIG_I2C_MULTI_BUS
2295 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2297 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2299 #define CONFIG_I2C_MULTI_BUS
2300 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2302 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2304 CONFIG_SYS_SPD_BUS_NUM
2306 If defined, then this indicates the I2C bus number for DDR SPD.
2307 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2309 CONFIG_SYS_RTC_BUS_NUM
2311 If defined, then this indicates the I2C bus number for the RTC.
2312 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2314 CONFIG_SOFT_I2C_READ_REPEATED_START
2316 defining this will force the i2c_read() function in
2317 the soft_i2c driver to perform an I2C repeated start
2318 between writing the address pointer and reading the
2319 data. If this define is omitted the default behaviour
2320 of doing a stop-start sequence will be used. Most I2C
2321 devices can use either method, but some require one or
2324 - SPI Support: CONFIG_SPI
2326 Enables SPI driver (so far only tested with
2327 SPI EEPROM, also an instance works with Crystal A/D and
2328 D/As on the SACSng board)
2332 Enables the driver for SPI controller on SuperH. Currently
2333 only SH7757 is supported.
2337 Enables a software (bit-bang) SPI driver rather than
2338 using hardware support. This is a general purpose
2339 driver that only requires three general I/O port pins
2340 (two outputs, one input) to function. If this is
2341 defined, the board configuration must define several
2342 SPI configuration items (port pins to use, etc). For
2343 an example, see include/configs/sacsng.h.
2347 Enables a hardware SPI driver for general-purpose reads
2348 and writes. As with CONFIG_SOFT_SPI, the board configuration
2349 must define a list of chip-select function pointers.
2350 Currently supported on some MPC8xxx processors. For an
2351 example, see include/configs/mpc8349emds.h.
2355 Enables the driver for the SPI controllers on i.MX and MXC
2356 SoCs. Currently i.MX31/35/51 are supported.
2358 CONFIG_SYS_SPI_MXC_WAIT
2359 Timeout for waiting until spi transfer completed.
2360 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2362 - FPGA Support: CONFIG_FPGA
2364 Enables FPGA subsystem.
2366 CONFIG_FPGA_<vendor>
2368 Enables support for specific chip vendors.
2371 CONFIG_FPGA_<family>
2373 Enables support for FPGA family.
2374 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2378 Specify the number of FPGA devices to support.
2380 CONFIG_SYS_FPGA_PROG_FEEDBACK
2382 Enable printing of hash marks during FPGA configuration.
2384 CONFIG_SYS_FPGA_CHECK_BUSY
2386 Enable checks on FPGA configuration interface busy
2387 status by the configuration function. This option
2388 will require a board or device specific function to
2393 If defined, a function that provides delays in the FPGA
2394 configuration driver.
2396 CONFIG_SYS_FPGA_CHECK_CTRLC
2397 Allow Control-C to interrupt FPGA configuration
2399 CONFIG_SYS_FPGA_CHECK_ERROR
2401 Check for configuration errors during FPGA bitfile
2402 loading. For example, abort during Virtex II
2403 configuration if the INIT_B line goes low (which
2404 indicated a CRC error).
2406 CONFIG_SYS_FPGA_WAIT_INIT
2408 Maximum time to wait for the INIT_B line to de-assert
2409 after PROB_B has been de-asserted during a Virtex II
2410 FPGA configuration sequence. The default time is 500
2413 CONFIG_SYS_FPGA_WAIT_BUSY
2415 Maximum time to wait for BUSY to de-assert during
2416 Virtex II FPGA configuration. The default is 5 ms.
2418 CONFIG_SYS_FPGA_WAIT_CONFIG
2420 Time to wait after FPGA configuration. The default is
2423 - Configuration Management:
2426 Some SoCs need special image types (e.g. U-Boot binary
2427 with a special header) as build targets. By defining
2428 CONFIG_BUILD_TARGET in the SoC / board header, this
2429 special image will be automatically built upon calling
2434 If defined, this string will be added to the U-Boot
2435 version information (U_BOOT_VERSION)
2437 - Vendor Parameter Protection:
2439 U-Boot considers the values of the environment
2440 variables "serial#" (Board Serial Number) and
2441 "ethaddr" (Ethernet Address) to be parameters that
2442 are set once by the board vendor / manufacturer, and
2443 protects these variables from casual modification by
2444 the user. Once set, these variables are read-only,
2445 and write or delete attempts are rejected. You can
2446 change this behaviour:
2448 If CONFIG_ENV_OVERWRITE is #defined in your config
2449 file, the write protection for vendor parameters is
2450 completely disabled. Anybody can change or delete
2453 Alternatively, if you define _both_ an ethaddr in the
2454 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2455 Ethernet address is installed in the environment,
2456 which can be changed exactly ONCE by the user. [The
2457 serial# is unaffected by this, i. e. it remains
2460 The same can be accomplished in a more flexible way
2461 for any variable by configuring the type of access
2462 to allow for those variables in the ".flags" variable
2463 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2468 Define this variable to enable the reservation of
2469 "protected RAM", i. e. RAM which is not overwritten
2470 by U-Boot. Define CONFIG_PRAM to hold the number of
2471 kB you want to reserve for pRAM. You can overwrite
2472 this default value by defining an environment
2473 variable "pram" to the number of kB you want to
2474 reserve. Note that the board info structure will
2475 still show the full amount of RAM. If pRAM is
2476 reserved, a new environment variable "mem" will
2477 automatically be defined to hold the amount of
2478 remaining RAM in a form that can be passed as boot
2479 argument to Linux, for instance like that:
2481 setenv bootargs ... mem=\${mem}
2484 This way you can tell Linux not to use this memory,
2485 either, which results in a memory region that will
2486 not be affected by reboots.
2488 *WARNING* If your board configuration uses automatic
2489 detection of the RAM size, you must make sure that
2490 this memory test is non-destructive. So far, the
2491 following board configurations are known to be
2494 IVMS8, IVML24, SPD8xx, TQM8xxL,
2495 HERMES, IP860, RPXlite, LWMON,
2498 - Access to physical memory region (> 4GB)
2499 Some basic support is provided for operations on memory not
2500 normally accessible to U-Boot - e.g. some architectures
2501 support access to more than 4GB of memory on 32-bit
2502 machines using physical address extension or similar.
2503 Define CONFIG_PHYSMEM to access this basic support, which
2504 currently only supports clearing the memory.
2509 Define this variable to stop the system in case of a
2510 fatal error, so that you have to reset it manually.
2511 This is probably NOT a good idea for an embedded
2512 system where you want the system to reboot
2513 automatically as fast as possible, but it may be
2514 useful during development since you can try to debug
2515 the conditions that lead to the situation.
2517 CONFIG_NET_RETRY_COUNT
2519 This variable defines the number of retries for
2520 network operations like ARP, RARP, TFTP, or BOOTP
2521 before giving up the operation. If not defined, a
2522 default value of 5 is used.
2526 Timeout waiting for an ARP reply in milliseconds.
2530 Timeout in milliseconds used in NFS protocol.
2531 If you encounter "ERROR: Cannot umount" in nfs command,
2532 try longer timeout such as
2533 #define CONFIG_NFS_TIMEOUT 10000UL
2535 - Command Interpreter:
2536 CONFIG_AUTO_COMPLETE
2538 Enable auto completion of commands using TAB.
2540 CONFIG_SYS_PROMPT_HUSH_PS2
2542 This defines the secondary prompt string, which is
2543 printed when the command interpreter needs more input
2544 to complete a command. Usually "> ".
2548 In the current implementation, the local variables
2549 space and global environment variables space are
2550 separated. Local variables are those you define by
2551 simply typing `name=value'. To access a local
2552 variable later on, you have write `$name' or
2553 `${name}'; to execute the contents of a variable
2554 directly type `$name' at the command prompt.
2556 Global environment variables are those you use
2557 setenv/printenv to work with. To run a command stored
2558 in such a variable, you need to use the run command,
2559 and you must not use the '$' sign to access them.
2561 To store commands and special characters in a
2562 variable, please use double quotation marks
2563 surrounding the whole text of the variable, instead
2564 of the backslashes before semicolons and special
2567 - Command Line Editing and History:
2568 CONFIG_CMDLINE_EDITING
2570 Enable editing and History functions for interactive
2571 command line input operations
2573 - Command Line PS1/PS2 support:
2574 CONFIG_CMDLINE_PS_SUPPORT
2576 Enable support for changing the command prompt string
2577 at run-time. Only static string is supported so far.
2578 The string is obtained from environment variables PS1
2581 - Default Environment:
2582 CONFIG_EXTRA_ENV_SETTINGS
2584 Define this to contain any number of null terminated
2585 strings (variable = value pairs) that will be part of
2586 the default environment compiled into the boot image.
2588 For example, place something like this in your
2589 board's config file:
2591 #define CONFIG_EXTRA_ENV_SETTINGS \
2595 Warning: This method is based on knowledge about the
2596 internal format how the environment is stored by the
2597 U-Boot code. This is NOT an official, exported
2598 interface! Although it is unlikely that this format
2599 will change soon, there is no guarantee either.
2600 You better know what you are doing here.
2602 Note: overly (ab)use of the default environment is
2603 discouraged. Make sure to check other ways to preset
2604 the environment like the "source" command or the
2607 CONFIG_ENV_VARS_UBOOT_CONFIG
2609 Define this in order to add variables describing the
2610 U-Boot build configuration to the default environment.
2611 These will be named arch, cpu, board, vendor, and soc.
2613 Enabling this option will cause the following to be defined:
2621 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2623 Define this in order to add variables describing certain
2624 run-time determined information about the hardware to the
2625 environment. These will be named board_name, board_rev.
2627 CONFIG_DELAY_ENVIRONMENT
2629 Normally the environment is loaded when the board is
2630 initialised so that it is available to U-Boot. This inhibits
2631 that so that the environment is not available until
2632 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2633 this is instead controlled by the value of
2634 /config/load-environment.
2636 - DataFlash Support:
2637 CONFIG_HAS_DATAFLASH
2639 Defining this option enables DataFlash features and
2640 allows to read/write in Dataflash via the standard
2643 - Serial Flash support
2646 Defining this option enables SPI flash commands
2647 'sf probe/read/write/erase/update'.
2649 Usage requires an initial 'probe' to define the serial
2650 flash parameters, followed by read/write/erase/update
2653 The following defaults may be provided by the platform
2654 to handle the common case when only a single serial
2655 flash is present on the system.
2657 CONFIG_SF_DEFAULT_BUS Bus identifier
2658 CONFIG_SF_DEFAULT_CS Chip-select
2659 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2660 CONFIG_SF_DEFAULT_SPEED in Hz
2664 Define this option to include a destructive SPI flash
2667 CONFIG_SF_DUAL_FLASH Dual flash memories
2669 Define this option to use dual flash support where two flash
2670 memories can be connected with a given cs line.
2671 Currently Xilinx Zynq qspi supports these type of connections.
2673 - SystemACE Support:
2676 Adding this option adds support for Xilinx SystemACE
2677 chips attached via some sort of local bus. The address
2678 of the chip must also be defined in the
2679 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2681 #define CONFIG_SYSTEMACE
2682 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2684 When SystemACE support is added, the "ace" device type
2685 becomes available to the fat commands, i.e. fatls.
2687 - TFTP Fixed UDP Port:
2690 If this is defined, the environment variable tftpsrcp
2691 is used to supply the TFTP UDP source port value.
2692 If tftpsrcp isn't defined, the normal pseudo-random port
2693 number generator is used.
2695 Also, the environment variable tftpdstp is used to supply
2696 the TFTP UDP destination port value. If tftpdstp isn't
2697 defined, the normal port 69 is used.
2699 The purpose for tftpsrcp is to allow a TFTP server to
2700 blindly start the TFTP transfer using the pre-configured
2701 target IP address and UDP port. This has the effect of
2702 "punching through" the (Windows XP) firewall, allowing
2703 the remainder of the TFTP transfer to proceed normally.
2704 A better solution is to properly configure the firewall,
2705 but sometimes that is not allowed.
2710 Enable the hash verify command (hash -v). This adds to code
2713 Note: There is also a sha1sum command, which should perhaps
2714 be deprecated in favour of 'hash sha1'.
2716 - bootcount support:
2717 CONFIG_BOOTCOUNT_LIMIT
2719 This enables the bootcounter support, see:
2720 http://www.denx.de/wiki/DULG/UBootBootCountLimit
2723 enable special bootcounter support on at91sam9xe based boards.
2725 enable special bootcounter support on da850 based boards.
2726 CONFIG_BOOTCOUNT_RAM
2727 enable support for the bootcounter in RAM
2728 CONFIG_BOOTCOUNT_I2C
2729 enable support for the bootcounter on an i2c (like RTC) device.
2730 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
2731 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
2733 CONFIG_BOOTCOUNT_ALEN = address len
2735 - Show boot progress:
2736 CONFIG_SHOW_BOOT_PROGRESS
2738 Defining this option allows to add some board-
2739 specific code (calling a user-provided function
2740 "show_boot_progress(int)") that enables you to show
2741 the system's boot progress on some display (for
2742 example, some LED's) on your board. At the moment,
2743 the following checkpoints are implemented:
2746 Legacy uImage format:
2749 1 common/cmd_bootm.c before attempting to boot an image
2750 -1 common/cmd_bootm.c Image header has bad magic number
2751 2 common/cmd_bootm.c Image header has correct magic number
2752 -2 common/cmd_bootm.c Image header has bad checksum
2753 3 common/cmd_bootm.c Image header has correct checksum
2754 -3 common/cmd_bootm.c Image data has bad checksum
2755 4 common/cmd_bootm.c Image data has correct checksum
2756 -4 common/cmd_bootm.c Image is for unsupported architecture
2757 5 common/cmd_bootm.c Architecture check OK
2758 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2759 6 common/cmd_bootm.c Image Type check OK
2760 -6 common/cmd_bootm.c gunzip uncompression error
2761 -7 common/cmd_bootm.c Unimplemented compression type
2762 7 common/cmd_bootm.c Uncompression OK
2763 8 common/cmd_bootm.c No uncompress/copy overwrite error
2764 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2766 9 common/image.c Start initial ramdisk verification
2767 -10 common/image.c Ramdisk header has bad magic number
2768 -11 common/image.c Ramdisk header has bad checksum
2769 10 common/image.c Ramdisk header is OK
2770 -12 common/image.c Ramdisk data has bad checksum
2771 11 common/image.c Ramdisk data has correct checksum
2772 12 common/image.c Ramdisk verification complete, start loading
2773 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2774 13 common/image.c Start multifile image verification
2775 14 common/image.c No initial ramdisk, no multifile, continue.
2777 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2779 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2780 -31 post/post.c POST test failed, detected by post_output_backlog()
2781 -32 post/post.c POST test failed, detected by post_run_single()
2783 34 common/cmd_doc.c before loading a Image from a DOC device
2784 -35 common/cmd_doc.c Bad usage of "doc" command
2785 35 common/cmd_doc.c correct usage of "doc" command
2786 -36 common/cmd_doc.c No boot device
2787 36 common/cmd_doc.c correct boot device
2788 -37 common/cmd_doc.c Unknown Chip ID on boot device
2789 37 common/cmd_doc.c correct chip ID found, device available
2790 -38 common/cmd_doc.c Read Error on boot device
2791 38 common/cmd_doc.c reading Image header from DOC device OK
2792 -39 common/cmd_doc.c Image header has bad magic number
2793 39 common/cmd_doc.c Image header has correct magic number
2794 -40 common/cmd_doc.c Error reading Image from DOC device
2795 40 common/cmd_doc.c Image header has correct magic number
2796 41 common/cmd_ide.c before loading a Image from a IDE device
2797 -42 common/cmd_ide.c Bad usage of "ide" command
2798 42 common/cmd_ide.c correct usage of "ide" command
2799 -43 common/cmd_ide.c No boot device
2800 43 common/cmd_ide.c boot device found
2801 -44 common/cmd_ide.c Device not available
2802 44 common/cmd_ide.c Device available
2803 -45 common/cmd_ide.c wrong partition selected
2804 45 common/cmd_ide.c partition selected
2805 -46 common/cmd_ide.c Unknown partition table
2806 46 common/cmd_ide.c valid partition table found
2807 -47 common/cmd_ide.c Invalid partition type
2808 47 common/cmd_ide.c correct partition type
2809 -48 common/cmd_ide.c Error reading Image Header on boot device
2810 48 common/cmd_ide.c reading Image Header from IDE device OK
2811 -49 common/cmd_ide.c Image header has bad magic number
2812 49 common/cmd_ide.c Image header has correct magic number
2813 -50 common/cmd_ide.c Image header has bad checksum
2814 50 common/cmd_ide.c Image header has correct checksum
2815 -51 common/cmd_ide.c Error reading Image from IDE device
2816 51 common/cmd_ide.c reading Image from IDE device OK
2817 52 common/cmd_nand.c before loading a Image from a NAND device
2818 -53 common/cmd_nand.c Bad usage of "nand" command
2819 53 common/cmd_nand.c correct usage of "nand" command
2820 -54 common/cmd_nand.c No boot device
2821 54 common/cmd_nand.c boot device found
2822 -55 common/cmd_nand.c Unknown Chip ID on boot device
2823 55 common/cmd_nand.c correct chip ID found, device available
2824 -56 common/cmd_nand.c Error reading Image Header on boot device
2825 56 common/cmd_nand.c reading Image Header from NAND device OK
2826 -57 common/cmd_nand.c Image header has bad magic number
2827 57 common/cmd_nand.c Image header has correct magic number
2828 -58 common/cmd_nand.c Error reading Image from NAND device
2829 58 common/cmd_nand.c reading Image from NAND device OK
2831 -60 common/env_common.c Environment has a bad CRC, using default
2833 64 net/eth.c starting with Ethernet configuration.
2834 -64 net/eth.c no Ethernet found.
2835 65 net/eth.c Ethernet found.
2837 -80 common/cmd_net.c usage wrong
2838 80 common/cmd_net.c before calling net_loop()
2839 -81 common/cmd_net.c some error in net_loop() occurred
2840 81 common/cmd_net.c net_loop() back without error
2841 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2842 82 common/cmd_net.c trying automatic boot
2843 83 common/cmd_net.c running "source" command
2844 -83 common/cmd_net.c some error in automatic boot or "source" command
2845 84 common/cmd_net.c end without errors
2850 100 common/cmd_bootm.c Kernel FIT Image has correct format
2851 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2852 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2853 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2854 102 common/cmd_bootm.c Kernel unit name specified
2855 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2856 103 common/cmd_bootm.c Found configuration node
2857 104 common/cmd_bootm.c Got kernel subimage node offset
2858 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2859 105 common/cmd_bootm.c Kernel subimage hash verification OK
2860 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2861 106 common/cmd_bootm.c Architecture check OK
2862 -106 common/cmd_bootm.c Kernel subimage has wrong type
2863 107 common/cmd_bootm.c Kernel subimage type OK
2864 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2865 108 common/cmd_bootm.c Got kernel subimage data/size
2866 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2867 -109 common/cmd_bootm.c Can't get kernel subimage type
2868 -110 common/cmd_bootm.c Can't get kernel subimage comp
2869 -111 common/cmd_bootm.c Can't get kernel subimage os
2870 -112 common/cmd_bootm.c Can't get kernel subimage load address
2871 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2873 120 common/image.c Start initial ramdisk verification
2874 -120 common/image.c Ramdisk FIT image has incorrect format
2875 121 common/image.c Ramdisk FIT image has correct format
2876 122 common/image.c No ramdisk subimage unit name, using configuration
2877 -122 common/image.c Can't get configuration for ramdisk subimage
2878 123 common/image.c Ramdisk unit name specified
2879 -124 common/image.c Can't get ramdisk subimage node offset
2880 125 common/image.c Got ramdisk subimage node offset
2881 -125 common/image.c Ramdisk subimage hash verification failed
2882 126 common/image.c Ramdisk subimage hash verification OK
2883 -126 common/image.c Ramdisk subimage for unsupported architecture
2884 127 common/image.c Architecture check OK
2885 -127 common/image.c Can't get ramdisk subimage data/size
2886 128 common/image.c Got ramdisk subimage data/size
2887 129 common/image.c Can't get ramdisk load address
2888 -129 common/image.c Got ramdisk load address
2890 -130 common/cmd_doc.c Incorrect FIT image format
2891 131 common/cmd_doc.c FIT image format OK
2893 -140 common/cmd_ide.c Incorrect FIT image format
2894 141 common/cmd_ide.c FIT image format OK
2896 -150 common/cmd_nand.c Incorrect FIT image format
2897 151 common/cmd_nand.c FIT image format OK
2899 - legacy image format:
2900 CONFIG_IMAGE_FORMAT_LEGACY
2901 enables the legacy image format support in U-Boot.
2904 enabled if CONFIG_FIT_SIGNATURE is not defined.
2906 CONFIG_DISABLE_IMAGE_LEGACY
2907 disable the legacy image format
2909 This define is introduced, as the legacy image format is
2910 enabled per default for backward compatibility.
2912 - Standalone program support:
2913 CONFIG_STANDALONE_LOAD_ADDR
2915 This option defines a board specific value for the
2916 address where standalone program gets loaded, thus
2917 overwriting the architecture dependent default
2920 - Frame Buffer Address:
2923 Define CONFIG_FB_ADDR if you want to use specific
2924 address for frame buffer. This is typically the case
2925 when using a graphics controller has separate video
2926 memory. U-Boot will then place the frame buffer at
2927 the given address instead of dynamically reserving it
2928 in system RAM by calling lcd_setmem(), which grabs
2929 the memory for the frame buffer depending on the
2930 configured panel size.
2932 Please see board_init_f function.
2934 - Automatic software updates via TFTP server
2936 CONFIG_UPDATE_TFTP_CNT_MAX
2937 CONFIG_UPDATE_TFTP_MSEC_MAX
2939 These options enable and control the auto-update feature;
2940 for a more detailed description refer to doc/README.update.
2942 - MTD Support (mtdparts command, UBI support)
2945 Adds the MTD device infrastructure from the Linux kernel.
2946 Needed for mtdparts command support.
2948 CONFIG_MTD_PARTITIONS
2950 Adds the MTD partitioning infrastructure from the Linux
2951 kernel. Needed for UBI support.
2956 Adds commands for interacting with MTD partitions formatted
2957 with the UBI flash translation layer
2959 Requires also defining CONFIG_RBTREE
2961 CONFIG_UBI_SILENCE_MSG
2963 Make the verbose messages from UBI stop printing. This leaves
2964 warnings and errors enabled.
2967 CONFIG_MTD_UBI_WL_THRESHOLD
2968 This parameter defines the maximum difference between the highest
2969 erase counter value and the lowest erase counter value of eraseblocks
2970 of UBI devices. When this threshold is exceeded, UBI starts performing
2971 wear leveling by means of moving data from eraseblock with low erase
2972 counter to eraseblocks with high erase counter.
2974 The default value should be OK for SLC NAND flashes, NOR flashes and
2975 other flashes which have eraseblock life-cycle 100000 or more.
2976 However, in case of MLC NAND flashes which typically have eraseblock
2977 life-cycle less than 10000, the threshold should be lessened (e.g.,
2978 to 128 or 256, although it does not have to be power of 2).
2982 CONFIG_MTD_UBI_BEB_LIMIT
2983 This option specifies the maximum bad physical eraseblocks UBI
2984 expects on the MTD device (per 1024 eraseblocks). If the
2985 underlying flash does not admit of bad eraseblocks (e.g. NOR
2986 flash), this value is ignored.
2988 NAND datasheets often specify the minimum and maximum NVM
2989 (Number of Valid Blocks) for the flashes' endurance lifetime.
2990 The maximum expected bad eraseblocks per 1024 eraseblocks
2991 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
2992 which gives 20 for most NANDs (MaxNVB is basically the total
2993 count of eraseblocks on the chip).
2995 To put it differently, if this value is 20, UBI will try to
2996 reserve about 1.9% of physical eraseblocks for bad blocks
2997 handling. And that will be 1.9% of eraseblocks on the entire
2998 NAND chip, not just the MTD partition UBI attaches. This means
2999 that if you have, say, a NAND flash chip admits maximum 40 bad
3000 eraseblocks, and it is split on two MTD partitions of the same
3001 size, UBI will reserve 40 eraseblocks when attaching a
3006 CONFIG_MTD_UBI_FASTMAP
3007 Fastmap is a mechanism which allows attaching an UBI device
3008 in nearly constant time. Instead of scanning the whole MTD device it
3009 only has to locate a checkpoint (called fastmap) on the device.
3010 The on-flash fastmap contains all information needed to attach
3011 the device. Using fastmap makes only sense on large devices where
3012 attaching by scanning takes long. UBI will not automatically install
3013 a fastmap on old images, but you can set the UBI parameter
3014 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3015 that fastmap-enabled images are still usable with UBI implementations
3016 without fastmap support. On typical flash devices the whole fastmap
3017 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3019 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3020 Set this parameter to enable fastmap automatically on images
3024 CONFIG_MTD_UBI_FM_DEBUG
3025 Enable UBI fastmap debug
3031 Adds commands for interacting with UBI volumes formatted as
3032 UBIFS. UBIFS is read-only in u-boot.
3034 Requires UBI support as well as CONFIG_LZO
3036 CONFIG_UBIFS_SILENCE_MSG
3038 Make the verbose messages from UBIFS stop printing. This leaves
3039 warnings and errors enabled.
3043 Enable building of SPL globally.
3046 LDSCRIPT for linking the SPL binary.
3048 CONFIG_SPL_MAX_FOOTPRINT
3049 Maximum size in memory allocated to the SPL, BSS included.
3050 When defined, the linker checks that the actual memory
3051 used by SPL from _start to __bss_end does not exceed it.
3052 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3053 must not be both defined at the same time.
3056 Maximum size of the SPL image (text, data, rodata, and
3057 linker lists sections), BSS excluded.
3058 When defined, the linker checks that the actual size does
3061 CONFIG_SPL_TEXT_BASE
3062 TEXT_BASE for linking the SPL binary.
3064 CONFIG_SPL_RELOC_TEXT_BASE
3065 Address to relocate to. If unspecified, this is equal to
3066 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3068 CONFIG_SPL_BSS_START_ADDR
3069 Link address for the BSS within the SPL binary.
3071 CONFIG_SPL_BSS_MAX_SIZE
3072 Maximum size in memory allocated to the SPL BSS.
3073 When defined, the linker checks that the actual memory used
3074 by SPL from __bss_start to __bss_end does not exceed it.
3075 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3076 must not be both defined at the same time.
3079 Adress of the start of the stack SPL will use
3081 CONFIG_SPL_PANIC_ON_RAW_IMAGE
3082 When defined, SPL will panic() if the image it has
3083 loaded does not have a signature.
3084 Defining this is useful when code which loads images
3085 in SPL cannot guarantee that absolutely all read errors
3087 An example is the LPC32XX MLC NAND driver, which will
3088 consider that a completely unreadable NAND block is bad,
3089 and thus should be skipped silently.
3091 CONFIG_SPL_RELOC_STACK
3092 Adress of the start of the stack SPL will use after
3093 relocation. If unspecified, this is equal to
3096 CONFIG_SYS_SPL_MALLOC_START
3097 Starting address of the malloc pool used in SPL.
3098 When this option is set the full malloc is used in SPL and
3099 it is set up by spl_init() and before that, the simple malloc()
3100 can be used if CONFIG_SYS_MALLOC_F is defined.
3102 CONFIG_SYS_SPL_MALLOC_SIZE
3103 The size of the malloc pool used in SPL.
3105 CONFIG_SPL_FRAMEWORK
3106 Enable the SPL framework under common/. This framework
3107 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3108 NAND loading of the Linux Kernel.
3111 Enable booting directly to an OS from SPL.
3112 See also: doc/README.falcon
3114 CONFIG_SPL_DISPLAY_PRINT
3115 For ARM, enable an optional function to print more information
3116 about the running system.
3118 CONFIG_SPL_INIT_MINIMAL
3119 Arch init code should be built for a very small image
3121 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3122 Partition on the MMC to load U-Boot from when the MMC is being
3125 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3126 Sector to load kernel uImage from when MMC is being
3127 used in raw mode (for Falcon mode)
3129 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3130 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3131 Sector and number of sectors to load kernel argument
3132 parameters from when MMC is being used in raw mode
3135 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3136 Partition on the MMC to load U-Boot from when the MMC is being
3139 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3140 Filename to read to load U-Boot when reading from filesystem
3142 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3143 Filename to read to load kernel uImage when reading
3144 from filesystem (for Falcon mode)
3146 CONFIG_SPL_FS_LOAD_ARGS_NAME
3147 Filename to read to load kernel argument parameters
3148 when reading from filesystem (for Falcon mode)
3150 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3151 Set this for NAND SPL on PPC mpc83xx targets, so that
3152 start.S waits for the rest of the SPL to load before
3153 continuing (the hardware starts execution after just
3154 loading the first page rather than the full 4K).
3156 CONFIG_SPL_SKIP_RELOCATE
3157 Avoid SPL relocation
3159 CONFIG_SPL_NAND_BASE
3160 Include nand_base.c in the SPL. Requires
3161 CONFIG_SPL_NAND_DRIVERS.
3163 CONFIG_SPL_NAND_DRIVERS
3164 SPL uses normal NAND drivers, not minimal drivers.
3167 Include standard software ECC in the SPL
3169 CONFIG_SPL_NAND_SIMPLE
3170 Support for NAND boot using simple NAND drivers that
3171 expose the cmd_ctrl() interface.
3174 Support for a lightweight UBI (fastmap) scanner and
3177 CONFIG_SPL_NAND_RAW_ONLY
3178 Support to boot only raw u-boot.bin images. Use this only
3179 if you need to save space.
3181 CONFIG_SPL_COMMON_INIT_DDR
3182 Set for common ddr init with serial presence detect in
3185 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3186 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3187 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3188 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3189 CONFIG_SYS_NAND_ECCBYTES
3190 Defines the size and behavior of the NAND that SPL uses
3193 CONFIG_SPL_NAND_BOOT
3194 Add support NAND boot
3196 CONFIG_SYS_NAND_U_BOOT_OFFS
3197 Location in NAND to read U-Boot from
3199 CONFIG_SYS_NAND_U_BOOT_DST
3200 Location in memory to load U-Boot to
3202 CONFIG_SYS_NAND_U_BOOT_SIZE
3203 Size of image to load
3205 CONFIG_SYS_NAND_U_BOOT_START
3206 Entry point in loaded image to jump to
3208 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3209 Define this if you need to first read the OOB and then the
3210 data. This is used, for example, on davinci platforms.
3212 CONFIG_SPL_OMAP3_ID_NAND
3213 Support for an OMAP3-specific set of functions to return the
3214 ID and MFR of the first attached NAND chip, if present.
3216 CONFIG_SPL_RAM_DEVICE
3217 Support for running image already present in ram, in SPL binary
3220 Image offset to which the SPL should be padded before appending
3221 the SPL payload. By default, this is defined as
3222 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3223 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3224 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3227 Final target image containing SPL and payload. Some SPLs
3228 use an arch-specific makefile fragment instead, for
3229 example if more than one image needs to be produced.
3231 CONFIG_FIT_SPL_PRINT
3232 Printing information about a FIT image adds quite a bit of
3233 code to SPL. So this is normally disabled in SPL. Use this
3234 option to re-enable it. This will affect the output of the
3235 bootm command when booting a FIT image.
3239 Enable building of TPL globally.
3242 Image offset to which the TPL should be padded before appending
3243 the TPL payload. By default, this is defined as
3244 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3245 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3246 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3248 - Interrupt support (PPC):
3250 There are common interrupt_init() and timer_interrupt()
3251 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3252 for CPU specific initialization. interrupt_init_cpu()
3253 should set decrementer_count to appropriate value. If
3254 CPU resets decrementer automatically after interrupt
3255 (ppc4xx) it should set decrementer_count to zero.
3256 timer_interrupt() calls timer_interrupt_cpu() for CPU
3257 specific handling. If board has watchdog / status_led
3258 / other_activity_monitor it works automatically from
3259 general timer_interrupt().
3262 Board initialization settings:
3263 ------------------------------
3265 During Initialization u-boot calls a number of board specific functions
3266 to allow the preparation of board specific prerequisites, e.g. pin setup
3267 before drivers are initialized. To enable these callbacks the
3268 following configuration macros have to be defined. Currently this is
3269 architecture specific, so please check arch/your_architecture/lib/board.c
3270 typically in board_init_f() and board_init_r().
3272 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3273 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3274 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3275 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3277 Configuration Settings:
3278 -----------------------
3280 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3281 Optionally it can be defined to support 64-bit memory commands.
3283 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3284 undefine this when you're short of memory.
3286 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3287 width of the commands listed in the 'help' command output.
3289 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3290 prompt for user input.
3292 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3294 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3296 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3298 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3299 the application (usually a Linux kernel) when it is
3302 - CONFIG_SYS_BAUDRATE_TABLE:
3303 List of legal baudrate settings for this board.
3305 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3306 Begin and End addresses of the area used by the
3309 - CONFIG_SYS_ALT_MEMTEST:
3310 Enable an alternate, more extensive memory test.
3312 - CONFIG_SYS_MEMTEST_SCRATCH:
3313 Scratch address used by the alternate memory test
3314 You only need to set this if address zero isn't writeable
3316 - CONFIG_SYS_MEM_RESERVE_SECURE
3317 Only implemented for ARMv8 for now.
3318 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
3319 is substracted from total RAM and won't be reported to OS.
3320 This memory can be used as secure memory. A variable
3321 gd->arch.secure_ram is used to track the location. In systems
3322 the RAM base is not zero, or RAM is divided into banks,
3323 this variable needs to be recalcuated to get the address.
3325 - CONFIG_SYS_MEM_TOP_HIDE:
3326 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3327 this specified memory area will get subtracted from the top
3328 (end) of RAM and won't get "touched" at all by U-Boot. By
3329 fixing up gd->ram_size the Linux kernel should gets passed
3330 the now "corrected" memory size and won't touch it either.
3331 This should work for arch/ppc and arch/powerpc. Only Linux
3332 board ports in arch/powerpc with bootwrapper support that
3333 recalculate the memory size from the SDRAM controller setup
3334 will have to get fixed in Linux additionally.
3336 This option can be used as a workaround for the 440EPx/GRx
3337 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3340 WARNING: Please make sure that this value is a multiple of
3341 the Linux page size (normally 4k). If this is not the case,
3342 then the end address of the Linux memory will be located at a
3343 non page size aligned address and this could cause major
3346 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3347 Enable temporary baudrate change while serial download
3349 - CONFIG_SYS_SDRAM_BASE:
3350 Physical start address of SDRAM. _Must_ be 0 here.
3352 - CONFIG_SYS_FLASH_BASE:
3353 Physical start address of Flash memory.
3355 - CONFIG_SYS_MONITOR_BASE:
3356 Physical start address of boot monitor code (set by
3357 make config files to be same as the text base address
3358 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3359 CONFIG_SYS_FLASH_BASE when booting from flash.
3361 - CONFIG_SYS_MONITOR_LEN:
3362 Size of memory reserved for monitor code, used to
3363 determine _at_compile_time_ (!) if the environment is
3364 embedded within the U-Boot image, or in a separate
3367 - CONFIG_SYS_MALLOC_LEN:
3368 Size of DRAM reserved for malloc() use.
3370 - CONFIG_SYS_MALLOC_F_LEN
3371 Size of the malloc() pool for use before relocation. If
3372 this is defined, then a very simple malloc() implementation
3373 will become available before relocation. The address is just
3374 below the global data, and the stack is moved down to make
3377 This feature allocates regions with increasing addresses
3378 within the region. calloc() is supported, but realloc()
3379 is not available. free() is supported but does nothing.
3380 The memory will be freed (or in fact just forgotten) when
3381 U-Boot relocates itself.
3383 - CONFIG_SYS_MALLOC_SIMPLE
3384 Provides a simple and small malloc() and calloc() for those
3385 boards which do not use the full malloc in SPL (which is
3386 enabled with CONFIG_SYS_SPL_MALLOC_START).
3388 - CONFIG_SYS_NONCACHED_MEMORY:
3389 Size of non-cached memory area. This area of memory will be
3390 typically located right below the malloc() area and mapped
3391 uncached in the MMU. This is useful for drivers that would
3392 otherwise require a lot of explicit cache maintenance. For
3393 some drivers it's also impossible to properly maintain the
3394 cache. For example if the regions that need to be flushed
3395 are not a multiple of the cache-line size, *and* padding
3396 cannot be allocated between the regions to align them (i.e.
3397 if the HW requires a contiguous array of regions, and the
3398 size of each region is not cache-aligned), then a flush of
3399 one region may result in overwriting data that hardware has
3400 written to another region in the same cache-line. This can
3401 happen for example in network drivers where descriptors for
3402 buffers are typically smaller than the CPU cache-line (e.g.
3403 16 bytes vs. 32 or 64 bytes).
3405 Non-cached memory is only supported on 32-bit ARM at present.
3407 - CONFIG_SYS_BOOTM_LEN:
3408 Normally compressed uImages are limited to an
3409 uncompressed size of 8 MBytes. If this is not enough,
3410 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3411 to adjust this setting to your needs.
3413 - CONFIG_SYS_BOOTMAPSZ:
3414 Maximum size of memory mapped by the startup code of
3415 the Linux kernel; all data that must be processed by
3416 the Linux kernel (bd_info, boot arguments, FDT blob if
3417 used) must be put below this limit, unless "bootm_low"
3418 environment variable is defined and non-zero. In such case
3419 all data for the Linux kernel must be between "bootm_low"
3420 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3421 variable "bootm_mapsize" will override the value of
3422 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3423 then the value in "bootm_size" will be used instead.
3425 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3426 Enable initrd_high functionality. If defined then the
3427 initrd_high feature is enabled and the bootm ramdisk subcommand
3430 - CONFIG_SYS_BOOT_GET_CMDLINE:
3431 Enables allocating and saving kernel cmdline in space between
3432 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3434 - CONFIG_SYS_BOOT_GET_KBD:
3435 Enables allocating and saving a kernel copy of the bd_info in
3436 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3438 - CONFIG_SYS_MAX_FLASH_BANKS:
3439 Max number of Flash memory banks
3441 - CONFIG_SYS_MAX_FLASH_SECT:
3442 Max number of sectors on a Flash chip
3444 - CONFIG_SYS_FLASH_ERASE_TOUT:
3445 Timeout for Flash erase operations (in ms)
3447 - CONFIG_SYS_FLASH_WRITE_TOUT:
3448 Timeout for Flash write operations (in ms)
3450 - CONFIG_SYS_FLASH_LOCK_TOUT
3451 Timeout for Flash set sector lock bit operation (in ms)
3453 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3454 Timeout for Flash clear lock bits operation (in ms)
3456 - CONFIG_SYS_FLASH_PROTECTION
3457 If defined, hardware flash sectors protection is used
3458 instead of U-Boot software protection.
3460 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3462 Enable TFTP transfers directly to flash memory;
3463 without this option such a download has to be
3464 performed in two steps: (1) download to RAM, and (2)
3465 copy from RAM to flash.
3467 The two-step approach is usually more reliable, since
3468 you can check if the download worked before you erase
3469 the flash, but in some situations (when system RAM is
3470 too limited to allow for a temporary copy of the
3471 downloaded image) this option may be very useful.
3473 - CONFIG_SYS_FLASH_CFI:
3474 Define if the flash driver uses extra elements in the
3475 common flash structure for storing flash geometry.
3477 - CONFIG_FLASH_CFI_DRIVER
3478 This option also enables the building of the cfi_flash driver
3479 in the drivers directory
3481 - CONFIG_FLASH_CFI_MTD
3482 This option enables the building of the cfi_mtd driver
3483 in the drivers directory. The driver exports CFI flash
3486 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3487 Use buffered writes to flash.
3489 - CONFIG_FLASH_SPANSION_S29WS_N
3490 s29ws-n MirrorBit flash has non-standard addresses for buffered
3493 - CONFIG_SYS_FLASH_QUIET_TEST
3494 If this option is defined, the common CFI flash doesn't
3495 print it's warning upon not recognized FLASH banks. This
3496 is useful, if some of the configured banks are only
3497 optionally available.
3499 - CONFIG_FLASH_SHOW_PROGRESS
3500 If defined (must be an integer), print out countdown
3501 digits and dots. Recommended value: 45 (9..1) for 80
3502 column displays, 15 (3..1) for 40 column displays.
3504 - CONFIG_FLASH_VERIFY
3505 If defined, the content of the flash (destination) is compared
3506 against the source after the write operation. An error message
3507 will be printed when the contents are not identical.
3508 Please note that this option is useless in nearly all cases,
3509 since such flash programming errors usually are detected earlier
3510 while unprotecting/erasing/programming. Please only enable
3511 this option if you really know what you are doing.
3513 - CONFIG_SYS_RX_ETH_BUFFER:
3514 Defines the number of Ethernet receive buffers. On some
3515 Ethernet controllers it is recommended to set this value
3516 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3517 buffers can be full shortly after enabling the interface
3518 on high Ethernet traffic.
3519 Defaults to 4 if not defined.
3521 - CONFIG_ENV_MAX_ENTRIES
3523 Maximum number of entries in the hash table that is used
3524 internally to store the environment settings. The default
3525 setting is supposed to be generous and should work in most
3526 cases. This setting can be used to tune behaviour; see
3527 lib/hashtable.c for details.
3529 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3530 - CONFIG_ENV_FLAGS_LIST_STATIC
3531 Enable validation of the values given to environment variables when
3532 calling env set. Variables can be restricted to only decimal,
3533 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3534 the variables can also be restricted to IP address or MAC address.
3536 The format of the list is:
3537 type_attribute = [s|d|x|b|i|m]
3538 access_attribute = [a|r|o|c]
3539 attributes = type_attribute[access_attribute]
3540 entry = variable_name[:attributes]
3543 The type attributes are:
3544 s - String (default)
3547 b - Boolean ([1yYtT|0nNfF])
3551 The access attributes are:
3557 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3558 Define this to a list (string) to define the ".flags"
3559 environment variable in the default or embedded environment.
3561 - CONFIG_ENV_FLAGS_LIST_STATIC
3562 Define this to a list (string) to define validation that
3563 should be done if an entry is not found in the ".flags"
3564 environment variable. To override a setting in the static
3565 list, simply add an entry for the same variable name to the
3568 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
3569 regular expression. This allows multiple variables to define the same
3570 flags without explicitly listing them for each variable.
3572 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3573 If defined, don't allow the -f switch to env set override variable
3577 If stdint.h is available with your toolchain you can define this
3578 option to enable it. You can provide option 'USE_STDINT=1' when
3579 building U-Boot to enable this.
3581 The following definitions that deal with the placement and management
3582 of environment data (variable area); in general, we support the
3583 following configurations:
3585 - CONFIG_BUILD_ENVCRC:
3587 Builds up envcrc with the target environment so that external utils
3588 may easily extract it and embed it in final U-Boot images.
3590 - CONFIG_ENV_IS_IN_FLASH:
3592 Define this if the environment is in flash memory.
3594 a) The environment occupies one whole flash sector, which is
3595 "embedded" in the text segment with the U-Boot code. This
3596 happens usually with "bottom boot sector" or "top boot
3597 sector" type flash chips, which have several smaller
3598 sectors at the start or the end. For instance, such a
3599 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3600 such a case you would place the environment in one of the
3601 4 kB sectors - with U-Boot code before and after it. With
3602 "top boot sector" type flash chips, you would put the
3603 environment in one of the last sectors, leaving a gap
3604 between U-Boot and the environment.
3606 - CONFIG_ENV_OFFSET:
3608 Offset of environment data (variable area) to the
3609 beginning of flash memory; for instance, with bottom boot
3610 type flash chips the second sector can be used: the offset
3611 for this sector is given here.
3613 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3617 This is just another way to specify the start address of
3618 the flash sector containing the environment (instead of
3621 - CONFIG_ENV_SECT_SIZE:
3623 Size of the sector containing the environment.
3626 b) Sometimes flash chips have few, equal sized, BIG sectors.
3627 In such a case you don't want to spend a whole sector for
3632 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3633 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3634 of this flash sector for the environment. This saves
3635 memory for the RAM copy of the environment.
3637 It may also save flash memory if you decide to use this
3638 when your environment is "embedded" within U-Boot code,
3639 since then the remainder of the flash sector could be used
3640 for U-Boot code. It should be pointed out that this is
3641 STRONGLY DISCOURAGED from a robustness point of view:
3642 updating the environment in flash makes it always
3643 necessary to erase the WHOLE sector. If something goes
3644 wrong before the contents has been restored from a copy in
3645 RAM, your target system will be dead.
3647 - CONFIG_ENV_ADDR_REDUND
3648 CONFIG_ENV_SIZE_REDUND
3650 These settings describe a second storage area used to hold
3651 a redundant copy of the environment data, so that there is
3652 a valid backup copy in case there is a power failure during
3653 a "saveenv" operation.
3655 BE CAREFUL! Any changes to the flash layout, and some changes to the
3656 source code will make it necessary to adapt <board>/u-boot.lds*
3660 - CONFIG_ENV_IS_IN_NVRAM:
3662 Define this if you have some non-volatile memory device
3663 (NVRAM, battery buffered SRAM) which you want to use for the
3669 These two #defines are used to determine the memory area you
3670 want to use for environment. It is assumed that this memory
3671 can just be read and written to, without any special
3674 BE CAREFUL! The first access to the environment happens quite early
3675 in U-Boot initialization (when we try to get the setting of for the
3676 console baudrate). You *MUST* have mapped your NVRAM area then, or
3679 Please note that even with NVRAM we still use a copy of the
3680 environment in RAM: we could work on NVRAM directly, but we want to
3681 keep settings there always unmodified except somebody uses "saveenv"
3682 to save the current settings.
3685 - CONFIG_ENV_IS_IN_EEPROM:
3687 Use this if you have an EEPROM or similar serial access
3688 device and a driver for it.
3690 - CONFIG_ENV_OFFSET:
3693 These two #defines specify the offset and size of the
3694 environment area within the total memory of your EEPROM.
3696 - CONFIG_SYS_I2C_EEPROM_ADDR:
3697 If defined, specified the chip address of the EEPROM device.
3698 The default address is zero.
3700 - CONFIG_SYS_I2C_EEPROM_BUS:
3701 If defined, specified the i2c bus of the EEPROM device.
3703 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3704 If defined, the number of bits used to address bytes in a
3705 single page in the EEPROM device. A 64 byte page, for example
3706 would require six bits.
3708 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3709 If defined, the number of milliseconds to delay between
3710 page writes. The default is zero milliseconds.
3712 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3713 The length in bytes of the EEPROM memory array address. Note
3714 that this is NOT the chip address length!
3716 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3717 EEPROM chips that implement "address overflow" are ones
3718 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3719 address and the extra bits end up in the "chip address" bit
3720 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3723 Note that we consider the length of the address field to
3724 still be one byte because the extra address bits are hidden
3725 in the chip address.
3727 - CONFIG_SYS_EEPROM_SIZE:
3728 The size in bytes of the EEPROM device.
3730 - CONFIG_ENV_EEPROM_IS_ON_I2C
3731 define this, if you have I2C and SPI activated, and your
3732 EEPROM, which holds the environment, is on the I2C bus.
3734 - CONFIG_I2C_ENV_EEPROM_BUS
3735 if you have an Environment on an EEPROM reached over
3736 I2C muxes, you can define here, how to reach this
3737 EEPROM. For example:
3739 #define CONFIG_I2C_ENV_EEPROM_BUS 1
3741 EEPROM which holds the environment, is reached over
3742 a pca9547 i2c mux with address 0x70, channel 3.
3744 - CONFIG_ENV_IS_IN_DATAFLASH:
3746 Define this if you have a DataFlash memory device which you
3747 want to use for the environment.
3749 - CONFIG_ENV_OFFSET:
3753 These three #defines specify the offset and size of the
3754 environment area within the total memory of your DataFlash placed
3755 at the specified address.
3757 - CONFIG_ENV_IS_IN_SPI_FLASH:
3759 Define this if you have a SPI Flash memory device which you
3760 want to use for the environment.
3762 - CONFIG_ENV_OFFSET:
3765 These two #defines specify the offset and size of the
3766 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
3767 aligned to an erase sector boundary.
3769 - CONFIG_ENV_SECT_SIZE:
3771 Define the SPI flash's sector size.
3773 - CONFIG_ENV_OFFSET_REDUND (optional):
3775 This setting describes a second storage area of CONFIG_ENV_SIZE
3776 size used to hold a redundant copy of the environment data, so
3777 that there is a valid backup copy in case there is a power failure
3778 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be
3779 aligned to an erase sector boundary.
3781 - CONFIG_ENV_SPI_BUS (optional):
3782 - CONFIG_ENV_SPI_CS (optional):
3784 Define the SPI bus and chip select. If not defined they will be 0.
3786 - CONFIG_ENV_SPI_MAX_HZ (optional):
3788 Define the SPI max work clock. If not defined then use 1MHz.
3790 - CONFIG_ENV_SPI_MODE (optional):
3792 Define the SPI work mode. If not defined then use SPI_MODE_3.
3794 - CONFIG_ENV_IS_IN_REMOTE:
3796 Define this if you have a remote memory space which you
3797 want to use for the local device's environment.
3802 These two #defines specify the address and size of the
3803 environment area within the remote memory space. The
3804 local device can get the environment from remote memory
3805 space by SRIO or PCIE links.
3807 BE CAREFUL! For some special cases, the local device can not use
3808 "saveenv" command. For example, the local device will get the
3809 environment stored in a remote NOR flash by SRIO or PCIE link,
3810 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3812 - CONFIG_ENV_IS_IN_NAND:
3814 Define this if you have a NAND device which you want to use
3815 for the environment.
3817 - CONFIG_ENV_OFFSET:
3820 These two #defines specify the offset and size of the environment
3821 area within the first NAND device. CONFIG_ENV_OFFSET must be
3822 aligned to an erase block boundary.
3824 - CONFIG_ENV_OFFSET_REDUND (optional):
3826 This setting describes a second storage area of CONFIG_ENV_SIZE
3827 size used to hold a redundant copy of the environment data, so
3828 that there is a valid backup copy in case there is a power failure
3829 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be
3830 aligned to an erase block boundary.
3832 - CONFIG_ENV_RANGE (optional):
3834 Specifies the length of the region in which the environment
3835 can be written. This should be a multiple of the NAND device's
3836 block size. Specifying a range with more erase blocks than
3837 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3838 the range to be avoided.
3840 - CONFIG_ENV_OFFSET_OOB (optional):
3842 Enables support for dynamically retrieving the offset of the
3843 environment from block zero's out-of-band data. The
3844 "nand env.oob" command can be used to record this offset.
3845 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3846 using CONFIG_ENV_OFFSET_OOB.
3848 - CONFIG_NAND_ENV_DST
3850 Defines address in RAM to which the nand_spl code should copy the
3851 environment. If redundant environment is used, it will be copied to
3852 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3854 - CONFIG_ENV_IS_IN_UBI:
3856 Define this if you have an UBI volume that you want to use for the
3857 environment. This has the benefit of wear-leveling the environment
3858 accesses, which is important on NAND.
3860 - CONFIG_ENV_UBI_PART:
3862 Define this to a string that is the mtd partition containing the UBI.
3864 - CONFIG_ENV_UBI_VOLUME:
3866 Define this to the name of the volume that you want to store the
3869 - CONFIG_ENV_UBI_VOLUME_REDUND:
3871 Define this to the name of another volume to store a second copy of
3872 the environment in. This will enable redundant environments in UBI.
3873 It is assumed that both volumes are in the same MTD partition.
3875 - CONFIG_UBI_SILENCE_MSG
3876 - CONFIG_UBIFS_SILENCE_MSG
3878 You will probably want to define these to avoid a really noisy system
3879 when storing the env in UBI.
3881 - CONFIG_ENV_IS_IN_FAT:
3882 Define this if you want to use the FAT file system for the environment.
3884 - FAT_ENV_INTERFACE:
3886 Define this to a string that is the name of the block device.
3888 - FAT_ENV_DEVICE_AND_PART:
3890 Define this to a string to specify the partition of the device. It can
3893 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
3894 - "D:P": device D partition P. Error occurs if device D has no
3897 - "D" or "D:": device D partition 1 if device D has partition
3898 table, or the whole device D if has no partition
3900 - "D:auto": first partition in device D with bootable flag set.
3901 If none, first valid partition in device D. If no
3902 partition table then means device D.
3906 It's a string of the FAT file name. This file use to store the
3910 This should be defined. Otherwise it cannot save the environment file.
3912 - CONFIG_ENV_IS_IN_MMC:
3914 Define this if you have an MMC device which you want to use for the
3917 - CONFIG_SYS_MMC_ENV_DEV:
3919 Specifies which MMC device the environment is stored in.
3921 - CONFIG_SYS_MMC_ENV_PART (optional):
3923 Specifies which MMC partition the environment is stored in. If not
3924 set, defaults to partition 0, the user area. Common values might be
3925 1 (first MMC boot partition), 2 (second MMC boot partition).
3927 - CONFIG_ENV_OFFSET:
3930 These two #defines specify the offset and size of the environment
3931 area within the specified MMC device.
3933 If offset is positive (the usual case), it is treated as relative to
3934 the start of the MMC partition. If offset is negative, it is treated
3935 as relative to the end of the MMC partition. This can be useful if
3936 your board may be fitted with different MMC devices, which have
3937 different sizes for the MMC partitions, and you always want the
3938 environment placed at the very end of the partition, to leave the
3939 maximum possible space before it, to store other data.
3941 These two values are in units of bytes, but must be aligned to an
3942 MMC sector boundary.
3944 - CONFIG_ENV_OFFSET_REDUND (optional):
3946 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
3947 hold a redundant copy of the environment data. This provides a
3948 valid backup copy in case the other copy is corrupted, e.g. due
3949 to a power failure during a "saveenv" operation.
3951 This value may also be positive or negative; this is handled in the
3952 same way as CONFIG_ENV_OFFSET.
3954 This value is also in units of bytes, but must also be aligned to
3955 an MMC sector boundary.
3957 - CONFIG_ENV_SIZE_REDUND (optional):
3959 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
3960 set. If this value is set, it must be set to the same value as
3963 - CONFIG_SYS_SPI_INIT_OFFSET
3965 Defines offset to the initial SPI buffer area in DPRAM. The
3966 area is used at an early stage (ROM part) if the environment
3967 is configured to reside in the SPI EEPROM: We need a 520 byte
3968 scratch DPRAM area. It is used between the two initialization
3969 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
3970 to be a good choice since it makes it far enough from the
3971 start of the data area as well as from the stack pointer.
3973 Please note that the environment is read-only until the monitor
3974 has been relocated to RAM and a RAM copy of the environment has been
3975 created; also, when using EEPROM you will have to use getenv_f()
3976 until then to read environment variables.
3978 The environment is protected by a CRC32 checksum. Before the monitor
3979 is relocated into RAM, as a result of a bad CRC you will be working
3980 with the compiled-in default environment - *silently*!!! [This is
3981 necessary, because the first environment variable we need is the
3982 "baudrate" setting for the console - if we have a bad CRC, we don't
3983 have any device yet where we could complain.]
3985 Note: once the monitor has been relocated, then it will complain if
3986 the default environment is used; a new CRC is computed as soon as you
3987 use the "saveenv" command to store a valid environment.
3989 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3990 Echo the inverted Ethernet link state to the fault LED.
3992 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3993 also needs to be defined.
3995 - CONFIG_SYS_FAULT_MII_ADDR:
3996 MII address of the PHY to check for the Ethernet link state.
3998 - CONFIG_NS16550_MIN_FUNCTIONS:
3999 Define this if you desire to only have use of the NS16550_init
4000 and NS16550_putc functions for the serial driver located at
4001 drivers/serial/ns16550.c. This option is useful for saving
4002 space for already greatly restricted images, including but not
4003 limited to NAND_SPL configurations.
4005 - CONFIG_DISPLAY_BOARDINFO
4006 Display information about the board that U-Boot is running on
4007 when U-Boot starts up. The board function checkboard() is called
4010 - CONFIG_DISPLAY_BOARDINFO_LATE
4011 Similar to the previous option, but display this information
4012 later, once stdio is running and output goes to the LCD, if
4015 - CONFIG_BOARD_SIZE_LIMIT:
4016 Maximum size of the U-Boot image. When defined, the
4017 build system checks that the actual size does not
4020 Low Level (hardware related) configuration options:
4021 ---------------------------------------------------
4023 - CONFIG_SYS_CACHELINE_SIZE:
4024 Cache Line Size of the CPU.
4026 - CONFIG_SYS_DEFAULT_IMMR:
4027 Default address of the IMMR after system reset.
4029 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4030 and RPXsuper) to be able to adjust the position of
4031 the IMMR register after a reset.
4033 - CONFIG_SYS_CCSRBAR_DEFAULT:
4034 Default (power-on reset) physical address of CCSR on Freescale
4037 - CONFIG_SYS_CCSRBAR:
4038 Virtual address of CCSR. On a 32-bit build, this is typically
4039 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4041 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4042 for cross-platform code that uses that macro instead.
4044 - CONFIG_SYS_CCSRBAR_PHYS:
4045 Physical address of CCSR. CCSR can be relocated to a new
4046 physical address, if desired. In this case, this macro should
4047 be set to that address. Otherwise, it should be set to the
4048 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4049 is typically relocated on 36-bit builds. It is recommended
4050 that this macro be defined via the _HIGH and _LOW macros:
4052 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4053 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4055 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4056 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4057 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4058 used in assembly code, so it must not contain typecasts or
4059 integer size suffixes (e.g. "ULL").
4061 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4062 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4063 used in assembly code, so it must not contain typecasts or
4064 integer size suffixes (e.g. "ULL").
4066 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4067 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4068 forced to a value that ensures that CCSR is not relocated.
4070 - Floppy Disk Support:
4071 CONFIG_SYS_FDC_DRIVE_NUMBER
4073 the default drive number (default value 0)
4075 CONFIG_SYS_ISA_IO_STRIDE
4077 defines the spacing between FDC chipset registers
4080 CONFIG_SYS_ISA_IO_OFFSET
4082 defines the offset of register from address. It
4083 depends on which part of the data bus is connected to
4084 the FDC chipset. (default value 0)
4086 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4087 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4090 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4091 fdc_hw_init() is called at the beginning of the FDC
4092 setup. fdc_hw_init() must be provided by the board
4093 source code. It is used to make hardware-dependent
4097 Most IDE controllers were designed to be connected with PCI
4098 interface. Only few of them were designed for AHB interface.
4099 When software is doing ATA command and data transfer to
4100 IDE devices through IDE-AHB controller, some additional
4101 registers accessing to these kind of IDE-AHB controller
4104 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4105 DO NOT CHANGE unless you know exactly what you're
4106 doing! (11-4) [MPC8xx/82xx systems only]
4108 - CONFIG_SYS_INIT_RAM_ADDR:
4110 Start address of memory area that can be used for
4111 initial data and stack; please note that this must be
4112 writable memory that is working WITHOUT special
4113 initialization, i. e. you CANNOT use normal RAM which
4114 will become available only after programming the
4115 memory controller and running certain initialization
4118 U-Boot uses the following memory types:
4119 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4120 - MPC824X: data cache
4121 - PPC4xx: data cache
4123 - CONFIG_SYS_GBL_DATA_OFFSET:
4125 Offset of the initial data structure in the memory
4126 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4127 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4128 data is located at the end of the available space
4129 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4130 GENERATED_GBL_DATA_SIZE), and the initial stack is just
4131 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4132 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4135 On the MPC824X (or other systems that use the data
4136 cache for initial memory) the address chosen for
4137 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4138 point to an otherwise UNUSED address space between
4139 the top of RAM and the start of the PCI space.
4141 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4143 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4145 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4147 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4149 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4151 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4153 - CONFIG_SYS_OR_TIMING_SDRAM:
4156 - CONFIG_SYS_MAMR_PTA:
4157 periodic timer for refresh
4159 - CONFIG_SYS_DER: Debug Event Register (37-47)
4161 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4162 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4163 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4164 CONFIG_SYS_BR1_PRELIM:
4165 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4167 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4168 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4169 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4170 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4172 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4173 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4174 Machine Mode Register and Memory Periodic Timer
4175 Prescaler definitions (SDRAM timing)
4177 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4178 enable I2C microcode relocation patch (MPC8xx);
4179 define relocation offset in DPRAM [DSP2]
4181 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4182 enable SMC microcode relocation patch (MPC8xx);
4183 define relocation offset in DPRAM [SMC1]
4185 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4186 enable SPI microcode relocation patch (MPC8xx);
4187 define relocation offset in DPRAM [SCC4]
4189 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4190 Offset of the bootmode word in DPRAM used by post
4191 (Power On Self Tests). This definition overrides
4192 #define'd default value in commproc.h resp.
4195 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4196 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4197 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4198 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4199 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4200 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4201 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4202 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4203 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4205 - CONFIG_PCI_DISABLE_PCIE:
4206 Disable PCI-Express on systems where it is supported but not
4209 - CONFIG_PCI_ENUM_ONLY
4210 Only scan through and get the devices on the buses.
4211 Don't do any setup work, presumably because someone or
4212 something has already done it, and we don't need to do it
4213 a second time. Useful for platforms that are pre-booted
4214 by coreboot or similar.
4216 - CONFIG_PCI_INDIRECT_BRIDGE:
4217 Enable support for indirect PCI bridges.
4220 Chip has SRIO or not
4223 Board has SRIO 1 port available
4226 Board has SRIO 2 port available
4228 - CONFIG_SRIO_PCIE_BOOT_MASTER
4229 Board can support master function for Boot from SRIO and PCIE
4231 - CONFIG_SYS_SRIOn_MEM_VIRT:
4232 Virtual Address of SRIO port 'n' memory region
4234 - CONFIG_SYS_SRIOn_MEM_PHYS:
4235 Physical Address of SRIO port 'n' memory region
4237 - CONFIG_SYS_SRIOn_MEM_SIZE:
4238 Size of SRIO port 'n' memory region
4240 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4241 Defined to tell the NAND controller that the NAND chip is using
4243 Not all NAND drivers use this symbol.
4244 Example of drivers that use it:
4245 - drivers/mtd/nand/ndfc.c
4246 - drivers/mtd/nand/mxc_nand.c
4248 - CONFIG_SYS_NDFC_EBC0_CFG
4249 Sets the EBC0_CFG register for the NDFC. If not defined
4250 a default value will be used.
4253 Get DDR timing information from an I2C EEPROM. Common
4254 with pluggable memory modules such as SODIMMs
4257 I2C address of the SPD EEPROM
4259 - CONFIG_SYS_SPD_BUS_NUM
4260 If SPD EEPROM is on an I2C bus other than the first
4261 one, specify here. Note that the value must resolve
4262 to something your driver can deal with.
4264 - CONFIG_SYS_DDR_RAW_TIMING
4265 Get DDR timing information from other than SPD. Common with
4266 soldered DDR chips onboard without SPD. DDR raw timing
4267 parameters are extracted from datasheet and hard-coded into
4268 header files or board specific files.
4270 - CONFIG_FSL_DDR_INTERACTIVE
4271 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4273 - CONFIG_FSL_DDR_SYNC_REFRESH
4274 Enable sync of refresh for multiple controllers.
4276 - CONFIG_FSL_DDR_BIST
4277 Enable built-in memory test for Freescale DDR controllers.
4279 - CONFIG_SYS_83XX_DDR_USES_CS0
4280 Only for 83xx systems. If specified, then DDR should
4281 be configured using CS0 and CS1 instead of CS2 and CS3.
4283 - CONFIG_ETHER_ON_FEC[12]
4284 Define to enable FEC[12] on a 8xx series processor.
4286 - CONFIG_FEC[12]_PHY
4287 Define to the hardcoded PHY address which corresponds
4288 to the given FEC; i. e.
4289 #define CONFIG_FEC1_PHY 4
4290 means that the PHY with address 4 is connected to FEC1
4292 When set to -1, means to probe for first available.
4294 - CONFIG_FEC[12]_PHY_NORXERR
4295 The PHY does not have a RXERR line (RMII only).
4296 (so program the FEC to ignore it).
4299 Enable RMII mode for all FECs.
4300 Note that this is a global option, we can't
4301 have one FEC in standard MII mode and another in RMII mode.
4303 - CONFIG_CRC32_VERIFY
4304 Add a verify option to the crc32 command.
4307 => crc32 -v <address> <count> <crc32>
4309 Where address/count indicate a memory area
4310 and crc32 is the correct crc32 which the
4314 Add the "loopw" memory command. This only takes effect if
4315 the memory commands are activated globally (CONFIG_CMD_MEM).
4318 Add the "mdc" and "mwc" memory commands. These are cyclic
4323 This command will print 4 bytes (10,11,12,13) each 500 ms.
4325 => mwc.l 100 12345678 10
4326 This command will write 12345678 to address 100 all 10 ms.
4328 This only takes effect if the memory commands are activated
4329 globally (CONFIG_CMD_MEM).
4331 - CONFIG_SKIP_LOWLEVEL_INIT
4332 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4333 low level initializations (like setting up the memory
4334 controller) are omitted and/or U-Boot does not
4335 relocate itself into RAM.
4337 Normally this variable MUST NOT be defined. The only
4338 exception is when U-Boot is loaded (to RAM) by some
4339 other boot loader or by a debugger which performs
4340 these initializations itself.
4342 - CONFIG_SKIP_LOWLEVEL_INIT_ONLY
4343 [ARM926EJ-S only] This allows just the call to lowlevel_init()
4344 to be skipped. The normal CP15 init (such as enabling the
4345 instruction cache) is still performed.
4348 Modifies the behaviour of start.S when compiling a loader
4349 that is executed before the actual U-Boot. E.g. when
4350 compiling a NAND SPL.
4353 Modifies the behaviour of start.S when compiling a loader
4354 that is executed after the SPL and before the actual U-Boot.
4355 It is loaded by the SPL.
4357 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4358 Only for 85xx systems. If this variable is specified, the section
4359 .resetvec is not kept and the section .bootpg is placed in the
4360 previous 4k of the .text section.
4362 - CONFIG_ARCH_MAP_SYSMEM
4363 Generally U-Boot (and in particular the md command) uses
4364 effective address. It is therefore not necessary to regard
4365 U-Boot address as virtual addresses that need to be translated
4366 to physical addresses. However, sandbox requires this, since
4367 it maintains its own little RAM buffer which contains all
4368 addressable memory. This option causes some memory accesses
4369 to be mapped through map_sysmem() / unmap_sysmem().
4371 - CONFIG_X86_RESET_VECTOR
4372 If defined, the x86 reset vector code is included. This is not
4373 needed when U-Boot is running from Coreboot.
4375 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4376 Enables the RTC32K OSC on AM33xx based plattforms
4378 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4379 Option to disable subpage write in NAND driver
4380 driver that uses this:
4381 drivers/mtd/nand/davinci_nand.c
4383 Freescale QE/FMAN Firmware Support:
4384 -----------------------------------
4386 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4387 loading of "firmware", which is encoded in the QE firmware binary format.
4388 This firmware often needs to be loaded during U-Boot booting, so macros
4389 are used to identify the storage device (NOR flash, SPI, etc) and the address
4392 - CONFIG_SYS_FMAN_FW_ADDR
4393 The address in the storage device where the FMAN microcode is located. The
4394 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4397 - CONFIG_SYS_QE_FW_ADDR
4398 The address in the storage device where the QE microcode is located. The
4399 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4402 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4403 The maximum possible size of the firmware. The firmware binary format
4404 has a field that specifies the actual size of the firmware, but it
4405 might not be possible to read any part of the firmware unless some
4406 local storage is allocated to hold the entire firmware first.
4408 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4409 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4410 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4411 virtual address in NOR flash.
4413 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4414 Specifies that QE/FMAN firmware is located in NAND flash.
4415 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4417 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4418 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4419 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4421 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4422 Specifies that QE/FMAN firmware is located in the remote (master)
4423 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4424 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4425 window->master inbound window->master LAW->the ucode address in
4426 master's memory space.
4428 Freescale Layerscape Management Complex Firmware Support:
4429 ---------------------------------------------------------
4430 The Freescale Layerscape Management Complex (MC) supports the loading of
4432 This firmware often needs to be loaded during U-Boot booting, so macros
4433 are used to identify the storage device (NOR flash, SPI, etc) and the address
4436 - CONFIG_FSL_MC_ENET
4437 Enable the MC driver for Layerscape SoCs.
4439 Freescale Layerscape Debug Server Support:
4440 -------------------------------------------
4441 The Freescale Layerscape Debug Server Support supports the loading of
4442 "Debug Server firmware" and triggering SP boot-rom.
4443 This firmware often needs to be loaded during U-Boot booting.
4445 - CONFIG_SYS_MC_RSV_MEM_ALIGN
4446 Define alignment of reserved memory MC requires
4451 In order to achieve reproducible builds, timestamps used in the U-Boot build
4452 process have to be set to a fixed value.
4454 This is done using the SOURCE_DATE_EPOCH environment variable.
4455 SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
4456 option for U-Boot or an environment variable in U-Boot.
4458 SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
4460 Building the Software:
4461 ======================
4463 Building U-Boot has been tested in several native build environments
4464 and in many different cross environments. Of course we cannot support
4465 all possibly existing versions of cross development tools in all
4466 (potentially obsolete) versions. In case of tool chain problems we
4467 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4468 which is extensively used to build and test U-Boot.
4470 If you are not using a native environment, it is assumed that you
4471 have GNU cross compiling tools available in your path. In this case,
4472 you must set the environment variable CROSS_COMPILE in your shell.
4473 Note that no changes to the Makefile or any other source files are
4474 necessary. For example using the ELDK on a 4xx CPU, please enter:
4476 $ CROSS_COMPILE=ppc_4xx-
4477 $ export CROSS_COMPILE
4479 Note: If you wish to generate Windows versions of the utilities in
4480 the tools directory you can use the MinGW toolchain
4481 (http://www.mingw.org). Set your HOST tools to the MinGW
4482 toolchain and execute 'make tools'. For example:
4484 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4486 Binaries such as tools/mkimage.exe will be created which can
4487 be executed on computers running Windows.
4489 U-Boot is intended to be simple to build. After installing the
4490 sources you must configure U-Boot for one specific board type. This
4495 where "NAME_defconfig" is the name of one of the existing configu-
4496 rations; see boards.cfg for supported names.
4498 Note: for some board special configuration names may exist; check if
4499 additional information is available from the board vendor; for
4500 instance, the TQM823L systems are available without (standard)
4501 or with LCD support. You can select such additional "features"
4502 when choosing the configuration, i. e.
4504 make TQM823L_defconfig
4505 - will configure for a plain TQM823L, i. e. no LCD support
4507 make TQM823L_LCD_defconfig
4508 - will configure for a TQM823L with U-Boot console on LCD
4513 Finally, type "make all", and you should get some working U-Boot
4514 images ready for download to / installation on your system:
4516 - "u-boot.bin" is a raw binary image
4517 - "u-boot" is an image in ELF binary format
4518 - "u-boot.srec" is in Motorola S-Record format
4520 By default the build is performed locally and the objects are saved
4521 in the source directory. One of the two methods can be used to change
4522 this behavior and build U-Boot to some external directory:
4524 1. Add O= to the make command line invocations:
4526 make O=/tmp/build distclean
4527 make O=/tmp/build NAME_defconfig
4528 make O=/tmp/build all
4530 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
4532 export KBUILD_OUTPUT=/tmp/build
4537 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
4541 Please be aware that the Makefiles assume you are using GNU make, so
4542 for instance on NetBSD you might need to use "gmake" instead of
4546 If the system board that you have is not listed, then you will need
4547 to port U-Boot to your hardware platform. To do this, follow these
4550 1. Create a new directory to hold your board specific code. Add any
4551 files you need. In your board directory, you will need at least
4552 the "Makefile" and a "<board>.c".
4553 2. Create a new configuration file "include/configs/<board>.h" for
4555 3. If you're porting U-Boot to a new CPU, then also create a new
4556 directory to hold your CPU specific code. Add any files you need.
4557 4. Run "make <board>_defconfig" with your new name.
4558 5. Type "make", and you should get a working "u-boot.srec" file
4559 to be installed on your target system.
4560 6. Debug and solve any problems that might arise.
4561 [Of course, this last step is much harder than it sounds.]
4564 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4565 ==============================================================
4567 If you have modified U-Boot sources (for instance added a new board
4568 or support for new devices, a new CPU, etc.) you are expected to
4569 provide feedback to the other developers. The feedback normally takes
4570 the form of a "patch", i. e. a context diff against a certain (latest
4571 official or latest in the git repository) version of U-Boot sources.
4573 But before you submit such a patch, please verify that your modifi-
4574 cation did not break existing code. At least make sure that *ALL* of
4575 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4576 just run the buildman script (tools/buildman/buildman), which will
4577 configure and build U-Boot for ALL supported system. Be warned, this
4578 will take a while. Please see the buildman README, or run 'buildman -H'
4582 See also "U-Boot Porting Guide" below.
4585 Monitor Commands - Overview:
4586 ============================
4588 go - start application at address 'addr'
4589 run - run commands in an environment variable
4590 bootm - boot application image from memory
4591 bootp - boot image via network using BootP/TFTP protocol
4592 bootz - boot zImage from memory
4593 tftpboot- boot image via network using TFTP protocol
4594 and env variables "ipaddr" and "serverip"
4595 (and eventually "gatewayip")
4596 tftpput - upload a file via network using TFTP protocol
4597 rarpboot- boot image via network using RARP/TFTP protocol
4598 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4599 loads - load S-Record file over serial line
4600 loadb - load binary file over serial line (kermit mode)
4602 mm - memory modify (auto-incrementing)
4603 nm - memory modify (constant address)
4604 mw - memory write (fill)
4606 cmp - memory compare
4607 crc32 - checksum calculation
4608 i2c - I2C sub-system
4609 sspi - SPI utility commands
4610 base - print or set address offset
4611 printenv- print environment variables
4612 setenv - set environment variables
4613 saveenv - save environment variables to persistent storage
4614 protect - enable or disable FLASH write protection
4615 erase - erase FLASH memory
4616 flinfo - print FLASH memory information
4617 nand - NAND memory operations (see doc/README.nand)
4618 bdinfo - print Board Info structure
4619 iminfo - print header information for application image
4620 coninfo - print console devices and informations
4621 ide - IDE sub-system
4622 loop - infinite loop on address range
4623 loopw - infinite write loop on address range
4624 mtest - simple RAM test
4625 icache - enable or disable instruction cache
4626 dcache - enable or disable data cache
4627 reset - Perform RESET of the CPU
4628 echo - echo args to console
4629 version - print monitor version
4630 help - print online help
4631 ? - alias for 'help'
4634 Monitor Commands - Detailed Description:
4635 ========================================
4639 For now: just type "help <command>".
4642 Environment Variables:
4643 ======================
4645 U-Boot supports user configuration using Environment Variables which
4646 can be made persistent by saving to Flash memory.
4648 Environment Variables are set using "setenv", printed using
4649 "printenv", and saved to Flash using "saveenv". Using "setenv"
4650 without a value can be used to delete a variable from the
4651 environment. As long as you don't save the environment you are
4652 working with an in-memory copy. In case the Flash area containing the
4653 environment is erased by accident, a default environment is provided.
4655 Some configuration options can be set using Environment Variables.
4657 List of environment variables (most likely not complete):
4659 baudrate - see CONFIG_BAUDRATE
4661 bootdelay - see CONFIG_BOOTDELAY
4663 bootcmd - see CONFIG_BOOTCOMMAND
4665 bootargs - Boot arguments when booting an RTOS image
4667 bootfile - Name of the image to load with TFTP
4669 bootm_low - Memory range available for image processing in the bootm
4670 command can be restricted. This variable is given as
4671 a hexadecimal number and defines lowest address allowed
4672 for use by the bootm command. See also "bootm_size"
4673 environment variable. Address defined by "bootm_low" is
4674 also the base of the initial memory mapping for the Linux
4675 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4678 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4679 This variable is given as a hexadecimal number and it
4680 defines the size of the memory region starting at base
4681 address bootm_low that is accessible by the Linux kernel
4682 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4683 as the default value if it is defined, and bootm_size is
4686 bootm_size - Memory range available for image processing in the bootm
4687 command can be restricted. This variable is given as
4688 a hexadecimal number and defines the size of the region
4689 allowed for use by the bootm command. See also "bootm_low"
4690 environment variable.
4692 updatefile - Location of the software update file on a TFTP server, used
4693 by the automatic software update feature. Please refer to
4694 documentation in doc/README.update for more details.
4696 autoload - if set to "no" (any string beginning with 'n'),
4697 "bootp" will just load perform a lookup of the
4698 configuration from the BOOTP server, but not try to
4699 load any image using TFTP
4701 autostart - if set to "yes", an image loaded using the "bootp",
4702 "rarpboot", "tftpboot" or "diskboot" commands will
4703 be automatically started (by internally calling
4706 If set to "no", a standalone image passed to the
4707 "bootm" command will be copied to the load address
4708 (and eventually uncompressed), but NOT be started.
4709 This can be used to load and uncompress arbitrary
4712 fdt_high - if set this restricts the maximum address that the
4713 flattened device tree will be copied into upon boot.
4714 For example, if you have a system with 1 GB memory
4715 at physical address 0x10000000, while Linux kernel
4716 only recognizes the first 704 MB as low memory, you
4717 may need to set fdt_high as 0x3C000000 to have the
4718 device tree blob be copied to the maximum address
4719 of the 704 MB low memory, so that Linux kernel can
4720 access it during the boot procedure.
4722 If this is set to the special value 0xFFFFFFFF then
4723 the fdt will not be copied at all on boot. For this
4724 to work it must reside in writable memory, have
4725 sufficient padding on the end of it for u-boot to
4726 add the information it needs into it, and the memory
4727 must be accessible by the kernel.
4729 fdtcontroladdr- if set this is the address of the control flattened
4730 device tree used by U-Boot when CONFIG_OF_CONTROL is
4733 i2cfast - (PPC405GP|PPC405EP only)
4734 if set to 'y' configures Linux I2C driver for fast
4735 mode (400kHZ). This environment variable is used in
4736 initialization code. So, for changes to be effective
4737 it must be saved and board must be reset.
4739 initrd_high - restrict positioning of initrd images:
4740 If this variable is not set, initrd images will be
4741 copied to the highest possible address in RAM; this
4742 is usually what you want since it allows for
4743 maximum initrd size. If for some reason you want to
4744 make sure that the initrd image is loaded below the
4745 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4746 variable to a value of "no" or "off" or "0".
4747 Alternatively, you can set it to a maximum upper
4748 address to use (U-Boot will still check that it
4749 does not overwrite the U-Boot stack and data).
4751 For instance, when you have a system with 16 MB
4752 RAM, and want to reserve 4 MB from use by Linux,
4753 you can do this by adding "mem=12M" to the value of
4754 the "bootargs" variable. However, now you must make
4755 sure that the initrd image is placed in the first
4756 12 MB as well - this can be done with
4758 setenv initrd_high 00c00000
4760 If you set initrd_high to 0xFFFFFFFF, this is an
4761 indication to U-Boot that all addresses are legal
4762 for the Linux kernel, including addresses in flash
4763 memory. In this case U-Boot will NOT COPY the
4764 ramdisk at all. This may be useful to reduce the
4765 boot time on your system, but requires that this
4766 feature is supported by your Linux kernel.
4768 ipaddr - IP address; needed for tftpboot command
4770 loadaddr - Default load address for commands like "bootp",
4771 "rarpboot", "tftpboot", "loadb" or "diskboot"
4773 loads_echo - see CONFIG_LOADS_ECHO
4775 serverip - TFTP server IP address; needed for tftpboot command
4777 bootretry - see CONFIG_BOOT_RETRY_TIME
4779 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4781 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4783 ethprime - controls which interface is used first.
4785 ethact - controls which interface is currently active.
4786 For example you can do the following
4788 => setenv ethact FEC
4789 => ping 192.168.0.1 # traffic sent on FEC
4790 => setenv ethact SCC
4791 => ping 10.0.0.1 # traffic sent on SCC
4793 ethrotate - When set to "no" U-Boot does not go through all
4794 available network interfaces.
4795 It just stays at the currently selected interface.
4797 netretry - When set to "no" each network operation will
4798 either succeed or fail without retrying.
4799 When set to "once" the network operation will
4800 fail when all the available network interfaces
4801 are tried once without success.
4802 Useful on scripts which control the retry operation
4805 npe_ucode - set load address for the NPE microcode
4807 silent_linux - If set then Linux will be told to boot silently, by
4808 changing the console to be empty. If "yes" it will be
4809 made silent. If "no" it will not be made silent. If
4810 unset, then it will be made silent if the U-Boot console
4813 tftpsrcp - If this is set, the value is used for TFTP's
4816 tftpdstp - If this is set, the value is used for TFTP's UDP
4817 destination port instead of the Well Know Port 69.
4819 tftpblocksize - Block size to use for TFTP transfers; if not set,
4820 we use the TFTP server's default block size
4822 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4823 seconds, minimum value is 1000 = 1 second). Defines
4824 when a packet is considered to be lost so it has to
4825 be retransmitted. The default is 5000 = 5 seconds.
4826 Lowering this value may make downloads succeed
4827 faster in networks with high packet loss rates or
4828 with unreliable TFTP servers.
4830 tftptimeoutcountmax - maximum count of TFTP timeouts (no
4831 unit, minimum value = 0). Defines how many timeouts
4832 can happen during a single file transfer before that
4833 transfer is aborted. The default is 10, and 0 means
4834 'no timeouts allowed'. Increasing this value may help
4835 downloads succeed with high packet loss rates, or with
4836 unreliable TFTP servers or client hardware.
4838 vlan - When set to a value < 4095 the traffic over
4839 Ethernet is encapsulated/received over 802.1q
4842 bootpretryperiod - Period during which BOOTP/DHCP sends retries.
4843 Unsigned value, in milliseconds. If not set, the period will
4844 be either the default (28000), or a value based on
4845 CONFIG_NET_RETRY_COUNT, if defined. This value has
4846 precedence over the valu based on CONFIG_NET_RETRY_COUNT.
4848 The following image location variables contain the location of images
4849 used in booting. The "Image" column gives the role of the image and is
4850 not an environment variable name. The other columns are environment
4851 variable names. "File Name" gives the name of the file on a TFTP
4852 server, "RAM Address" gives the location in RAM the image will be
4853 loaded to, and "Flash Location" gives the image's address in NOR
4854 flash or offset in NAND flash.
4856 *Note* - these variables don't have to be defined for all boards, some
4857 boards currently use other variables for these purposes, and some
4858 boards use these variables for other purposes.
4860 Image File Name RAM Address Flash Location
4861 ----- --------- ----------- --------------
4862 u-boot u-boot u-boot_addr_r u-boot_addr
4863 Linux kernel bootfile kernel_addr_r kernel_addr
4864 device tree blob fdtfile fdt_addr_r fdt_addr
4865 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4867 The following environment variables may be used and automatically
4868 updated by the network boot commands ("bootp" and "rarpboot"),
4869 depending the information provided by your boot server:
4871 bootfile - see above
4872 dnsip - IP address of your Domain Name Server
4873 dnsip2 - IP address of your secondary Domain Name Server
4874 gatewayip - IP address of the Gateway (Router) to use
4875 hostname - Target hostname
4877 netmask - Subnet Mask
4878 rootpath - Pathname of the root filesystem on the NFS server
4879 serverip - see above
4882 There are two special Environment Variables:
4884 serial# - contains hardware identification information such
4885 as type string and/or serial number
4886 ethaddr - Ethernet address
4888 These variables can be set only once (usually during manufacturing of
4889 the board). U-Boot refuses to delete or overwrite these variables
4890 once they have been set once.
4893 Further special Environment Variables:
4895 ver - Contains the U-Boot version string as printed
4896 with the "version" command. This variable is
4897 readonly (see CONFIG_VERSION_VARIABLE).
4900 Please note that changes to some configuration parameters may take
4901 only effect after the next boot (yes, that's just like Windoze :-).
4904 Callback functions for environment variables:
4905 ---------------------------------------------
4907 For some environment variables, the behavior of u-boot needs to change
4908 when their values are changed. This functionality allows functions to
4909 be associated with arbitrary variables. On creation, overwrite, or
4910 deletion, the callback will provide the opportunity for some side
4911 effect to happen or for the change to be rejected.
4913 The callbacks are named and associated with a function using the
4914 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4916 These callbacks are associated with variables in one of two ways. The
4917 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4918 in the board configuration to a string that defines a list of
4919 associations. The list must be in the following format:
4921 entry = variable_name[:callback_name]
4924 If the callback name is not specified, then the callback is deleted.
4925 Spaces are also allowed anywhere in the list.
4927 Callbacks can also be associated by defining the ".callbacks" variable
4928 with the same list format above. Any association in ".callbacks" will
4929 override any association in the static list. You can define
4930 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4931 ".callbacks" environment variable in the default or embedded environment.
4933 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
4934 regular expression. This allows multiple variables to be connected to
4935 the same callback without explicitly listing them all out.
4938 Command Line Parsing:
4939 =====================
4941 There are two different command line parsers available with U-Boot:
4942 the old "simple" one, and the much more powerful "hush" shell:
4944 Old, simple command line parser:
4945 --------------------------------
4947 - supports environment variables (through setenv / saveenv commands)
4948 - several commands on one line, separated by ';'
4949 - variable substitution using "... ${name} ..." syntax
4950 - special characters ('$', ';') can be escaped by prefixing with '\',
4952 setenv bootcmd bootm \${address}
4953 - You can also escape text by enclosing in single apostrophes, for example:
4954 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4959 - similar to Bourne shell, with control structures like
4960 if...then...else...fi, for...do...done; while...do...done,
4961 until...do...done, ...
4962 - supports environment ("global") variables (through setenv / saveenv
4963 commands) and local shell variables (through standard shell syntax
4964 "name=value"); only environment variables can be used with "run"
4970 (1) If a command line (or an environment variable executed by a "run"
4971 command) contains several commands separated by semicolon, and
4972 one of these commands fails, then the remaining commands will be
4975 (2) If you execute several variables with one call to run (i. e.
4976 calling run with a list of variables as arguments), any failing
4977 command will cause "run" to terminate, i. e. the remaining
4978 variables are not executed.
4980 Note for Redundant Ethernet Interfaces:
4981 =======================================
4983 Some boards come with redundant Ethernet interfaces; U-Boot supports
4984 such configurations and is capable of automatic selection of a
4985 "working" interface when needed. MAC assignment works as follows:
4987 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4988 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4989 "eth1addr" (=>eth1), "eth2addr", ...
4991 If the network interface stores some valid MAC address (for instance
4992 in SROM), this is used as default address if there is NO correspon-
4993 ding setting in the environment; if the corresponding environment
4994 variable is set, this overrides the settings in the card; that means:
4996 o If the SROM has a valid MAC address, and there is no address in the
4997 environment, the SROM's address is used.
4999 o If there is no valid address in the SROM, and a definition in the
5000 environment exists, then the value from the environment variable is
5003 o If both the SROM and the environment contain a MAC address, and
5004 both addresses are the same, this MAC address is used.
5006 o If both the SROM and the environment contain a MAC address, and the
5007 addresses differ, the value from the environment is used and a
5010 o If neither SROM nor the environment contain a MAC address, an error
5011 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
5012 a random, locally-assigned MAC is used.
5014 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5015 will be programmed into hardware as part of the initialization process. This
5016 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5017 The naming convention is as follows:
5018 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5023 U-Boot is capable of booting (and performing other auxiliary operations on)
5024 images in two formats:
5026 New uImage format (FIT)
5027 -----------------------
5029 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5030 to Flattened Device Tree). It allows the use of images with multiple
5031 components (several kernels, ramdisks, etc.), with contents protected by
5032 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5038 Old image format is based on binary files which can be basically anything,
5039 preceded by a special header; see the definitions in include/image.h for
5040 details; basically, the header defines the following image properties:
5042 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5043 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5044 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5045 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5047 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5048 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5049 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5050 * Compression Type (uncompressed, gzip, bzip2)
5056 The header is marked by a special Magic Number, and both the header
5057 and the data portions of the image are secured against corruption by
5064 Although U-Boot should support any OS or standalone application
5065 easily, the main focus has always been on Linux during the design of
5068 U-Boot includes many features that so far have been part of some
5069 special "boot loader" code within the Linux kernel. Also, any
5070 "initrd" images to be used are no longer part of one big Linux image;
5071 instead, kernel and "initrd" are separate images. This implementation
5072 serves several purposes:
5074 - the same features can be used for other OS or standalone
5075 applications (for instance: using compressed images to reduce the
5076 Flash memory footprint)
5078 - it becomes much easier to port new Linux kernel versions because
5079 lots of low-level, hardware dependent stuff are done by U-Boot
5081 - the same Linux kernel image can now be used with different "initrd"
5082 images; of course this also means that different kernel images can
5083 be run with the same "initrd". This makes testing easier (you don't
5084 have to build a new "zImage.initrd" Linux image when you just
5085 change a file in your "initrd"). Also, a field-upgrade of the
5086 software is easier now.
5092 Porting Linux to U-Boot based systems:
5093 ---------------------------------------
5095 U-Boot cannot save you from doing all the necessary modifications to
5096 configure the Linux device drivers for use with your target hardware
5097 (no, we don't intend to provide a full virtual machine interface to
5100 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5102 Just make sure your machine specific header file (for instance
5103 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5104 Information structure as we define in include/asm-<arch>/u-boot.h,
5105 and make sure that your definition of IMAP_ADDR uses the same value
5106 as your U-Boot configuration in CONFIG_SYS_IMMR.
5108 Note that U-Boot now has a driver model, a unified model for drivers.
5109 If you are adding a new driver, plumb it into driver model. If there
5110 is no uclass available, you are encouraged to create one. See
5114 Configuring the Linux kernel:
5115 -----------------------------
5117 No specific requirements for U-Boot. Make sure you have some root
5118 device (initial ramdisk, NFS) for your target system.
5121 Building a Linux Image:
5122 -----------------------
5124 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5125 not used. If you use recent kernel source, a new build target
5126 "uImage" will exist which automatically builds an image usable by
5127 U-Boot. Most older kernels also have support for a "pImage" target,
5128 which was introduced for our predecessor project PPCBoot and uses a
5129 100% compatible format.
5133 make TQM850L_defconfig
5138 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5139 encapsulate a compressed Linux kernel image with header information,
5140 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5142 * build a standard "vmlinux" kernel image (in ELF binary format):
5144 * convert the kernel into a raw binary image:
5146 ${CROSS_COMPILE}-objcopy -O binary \
5147 -R .note -R .comment \
5148 -S vmlinux linux.bin
5150 * compress the binary image:
5154 * package compressed binary image for U-Boot:
5156 mkimage -A ppc -O linux -T kernel -C gzip \
5157 -a 0 -e 0 -n "Linux Kernel Image" \
5158 -d linux.bin.gz uImage
5161 The "mkimage" tool can also be used to create ramdisk images for use
5162 with U-Boot, either separated from the Linux kernel image, or
5163 combined into one file. "mkimage" encapsulates the images with a 64
5164 byte header containing information about target architecture,
5165 operating system, image type, compression method, entry points, time
5166 stamp, CRC32 checksums, etc.
5168 "mkimage" can be called in two ways: to verify existing images and
5169 print the header information, or to build new images.
5171 In the first form (with "-l" option) mkimage lists the information
5172 contained in the header of an existing U-Boot image; this includes
5173 checksum verification:
5175 tools/mkimage -l image
5176 -l ==> list image header information
5178 The second form (with "-d" option) is used to build a U-Boot image
5179 from a "data file" which is used as image payload:
5181 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5182 -n name -d data_file image
5183 -A ==> set architecture to 'arch'
5184 -O ==> set operating system to 'os'
5185 -T ==> set image type to 'type'
5186 -C ==> set compression type 'comp'
5187 -a ==> set load address to 'addr' (hex)
5188 -e ==> set entry point to 'ep' (hex)
5189 -n ==> set image name to 'name'
5190 -d ==> use image data from 'datafile'
5192 Right now, all Linux kernels for PowerPC systems use the same load
5193 address (0x00000000), but the entry point address depends on the
5196 - 2.2.x kernels have the entry point at 0x0000000C,
5197 - 2.3.x and later kernels have the entry point at 0x00000000.
5199 So a typical call to build a U-Boot image would read:
5201 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5202 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5203 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5204 > examples/uImage.TQM850L
5205 Image Name: 2.4.4 kernel for TQM850L
5206 Created: Wed Jul 19 02:34:59 2000
5207 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5208 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5209 Load Address: 0x00000000
5210 Entry Point: 0x00000000
5212 To verify the contents of the image (or check for corruption):
5214 -> tools/mkimage -l examples/uImage.TQM850L
5215 Image Name: 2.4.4 kernel for TQM850L
5216 Created: Wed Jul 19 02:34:59 2000
5217 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5218 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5219 Load Address: 0x00000000
5220 Entry Point: 0x00000000
5222 NOTE: for embedded systems where boot time is critical you can trade
5223 speed for memory and install an UNCOMPRESSED image instead: this
5224 needs more space in Flash, but boots much faster since it does not
5225 need to be uncompressed:
5227 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5228 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5229 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5230 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5231 > examples/uImage.TQM850L-uncompressed
5232 Image Name: 2.4.4 kernel for TQM850L
5233 Created: Wed Jul 19 02:34:59 2000
5234 Image Type: PowerPC Linux Kernel Image (uncompressed)
5235 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5236 Load Address: 0x00000000
5237 Entry Point: 0x00000000
5240 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5241 when your kernel is intended to use an initial ramdisk:
5243 -> tools/mkimage -n 'Simple Ramdisk Image' \
5244 > -A ppc -O linux -T ramdisk -C gzip \
5245 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5246 Image Name: Simple Ramdisk Image
5247 Created: Wed Jan 12 14:01:50 2000
5248 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5249 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5250 Load Address: 0x00000000
5251 Entry Point: 0x00000000
5253 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5254 option performs the converse operation of the mkimage's second form (the "-d"
5255 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5258 tools/dumpimage -i image -T type -p position data_file
5259 -i ==> extract from the 'image' a specific 'data_file'
5260 -T ==> set image type to 'type'
5261 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5264 Installing a Linux Image:
5265 -------------------------
5267 To downloading a U-Boot image over the serial (console) interface,
5268 you must convert the image to S-Record format:
5270 objcopy -I binary -O srec examples/image examples/image.srec
5272 The 'objcopy' does not understand the information in the U-Boot
5273 image header, so the resulting S-Record file will be relative to
5274 address 0x00000000. To load it to a given address, you need to
5275 specify the target address as 'offset' parameter with the 'loads'
5278 Example: install the image to address 0x40100000 (which on the
5279 TQM8xxL is in the first Flash bank):
5281 => erase 40100000 401FFFFF
5287 ## Ready for S-Record download ...
5288 ~>examples/image.srec
5289 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5291 15989 15990 15991 15992
5292 [file transfer complete]
5294 ## Start Addr = 0x00000000
5297 You can check the success of the download using the 'iminfo' command;
5298 this includes a checksum verification so you can be sure no data
5299 corruption happened:
5303 ## Checking Image at 40100000 ...
5304 Image Name: 2.2.13 for initrd on TQM850L
5305 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5306 Data Size: 335725 Bytes = 327 kB = 0 MB
5307 Load Address: 00000000
5308 Entry Point: 0000000c
5309 Verifying Checksum ... OK
5315 The "bootm" command is used to boot an application that is stored in
5316 memory (RAM or Flash). In case of a Linux kernel image, the contents
5317 of the "bootargs" environment variable is passed to the kernel as
5318 parameters. You can check and modify this variable using the
5319 "printenv" and "setenv" commands:
5322 => printenv bootargs
5323 bootargs=root=/dev/ram
5325 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5327 => printenv bootargs
5328 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5331 ## Booting Linux kernel at 40020000 ...
5332 Image Name: 2.2.13 for NFS on TQM850L
5333 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5334 Data Size: 381681 Bytes = 372 kB = 0 MB
5335 Load Address: 00000000
5336 Entry Point: 0000000c
5337 Verifying Checksum ... OK
5338 Uncompressing Kernel Image ... OK
5339 Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:35:17 MEST 2000
5340 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5341 time_init: decrementer frequency = 187500000/60
5342 Calibrating delay loop... 49.77 BogoMIPS
5343 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5346 If you want to boot a Linux kernel with initial RAM disk, you pass
5347 the memory addresses of both the kernel and the initrd image (PPBCOOT
5348 format!) to the "bootm" command:
5350 => imi 40100000 40200000
5352 ## Checking Image at 40100000 ...
5353 Image Name: 2.2.13 for initrd on TQM850L
5354 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5355 Data Size: 335725 Bytes = 327 kB = 0 MB
5356 Load Address: 00000000
5357 Entry Point: 0000000c
5358 Verifying Checksum ... OK
5360 ## Checking Image at 40200000 ...
5361 Image Name: Simple Ramdisk Image
5362 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5363 Data Size: 566530 Bytes = 553 kB = 0 MB
5364 Load Address: 00000000
5365 Entry Point: 00000000
5366 Verifying Checksum ... OK
5368 => bootm 40100000 40200000
5369 ## Booting Linux kernel at 40100000 ...
5370 Image Name: 2.2.13 for initrd on TQM850L
5371 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5372 Data Size: 335725 Bytes = 327 kB = 0 MB
5373 Load Address: 00000000
5374 Entry Point: 0000000c
5375 Verifying Checksum ... OK
5376 Uncompressing Kernel Image ... OK
5377 ## Loading RAMDisk Image at 40200000 ...
5378 Image Name: Simple Ramdisk Image
5379 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5380 Data Size: 566530 Bytes = 553 kB = 0 MB
5381 Load Address: 00000000
5382 Entry Point: 00000000
5383 Verifying Checksum ... OK
5384 Loading Ramdisk ... OK
5385 Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:32:08 MEST 2000
5386 Boot arguments: root=/dev/ram
5387 time_init: decrementer frequency = 187500000/60
5388 Calibrating delay loop... 49.77 BogoMIPS
5390 RAMDISK: Compressed image found at block 0
5391 VFS: Mounted root (ext2 filesystem).
5395 Boot Linux and pass a flat device tree:
5398 First, U-Boot must be compiled with the appropriate defines. See the section
5399 titled "Linux Kernel Interface" above for a more in depth explanation. The
5400 following is an example of how to start a kernel and pass an updated
5406 oft=oftrees/mpc8540ads.dtb
5407 => tftp $oftaddr $oft
5408 Speed: 1000, full duplex
5410 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5411 Filename 'oftrees/mpc8540ads.dtb'.
5412 Load address: 0x300000
5415 Bytes transferred = 4106 (100a hex)
5416 => tftp $loadaddr $bootfile
5417 Speed: 1000, full duplex
5419 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5421 Load address: 0x200000
5422 Loading:############
5424 Bytes transferred = 1029407 (fb51f hex)
5429 => bootm $loadaddr - $oftaddr
5430 ## Booting image at 00200000 ...
5431 Image Name: Linux-2.6.17-dirty
5432 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5433 Data Size: 1029343 Bytes = 1005.2 kB
5434 Load Address: 00000000
5435 Entry Point: 00000000
5436 Verifying Checksum ... OK
5437 Uncompressing Kernel Image ... OK
5438 Booting using flat device tree at 0x300000
5439 Using MPC85xx ADS machine description
5440 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5444 More About U-Boot Image Types:
5445 ------------------------------
5447 U-Boot supports the following image types:
5449 "Standalone Programs" are directly runnable in the environment
5450 provided by U-Boot; it is expected that (if they behave
5451 well) you can continue to work in U-Boot after return from
5452 the Standalone Program.
5453 "OS Kernel Images" are usually images of some Embedded OS which
5454 will take over control completely. Usually these programs
5455 will install their own set of exception handlers, device
5456 drivers, set up the MMU, etc. - this means, that you cannot
5457 expect to re-enter U-Boot except by resetting the CPU.
5458 "RAMDisk Images" are more or less just data blocks, and their
5459 parameters (address, size) are passed to an OS kernel that is
5461 "Multi-File Images" contain several images, typically an OS
5462 (Linux) kernel image and one or more data images like
5463 RAMDisks. This construct is useful for instance when you want
5464 to boot over the network using BOOTP etc., where the boot
5465 server provides just a single image file, but you want to get
5466 for instance an OS kernel and a RAMDisk image.
5468 "Multi-File Images" start with a list of image sizes, each
5469 image size (in bytes) specified by an "uint32_t" in network
5470 byte order. This list is terminated by an "(uint32_t)0".
5471 Immediately after the terminating 0 follow the images, one by
5472 one, all aligned on "uint32_t" boundaries (size rounded up to
5473 a multiple of 4 bytes).
5475 "Firmware Images" are binary images containing firmware (like
5476 U-Boot or FPGA images) which usually will be programmed to
5479 "Script files" are command sequences that will be executed by
5480 U-Boot's command interpreter; this feature is especially
5481 useful when you configure U-Boot to use a real shell (hush)
5482 as command interpreter.
5484 Booting the Linux zImage:
5485 -------------------------
5487 On some platforms, it's possible to boot Linux zImage. This is done
5488 using the "bootz" command. The syntax of "bootz" command is the same
5489 as the syntax of "bootm" command.
5491 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5492 kernel with raw initrd images. The syntax is slightly different, the
5493 address of the initrd must be augmented by it's size, in the following
5494 format: "<initrd addres>:<initrd size>".
5500 One of the features of U-Boot is that you can dynamically load and
5501 run "standalone" applications, which can use some resources of
5502 U-Boot like console I/O functions or interrupt services.
5504 Two simple examples are included with the sources:
5509 'examples/hello_world.c' contains a small "Hello World" Demo
5510 application; it is automatically compiled when you build U-Boot.
5511 It's configured to run at address 0x00040004, so you can play with it
5515 ## Ready for S-Record download ...
5516 ~>examples/hello_world.srec
5517 1 2 3 4 5 6 7 8 9 10 11 ...
5518 [file transfer complete]
5520 ## Start Addr = 0x00040004
5522 => go 40004 Hello World! This is a test.
5523 ## Starting application at 0x00040004 ...
5534 Hit any key to exit ...
5536 ## Application terminated, rc = 0x0
5538 Another example, which demonstrates how to register a CPM interrupt
5539 handler with the U-Boot code, can be found in 'examples/timer.c'.
5540 Here, a CPM timer is set up to generate an interrupt every second.
5541 The interrupt service routine is trivial, just printing a '.'
5542 character, but this is just a demo program. The application can be
5543 controlled by the following keys:
5545 ? - print current values og the CPM Timer registers
5546 b - enable interrupts and start timer
5547 e - stop timer and disable interrupts
5548 q - quit application
5551 ## Ready for S-Record download ...
5552 ~>examples/timer.srec
5553 1 2 3 4 5 6 7 8 9 10 11 ...
5554 [file transfer complete]
5556 ## Start Addr = 0x00040004
5559 ## Starting application at 0x00040004 ...
5562 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5565 [q, b, e, ?] Set interval 1000000 us
5568 [q, b, e, ?] ........
5569 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5572 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5575 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5578 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5580 [q, b, e, ?] ...Stopping timer
5582 [q, b, e, ?] ## Application terminated, rc = 0x0
5588 Over time, many people have reported problems when trying to use the
5589 "minicom" terminal emulation program for serial download. I (wd)
5590 consider minicom to be broken, and recommend not to use it. Under
5591 Unix, I recommend to use C-Kermit for general purpose use (and
5592 especially for kermit binary protocol download ("loadb" command), and
5593 use "cu" for S-Record download ("loads" command). See
5594 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5595 for help with kermit.
5598 Nevertheless, if you absolutely want to use it try adding this
5599 configuration to your "File transfer protocols" section:
5601 Name Program Name U/D FullScr IO-Red. Multi
5602 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5603 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5609 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5610 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5612 Building requires a cross environment; it is known to work on
5613 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5614 need gmake since the Makefiles are not compatible with BSD make).
5615 Note that the cross-powerpc package does not install include files;
5616 attempting to build U-Boot will fail because <machine/ansi.h> is
5617 missing. This file has to be installed and patched manually:
5619 # cd /usr/pkg/cross/powerpc-netbsd/include
5621 # ln -s powerpc machine
5622 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5623 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5625 Native builds *don't* work due to incompatibilities between native
5626 and U-Boot include files.
5628 Booting assumes that (the first part of) the image booted is a
5629 stage-2 loader which in turn loads and then invokes the kernel
5630 proper. Loader sources will eventually appear in the NetBSD source
5631 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5632 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5635 Implementation Internals:
5636 =========================
5638 The following is not intended to be a complete description of every
5639 implementation detail. However, it should help to understand the
5640 inner workings of U-Boot and make it easier to port it to custom
5644 Initial Stack, Global Data:
5645 ---------------------------
5647 The implementation of U-Boot is complicated by the fact that U-Boot
5648 starts running out of ROM (flash memory), usually without access to
5649 system RAM (because the memory controller is not initialized yet).
5650 This means that we don't have writable Data or BSS segments, and BSS
5651 is not initialized as zero. To be able to get a C environment working
5652 at all, we have to allocate at least a minimal stack. Implementation
5653 options for this are defined and restricted by the CPU used: Some CPU
5654 models provide on-chip memory (like the IMMR area on MPC8xx and
5655 MPC826x processors), on others (parts of) the data cache can be
5656 locked as (mis-) used as memory, etc.
5658 Chris Hallinan posted a good summary of these issues to the
5659 U-Boot mailing list:
5661 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5662 From: "Chris Hallinan" <clh@net1plus.com>
5663 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5666 Correct me if I'm wrong, folks, but the way I understand it
5667 is this: Using DCACHE as initial RAM for Stack, etc, does not
5668 require any physical RAM backing up the cache. The cleverness
5669 is that the cache is being used as a temporary supply of
5670 necessary storage before the SDRAM controller is setup. It's
5671 beyond the scope of this list to explain the details, but you
5672 can see how this works by studying the cache architecture and
5673 operation in the architecture and processor-specific manuals.
5675 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5676 is another option for the system designer to use as an
5677 initial stack/RAM area prior to SDRAM being available. Either
5678 option should work for you. Using CS 4 should be fine if your
5679 board designers haven't used it for something that would
5680 cause you grief during the initial boot! It is frequently not
5683 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5684 with your processor/board/system design. The default value
5685 you will find in any recent u-boot distribution in
5686 walnut.h should work for you. I'd set it to a value larger
5687 than your SDRAM module. If you have a 64MB SDRAM module, set
5688 it above 400_0000. Just make sure your board has no resources
5689 that are supposed to respond to that address! That code in
5690 start.S has been around a while and should work as is when
5691 you get the config right.
5696 It is essential to remember this, since it has some impact on the C
5697 code for the initialization procedures:
5699 * Initialized global data (data segment) is read-only. Do not attempt
5702 * Do not use any uninitialized global data (or implicitly initialized
5703 as zero data - BSS segment) at all - this is undefined, initiali-
5704 zation is performed later (when relocating to RAM).
5706 * Stack space is very limited. Avoid big data buffers or things like
5709 Having only the stack as writable memory limits means we cannot use
5710 normal global data to share information between the code. But it
5711 turned out that the implementation of U-Boot can be greatly
5712 simplified by making a global data structure (gd_t) available to all
5713 functions. We could pass a pointer to this data as argument to _all_
5714 functions, but this would bloat the code. Instead we use a feature of
5715 the GCC compiler (Global Register Variables) to share the data: we
5716 place a pointer (gd) to the global data into a register which we
5717 reserve for this purpose.
5719 When choosing a register for such a purpose we are restricted by the
5720 relevant (E)ABI specifications for the current architecture, and by
5721 GCC's implementation.
5723 For PowerPC, the following registers have specific use:
5725 R2: reserved for system use
5726 R3-R4: parameter passing and return values
5727 R5-R10: parameter passing
5728 R13: small data area pointer
5732 (U-Boot also uses R12 as internal GOT pointer. r12
5733 is a volatile register so r12 needs to be reset when
5734 going back and forth between asm and C)
5736 ==> U-Boot will use R2 to hold a pointer to the global data
5738 Note: on PPC, we could use a static initializer (since the
5739 address of the global data structure is known at compile time),
5740 but it turned out that reserving a register results in somewhat
5741 smaller code - although the code savings are not that big (on
5742 average for all boards 752 bytes for the whole U-Boot image,
5743 624 text + 127 data).
5745 On ARM, the following registers are used:
5747 R0: function argument word/integer result
5748 R1-R3: function argument word
5749 R9: platform specific
5750 R10: stack limit (used only if stack checking is enabled)
5751 R11: argument (frame) pointer
5752 R12: temporary workspace
5755 R15: program counter
5757 ==> U-Boot will use R9 to hold a pointer to the global data
5759 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
5761 On Nios II, the ABI is documented here:
5762 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5764 ==> U-Boot will use gp to hold a pointer to the global data
5766 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5767 to access small data sections, so gp is free.
5769 On NDS32, the following registers are used:
5771 R0-R1: argument/return
5773 R15: temporary register for assembler
5774 R16: trampoline register
5775 R28: frame pointer (FP)
5776 R29: global pointer (GP)
5777 R30: link register (LP)
5778 R31: stack pointer (SP)
5779 PC: program counter (PC)
5781 ==> U-Boot will use R10 to hold a pointer to the global data
5783 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5784 or current versions of GCC may "optimize" the code too much.
5789 U-Boot runs in system state and uses physical addresses, i.e. the
5790 MMU is not used either for address mapping nor for memory protection.
5792 The available memory is mapped to fixed addresses using the memory
5793 controller. In this process, a contiguous block is formed for each
5794 memory type (Flash, SDRAM, SRAM), even when it consists of several
5795 physical memory banks.
5797 U-Boot is installed in the first 128 kB of the first Flash bank (on
5798 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5799 booting and sizing and initializing DRAM, the code relocates itself
5800 to the upper end of DRAM. Immediately below the U-Boot code some
5801 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5802 configuration setting]. Below that, a structure with global Board
5803 Info data is placed, followed by the stack (growing downward).
5805 Additionally, some exception handler code is copied to the low 8 kB
5806 of DRAM (0x00000000 ... 0x00001FFF).
5808 So a typical memory configuration with 16 MB of DRAM could look like
5811 0x0000 0000 Exception Vector code
5814 0x0000 2000 Free for Application Use
5820 0x00FB FF20 Monitor Stack (Growing downward)
5821 0x00FB FFAC Board Info Data and permanent copy of global data
5822 0x00FC 0000 Malloc Arena
5825 0x00FE 0000 RAM Copy of Monitor Code
5826 ... eventually: LCD or video framebuffer
5827 ... eventually: pRAM (Protected RAM - unchanged by reset)
5828 0x00FF FFFF [End of RAM]
5831 System Initialization:
5832 ----------------------
5834 In the reset configuration, U-Boot starts at the reset entry point
5835 (on most PowerPC systems at address 0x00000100). Because of the reset
5836 configuration for CS0# this is a mirror of the on board Flash memory.
5837 To be able to re-map memory U-Boot then jumps to its link address.
5838 To be able to implement the initialization code in C, a (small!)
5839 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5840 which provide such a feature like MPC8xx or MPC8260), or in a locked
5841 part of the data cache. After that, U-Boot initializes the CPU core,
5842 the caches and the SIU.
5844 Next, all (potentially) available memory banks are mapped using a
5845 preliminary mapping. For example, we put them on 512 MB boundaries
5846 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5847 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5848 programmed for SDRAM access. Using the temporary configuration, a
5849 simple memory test is run that determines the size of the SDRAM
5852 When there is more than one SDRAM bank, and the banks are of
5853 different size, the largest is mapped first. For equal size, the first
5854 bank (CS2#) is mapped first. The first mapping is always for address
5855 0x00000000, with any additional banks following immediately to create
5856 contiguous memory starting from 0.
5858 Then, the monitor installs itself at the upper end of the SDRAM area
5859 and allocates memory for use by malloc() and for the global Board
5860 Info data; also, the exception vector code is copied to the low RAM
5861 pages, and the final stack is set up.
5863 Only after this relocation will you have a "normal" C environment;
5864 until that you are restricted in several ways, mostly because you are
5865 running from ROM, and because the code will have to be relocated to a
5869 U-Boot Porting Guide:
5870 ----------------------
5872 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5876 int main(int argc, char *argv[])
5878 sighandler_t no_more_time;
5880 signal(SIGALRM, no_more_time);
5881 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5883 if (available_money > available_manpower) {
5884 Pay consultant to port U-Boot;
5888 Download latest U-Boot source;
5890 Subscribe to u-boot mailing list;
5893 email("Hi, I am new to U-Boot, how do I get started?");
5896 Read the README file in the top level directory;
5897 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5898 Read applicable doc/*.README;
5899 Read the source, Luke;
5900 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5903 if (available_money > toLocalCurrency ($2500))
5906 Add a lot of aggravation and time;
5908 if (a similar board exists) { /* hopefully... */
5909 cp -a board/<similar> board/<myboard>
5910 cp include/configs/<similar>.h include/configs/<myboard>.h
5912 Create your own board support subdirectory;
5913 Create your own board include/configs/<myboard>.h file;
5915 Edit new board/<myboard> files
5916 Edit new include/configs/<myboard>.h
5921 Add / modify source code;
5925 email("Hi, I am having problems...");
5927 Send patch file to the U-Boot email list;
5928 if (reasonable critiques)
5929 Incorporate improvements from email list code review;
5931 Defend code as written;
5937 void no_more_time (int sig)
5946 All contributions to U-Boot should conform to the Linux kernel
5947 coding style; see the file "Documentation/CodingStyle" and the script
5948 "scripts/Lindent" in your Linux kernel source directory.
5950 Source files originating from a different project (for example the
5951 MTD subsystem) are generally exempt from these guidelines and are not
5952 reformatted to ease subsequent migration to newer versions of those
5955 Please note that U-Boot is implemented in C (and to some small parts in
5956 Assembler); no C++ is used, so please do not use C++ style comments (//)
5959 Please also stick to the following formatting rules:
5960 - remove any trailing white space
5961 - use TAB characters for indentation and vertical alignment, not spaces
5962 - make sure NOT to use DOS '\r\n' line feeds
5963 - do not add more than 2 consecutive empty lines to source files
5964 - do not add trailing empty lines to source files
5966 Submissions which do not conform to the standards may be returned
5967 with a request to reformat the changes.
5973 Since the number of patches for U-Boot is growing, we need to
5974 establish some rules. Submissions which do not conform to these rules
5975 may be rejected, even when they contain important and valuable stuff.
5977 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5979 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5980 see http://lists.denx.de/mailman/listinfo/u-boot
5982 When you send a patch, please include the following information with
5985 * For bug fixes: a description of the bug and how your patch fixes
5986 this bug. Please try to include a way of demonstrating that the
5987 patch actually fixes something.
5989 * For new features: a description of the feature and your
5992 * A CHANGELOG entry as plaintext (separate from the patch)
5994 * For major contributions, add a MAINTAINERS file with your
5995 information and associated file and directory references.
5997 * When you add support for a new board, don't forget to add a
5998 maintainer e-mail address to the boards.cfg file, too.
6000 * If your patch adds new configuration options, don't forget to
6001 document these in the README file.
6003 * The patch itself. If you are using git (which is *strongly*
6004 recommended) you can easily generate the patch using the
6005 "git format-patch". If you then use "git send-email" to send it to
6006 the U-Boot mailing list, you will avoid most of the common problems
6007 with some other mail clients.
6009 If you cannot use git, use "diff -purN OLD NEW". If your version of
6010 diff does not support these options, then get the latest version of
6013 The current directory when running this command shall be the parent
6014 directory of the U-Boot source tree (i. e. please make sure that
6015 your patch includes sufficient directory information for the
6018 We prefer patches as plain text. MIME attachments are discouraged,
6019 and compressed attachments must not be used.
6021 * If one logical set of modifications affects or creates several
6022 files, all these changes shall be submitted in a SINGLE patch file.
6024 * Changesets that contain different, unrelated modifications shall be
6025 submitted as SEPARATE patches, one patch per changeset.
6030 * Before sending the patch, run the buildman script on your patched
6031 source tree and make sure that no errors or warnings are reported
6032 for any of the boards.
6034 * Keep your modifications to the necessary minimum: A patch
6035 containing several unrelated changes or arbitrary reformats will be
6036 returned with a request to re-formatting / split it.
6038 * If you modify existing code, make sure that your new code does not
6039 add to the memory footprint of the code ;-) Small is beautiful!
6040 When adding new features, these should compile conditionally only
6041 (using #ifdef), and the resulting code with the new feature
6042 disabled must not need more memory than the old code without your
6045 * Remember that there is a size limit of 100 kB per message on the
6046 u-boot mailing list. Bigger patches will be moderated. If they are
6047 reasonable and not too big, they will be acknowledged. But patches
6048 bigger than the size limit should be avoided.
projects / oweals / u-boot.git / blob