X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=README;h=f7ab78a8bfbc34ecea1bdb9d2d41ce54b48d7d46;hb=409677ec1706c1374f9ce5e1833ae425dd0a9602;hp=2865cd7f0bf49c777fcddcc097e0c22e083df106;hpb=84777634621d13a75ea33c7c2ed1a7a76a609a93;p=oweals%2Fu-boot.git diff --git a/README b/README index 2865cd7f0b..f7ab78a8bf 100644 --- a/README +++ b/README @@ -127,7 +127,7 @@ releases in "stable" maintenance trees. Examples: U-Boot v2009.11 - Release November 2009 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree - U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release + U-Boot v2010.09-rc1 - Release candidate 1 for September 2010 release Directory Hierarchy: @@ -137,7 +137,6 @@ Directory Hierarchy: /arc Files generic to ARC architecture /arm Files generic to ARM architecture /avr32 Files generic to AVR32 architecture - /blackfin Files generic to Analog Devices Blackfin architecture /m68k Files generic to m68k architecture /microblaze Files generic to microblaze architecture /mips Files generic to MIPS architecture @@ -147,7 +146,6 @@ Directory Hierarchy: /powerpc Files generic to PowerPC architecture /sandbox Files generic to HW-independent "sandbox" /sh Files generic to SH architecture - /sparc Files generic to SPARC architecture /x86 Files generic to x86 architecture /api Machine/arch independent API for external apps /board Board dependent files @@ -325,27 +323,6 @@ The following options need to be configured: - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined) Define exactly one, e.g. CONFIG_ATSTK1002 -- CPU Module Type: (if CONFIG_COGENT is defined) - Define exactly one of - CONFIG_CMA286_60_OLD ---- FIXME --- not tested yet: - CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P, - CONFIG_CMA287_23, CONFIG_CMA287_50 - -- Motherboard Type: (if CONFIG_COGENT is defined) - Define exactly one of - CONFIG_CMA101, CONFIG_CMA102 - -- Motherboard I/O Modules: (if CONFIG_COGENT is defined) - Define one or more of - CONFIG_CMA302 - -- Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined) - Define one or more of - CONFIG_LCD_HEARTBEAT - update a character position on - the LCD display every second with - a "rotator" |\-/|\-/ - - Marvell Family Member CONFIG_SYS_MVFS - define it if you want to enable multiple fs option at one time @@ -397,15 +374,6 @@ The following options need to be configured: Defines the string to utilize when trying to match PCIe device tree nodes for the given platform. - CONFIG_SYS_PPC_E500_DEBUG_TLB - - Enables a temporary TLB entry to be used during boot to work - around limitations in e500v1 and e500v2 external debugger - support. This reduces the portions of the boot code where - breakpoints and single stepping do not work. The value of this - symbol should be set to the TLB1 entry to be used for this - purpose. - CONFIG_SYS_FSL_ERRATUM_A004510 Enables a workaround for erratum A004510. If set, @@ -534,6 +502,12 @@ The following options need to be configured: CONFIG_SYS_FSL_IFC_LE Defines the IFC controller register space as Little Endian + CONFIG_SYS_FSL_IFC_CLK_DIV + Defines divider of platform clock(clock input to IFC controller). + + CONFIG_SYS_FSL_LBC_CLK_DIV + Defines divider of platform clock(clock input to eLBC controller). + CONFIG_SYS_FSL_PBL_PBI It enables addition of RCW (Power on reset configuration) in built image. Please refer doc/README.pblimage for more details @@ -616,29 +590,6 @@ The following options need to be configured: Select high exception vectors of the ARM core, e.g., do not clear the V bit of the c1 register of CP15. - CONFIG_SYS_THUMB_BUILD - - Use this flag to build U-Boot using the Thumb instruction - set for ARM architectures. Thumb instruction set provides - better code density. For ARM architectures that support - Thumb2 this flag will result in Thumb2 code generated by - GCC. - - CONFIG_ARM_ERRATA_716044 - CONFIG_ARM_ERRATA_742230 - CONFIG_ARM_ERRATA_743622 - CONFIG_ARM_ERRATA_751472 - CONFIG_ARM_ERRATA_761320 - CONFIG_ARM_ERRATA_773022 - CONFIG_ARM_ERRATA_774769 - CONFIG_ARM_ERRATA_794072 - - If set, the workarounds for these ARM errata are applied early - during U-Boot startup. Note that these options force the - workarounds to be applied; no CPU-type/version detection - exists, unlike the similar options in the Linux kernel. Do not - set these options unless they apply! - COUNTER_FREQUENCY Generic timer clock source frequency. @@ -647,15 +598,6 @@ The following options need to be configured: different from COUNTER_FREQUENCY, and can only be determined at run time. - NOTE: The following can be machine specific errata. These - do have ability to provide rudimentary version and machine - specific checks, but expect no product checks. - CONFIG_ARM_ERRATA_430973 - CONFIG_ARM_ERRATA_454179 - CONFIG_ARM_ERRATA_621766 - CONFIG_ARM_ERRATA_798870 - CONFIG_ARM_ERRATA_801819 - - Tegra SoC options: CONFIG_TEGRA_SUPPORT_NON_SECURE @@ -716,11 +658,6 @@ The following options need to be configured: This causes ft_system_setup() to be called before booting the kernel. - CONFIG_OF_BOOT_CPU - - This define fills in the correct boot CPU in the boot - param header, the default value is zero if undefined. - CONFIG_OF_IDE_FIXUP U-Boot can detect if an IDE device is present or not. @@ -796,59 +733,6 @@ The following options need to be configured: port routines must be defined elsewhere (i.e. serial_init(), serial_getc(), ...) - CONFIG_CFB_CONSOLE - Enables console device for a color framebuffer. Needs following - defines (cf. smiLynxEM, i8042) - VIDEO_FB_LITTLE_ENDIAN graphic memory organisation - (default big endian) - VIDEO_HW_RECTFILL graphic chip supports - rectangle fill - (cf. smiLynxEM) - VIDEO_HW_BITBLT graphic chip supports - bit-blit (cf. smiLynxEM) - VIDEO_VISIBLE_COLS visible pixel columns - (cols=pitch) - VIDEO_VISIBLE_ROWS visible pixel rows - VIDEO_PIXEL_SIZE bytes per pixel - VIDEO_DATA_FORMAT graphic data format - (0-5, cf. cfb_console.c) - VIDEO_FB_ADRS framebuffer address - VIDEO_KBD_INIT_FCT keyboard int fct - (i.e. rx51_kp_init()) - VIDEO_TSTC_FCT test char fct - (i.e. rx51_kp_tstc) - VIDEO_GETC_FCT get char fct - (i.e. rx51_kp_getc) - CONFIG_VIDEO_LOGO display Linux logo in - upper left corner - CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of - linux_logo.h for logo. - Requires CONFIG_VIDEO_LOGO - CONFIG_CONSOLE_EXTRA_INFO - additional board info beside - the logo - CONFIG_HIDE_LOGO_VERSION - do not display bootloader - version string - - When CONFIG_CFB_CONSOLE_ANSI is defined, console will support - a limited number of ANSI escape sequences (cursor control, - erase functions and limited graphics rendition control). - - When CONFIG_CFB_CONSOLE is defined, video console is - default i/o. Serial console can be forced with - environment 'console=serial'. - - When CONFIG_SILENT_CONSOLE is defined, all console - messages (by U-Boot and Linux!) can be silenced with - the "silent" environment variable. See - doc/README.silent for more information. - - CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default - is 0x00. - CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default - is 0xa0. - - Console Baudrate: CONFIG_BAUDRATE - in bps Select one of the baudrates listed in @@ -863,23 +747,6 @@ The following options need to be configured: must be defined, to setup the maximum idle timeout for the SMC. -- Pre-Console Buffer: - Prior to the console being initialised (i.e. serial UART - initialised etc) all console output is silently discarded. - Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to - buffer any console messages prior to the console being - initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ - bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is - a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ - bytes are output before the console is initialised, the - earlier bytes are discarded. - - Note that when printing the buffer a copy is made on the - stack so CONFIG_PRE_CON_BUF_SZ must fit on the stack. - - 'Sane' compilers will generate smaller code if - CONFIG_PRE_CON_BUF_SZ is a power of 2 - - Autoboot Command: CONFIG_BOOTCOMMAND Only needed when CONFIG_BOOTDELAY is enabled; @@ -1323,10 +1190,6 @@ The following options need to be configured: CONFIG_LAN91C96 Support for SMSC's LAN91C96 chips. - CONFIG_LAN91C96_BASE - Define this to hold the physical address - of the LAN91C96's I/O space - CONFIG_LAN91C96_USE_32_BIT Define this to enable 32 bit addressing @@ -1391,7 +1254,7 @@ The following options need to be configured: - PWM Support: CONFIG_PWM_IMX - Support for PWM modul on the imx6. + Support for PWM module on the imx6. - TPM Support: CONFIG_TPM @@ -1511,10 +1374,6 @@ The following options need to be configured: Derive USB clock from external clock "blah" - CONFIG_SYS_USB_EXTC_CLK 0x02 - CONFIG_SYS_USB_BRG_CLK 0xBLAH - Derive USB clock from brgclk - - CONFIG_SYS_USB_BRG_CLK 0x04 - If you have a USB-IF assigned VendorID then you may wish to define your own vendor specific values either in BoardName.h or directly in usbd_vendor_info.h. If you don't define @@ -1570,9 +1429,6 @@ The following options need to be configured: CONFIG_SH_MMCIF_CLK Define the clock frequency for MMCIF - CONFIG_GENERIC_MMC - Enable the generic MMC driver - CONFIG_SUPPORT_EMMC_BOOT Enable some additional features of the eMMC boot partitions. @@ -1677,23 +1533,13 @@ The following options need to be configured: If not defined the default value "mbr" is used. - Journaling Flash filesystem support: - CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE, - CONFIG_JFFS2_NAND_DEV + CONFIG_JFFS2_NAND Define these for a default partition on a NAND device CONFIG_SYS_JFFS2_FIRST_SECTOR, CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS Define these for a default partition on a NOR device - CONFIG_SYS_JFFS_CUSTOM_PART - Define this to create an own partition. You have to provide a - function struct part_info* jffs2_part_info(int part_num) - - If you define only one JFFS2 partition you may also want to - #define CONFIG_SYS_JFFS_SINGLE_PART 1 - to disable the command chpart. This is the default when you - have not defined a custom partition - - FAT(File Allocation Table) filesystem write function support: CONFIG_FAT_WRITE @@ -1703,7 +1549,7 @@ The following options need to be configured: This will also enable the command "fatwrite" enabling the user to write files to FAT. -CBFS (Coreboot Filesystem) support +- CBFS (Coreboot Filesystem) support: CONFIG_CMD_CBFS Define this to enable support for reading from a Coreboot @@ -1728,45 +1574,6 @@ CBFS (Coreboot Filesystem) support instead. - Video support: - CONFIG_VIDEO - - Define this to enable video support (for output to - video). - - CONFIG_VIDEO_CT69000 - - Enable Chips & Technologies 69000 Video chip - - CONFIG_VIDEO_SMI_LYNXEM - Enable Silicon Motion SMI 712/710/810 Video chip. The - video output is selected via environment 'videoout' - (1 = LCD and 2 = CRT). If videoout is undefined, CRT is - assumed. - - For the CT69000 and SMI_LYNXEM drivers, videomode is - selected via environment 'videomode'. Two different ways - are possible: - - "videomode=num" 'num' is a standard LiLo mode numbers. - Following standard modes are supported (* is default): - - Colors 640x480 800x600 1024x768 1152x864 1280x1024 - -------------+--------------------------------------------- - 8 bits | 0x301* 0x303 0x305 0x161 0x307 - 15 bits | 0x310 0x313 0x316 0x162 0x319 - 16 bits | 0x311 0x314 0x317 0x163 0x31A - 24 bits | 0x312 0x315 0x318 ? 0x31B - -------------+--------------------------------------------- - (i.e. setenv videomode 317; saveenv; reset;) - - - "videomode=bootargs" all the video parameters are parsed - from the bootargs. (See drivers/video/videomodes.c) - - - CONFIG_VIDEO_SED13806 - Enable Epson SED13806 driver. This driver supports 8bpp - and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP - or CONFIG_VIDEO_SED13806_16BPP - CONFIG_FSL_DIU_FB Enable the Freescale DIU video driver. Reference boards for SOCs that have a DIU should define this macro to enable DIU @@ -1846,12 +1653,6 @@ CBFS (Coreboot Filesystem) support here, since it is cheaper to change data cache settings on a per-section basis. - CONFIG_CONSOLE_SCROLL_LINES - - When the console need to be scrolled, this is the number of - lines to scroll by. It defaults to 1. Increasing this makes - the console jump but can help speed up operation when scrolling - is slow. CONFIG_LCD_ROTATION @@ -1936,12 +1737,6 @@ CBFS (Coreboot Filesystem) support can be displayed via the splashscreen support or the bmp command. -- Do compressing for memory range: - CONFIG_CMD_ZIP - - If this option is set, it would use zlib deflate method - to compress the specified memory at its best effort. - - Compression support: CONFIG_GZIP @@ -2201,7 +1996,7 @@ CBFS (Coreboot Filesystem) support A byte containing the id of the VLAN. -- Status LED: CONFIG_STATUS_LED +- Status LED: CONFIG_LED_STATUS Several configurations allow to display the current status using a LED. For instance, the LED will blink @@ -2209,15 +2004,15 @@ CBFS (Coreboot Filesystem) support soon as a reply to a BOOTP request was received, and start blinking slow once the Linux kernel is running (supported by a status LED driver in the Linux - kernel). Defining CONFIG_STATUS_LED enables this + kernel). Defining CONFIG_LED_STATUS enables this feature in U-Boot. Additional options: - CONFIG_GPIO_LED + CONFIG_LED_STATUS_GPIO The status LED can be connected to a GPIO pin. In such cases, the gpio_led driver can be used as a - status LED backend implementation. Define CONFIG_GPIO_LED + status LED backend implementation. Define CONFIG_LED_STATUS_GPIO to include the gpio_led driver in the U-Boot binary. CONFIG_GPIO_LED_INVERTED_TABLE @@ -2324,8 +2119,6 @@ CBFS (Coreboot Filesystem) support - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4 - - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5 - - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses - drivers/i2c/omap24xx_i2c.c @@ -2379,10 +2172,7 @@ CBFS (Coreboot Filesystem) support additional defines: CONFIG_SYS_NUM_I2C_BUSES - Hold the number of i2c buses you want to use. If you - don't use/have i2c muxes on your i2c bus, this - is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can - omit this define. + Hold the number of i2c buses you want to use. CONFIG_SYS_I2C_DIRECT_BUS define this, if you don't use i2c muxes on your hardware. @@ -2596,7 +2386,7 @@ CBFS (Coreboot Filesystem) support will skip addresses 0x50 and 0x68 on a board with one I2C bus #define CONFIG_I2C_MULTI_BUS - #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} + #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 @@ -2956,19 +2746,6 @@ CBFS (Coreboot Filesystem) support this is instead controlled by the value of /config/load-environment. -- Parallel Flash support: - CONFIG_SYS_NO_FLASH - - Traditionally U-Boot was run on systems with parallel NOR - flash. This option is used to disable support for parallel NOR - flash. This option should be defined if the board does not have - parallel flash. - - If this option is not defined one of the generic flash drivers - (e.g. CONFIG_FLASH_CFI_DRIVER or CONFIG_ST_SMI) must be - selected or the board must provide an implementation of the - flash API (see include/flash.h). - - DataFlash Support: CONFIG_HAS_DATAFLASH @@ -3090,8 +2867,6 @@ CBFS (Coreboot Filesystem) support CONFIG_AT91SAM9XE enable special bootcounter support on at91sam9xe based boards. - CONFIG_BLACKFIN - enable special bootcounter support on blackfin based boards. CONFIG_SOC_DA8XX enable special bootcounter support on da850 based boards. CONFIG_BOOTCOUNT_RAM @@ -3468,10 +3243,6 @@ FIT uImage format: consider that a completely unreadable NAND block is bad, and thus should be skipped silently. - CONFIG_SPL_ABORT_ON_RAW_IMAGE - When defined, SPL will proceed to another boot method - if the image it has loaded does not have a signature. - CONFIG_SPL_RELOC_STACK Adress of the start of the stack SPL will use after relocation. If unspecified, this is equal to @@ -3502,11 +3273,6 @@ FIT uImage format: CONFIG_SPL_INIT_MINIMAL Arch init code should be built for a very small image - CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR, - CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS, - Address and partition on the MMC to load U-Boot from - when the MMC is being used in raw mode. - CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION Partition on the MMC to load U-Boot from when the MMC is being used in raw mode @@ -3691,21 +3457,6 @@ Configuration Settings: - CONFIG_SYS_BAUDRATE_TABLE: List of legal baudrate settings for this board. -- CONFIG_SYS_CONSOLE_INFO_QUIET - Suppress display of console information at boot. - -- CONFIG_SYS_CONSOLE_IS_IN_ENV - If the board specific function - extern int overwrite_console (void); - returns 1, the stdin, stderr and stdout are switched to the - serial port, else the settings in the environment are used. - -- CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE - Enable the call to overwrite_console(). - -- CONFIG_SYS_CONSOLE_ENV_OVERWRITE - Enable overwrite of previous console environment settings. - - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END: Begin and End addresses of the area used by the simple memory test. @@ -3753,10 +3504,6 @@ Configuration Settings: - CONFIG_SYS_SDRAM_BASE: Physical start address of SDRAM. _Must_ be 0 here. -- CONFIG_SYS_MBIO_BASE: - Physical start address of Motherboard I/O (if using a - Cogent motherboard) - - CONFIG_SYS_FLASH_BASE: Physical start address of Flash memory. @@ -4188,7 +3935,7 @@ to save the current settings. This setting describes a second storage area of CONFIG_ENV_SIZE size used to hold a redundant copy of the environment data, so that there is a valid backup copy in case there is a power failure - during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be + during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be aligned to an erase sector boundary. - CONFIG_ENV_SPI_BUS (optional): @@ -4239,7 +3986,7 @@ but it can not erase, write this NOR flash by SRIO or PCIE interface. This setting describes a second storage area of CONFIG_ENV_SIZE size used to hold a redundant copy of the environment data, so that there is a valid backup copy in case there is a power failure - during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be + during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be aligned to an erase block boundary. - CONFIG_ENV_RANGE (optional): @@ -4298,7 +4045,7 @@ but it can not erase, write this NOR flash by SRIO or PCIE interface. Define this to a string that is the name of the block device. - - FAT_ENV_DEV_AND_PART: + - FAT_ENV_DEVICE_AND_PART: Define this to a string to specify the partition of the device. It can be as following: @@ -4540,7 +4287,7 @@ Low Level (hardware related) configuration options: CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial data is located at the end of the available space (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE - - CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just + GENERATED_GBL_DATA_SIZE), and the initial stack is just below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR + CONFIG_SYS_GBL_DATA_OFFSET) downward. @@ -4599,11 +4346,6 @@ Low Level (hardware related) configuration options: enable SPI microcode relocation patch (MPC8xx); define relocation offset in DPRAM [SCC4] -- CONFIG_SYS_USE_OSCCLK: - Use OSCM clock mode on MBX8xx board. Be careful, - wrong setting might damage your board. Read - doc/README.MBX before setting this variable! - - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) Offset of the bootmode word in DPRAM used by post (Power On Self Tests). This definition overrides @@ -4786,12 +4528,6 @@ Low Level (hardware related) configuration options: addressable memory. This option causes some memory accesses to be mapped through map_sysmem() / unmap_sysmem(). -- CONFIG_USE_ARCH_MEMCPY - CONFIG_USE_ARCH_MEMSET - If these options are used a optimized version of memcpy/memset will - be used if available. These functions may be faster under some - conditions but may increase the binary size. - - CONFIG_X86_RESET_VECTOR If defined, the x86 reset vector code is included. This is not needed when U-Boot is running from Coreboot. @@ -4847,10 +4583,6 @@ within that device. Specifies that QE/FMAN firmware is located on the primary SD/MMC device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. -- CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH - Specifies that QE/FMAN firmware is located on the primary SPI - device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. - - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE Specifies that QE/FMAN firmware is located in the remote (master) memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which @@ -4869,22 +4601,6 @@ within that device. - CONFIG_FSL_MC_ENET Enable the MC driver for Layerscape SoCs. -- CONFIG_SYS_LS_MC_FW_ADDR - The address in the storage device where the firmware is located. The - meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro - is also specified. - -- CONFIG_SYS_LS_MC_FW_LENGTH - The maximum possible size of the firmware. The firmware binary format - has a field that specifies the actual size of the firmware, but it - might not be possible to read any part of the firmware unless some - local storage is allocated to hold the entire firmware first. - -- CONFIG_SYS_LS_MC_FW_IN_NOR - Specifies that MC firmware is located in NOR flash, mapped as - normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the - virtual address in NOR flash. - Freescale Layerscape Debug Server Support: ------------------------------------------- The Freescale Layerscape Debug Server Support supports the loading of @@ -6191,11 +5907,6 @@ For PowerPC, the following registers have specific use: average for all boards 752 bytes for the whole U-Boot image, 624 text + 127 data). -On Blackfin, the normal C ABI (except for P3) is followed as documented here: - http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface - - ==> U-Boot will use P3 to hold a pointer to the global data - On ARM, the following registers are used: R0: function argument word/integer result