1 Binman Entry Documentation
2 ===========================
4 This file describes the entry types supported by binman. These entry types can
5 be placed in an image one by one to build up a final firmware image. It is
6 fairly easy to create new entry types. Just add a new file to the 'etype'
7 directory. You can use the existing entries as examples.
9 Note that some entries are subclasses of others, using and extending their
10 features to produce new behaviours.
14 Entry: blob: Entry containing an arbitrary binary blob
15 ------------------------------------------------------
17 Note: This should not be used by itself. It is normally used as a parent
18 class by other entry types.
20 Properties / Entry arguments:
21 - filename: Filename of file to read into entry
22 - compress: Compression algorithm to use:
24 lz4: Use lz4 compression (via 'lz4' command-line utility)
26 This entry reads data from a file and places it in the entry. The
27 default filename is often specified specified by the subclass. See for
28 example the 'u_boot' entry which provides the filename 'u-boot.bin'.
30 If compression is enabled, an extra 'uncomp-size' property is written to
31 the node (if enabled with -u) which provides the uncompressed size of the
36 Entry: blob-dtb: A blob that holds a device tree
37 ------------------------------------------------
39 This is a blob containing a device tree. The contents of the blob are
40 obtained from the list of available device-tree files, managed by the
45 Entry: blob-named-by-arg: A blob entry which gets its filename property from its subclass
46 -----------------------------------------------------------------------------------------
48 Properties / Entry arguments:
49 - <xxx>-path: Filename containing the contents of this entry (optional,
52 where <xxx> is the blob_fname argument to the constructor.
54 This entry cannot be used directly. Instead, it is used as a parent class
55 for another entry, which defined blob_fname. This parameter is used to
56 set the entry-arg or property containing the filename. The entry-arg or
57 property is in turn used to set the actual filename.
59 See cros_ec_rw for an example of this.
63 Entry: cros-ec-rw: A blob entry which contains a Chromium OS read-write EC image
64 --------------------------------------------------------------------------------
66 Properties / Entry arguments:
67 - cros-ec-rw-path: Filename containing the EC image
69 This entry holds a Chromium OS EC (embedded controller) image, for use in
70 updating the EC on startup via software sync.
74 Entry: files: Entry containing a set of files
75 ---------------------------------------------
77 Properties / Entry arguments:
78 - pattern: Filename pattern to match the files to include
79 - compress: Compression algorithm to use:
81 lz4: Use lz4 compression (via 'lz4' command-line utility)
83 This entry reads a number of files and places each in a separate sub-entry
84 within this entry. To access these you need to enable device-tree updates
85 at run-time so you can obtain the file positions.
89 Entry: fill: An entry which is filled to a particular byte value
90 ----------------------------------------------------------------
92 Properties / Entry arguments:
93 - fill-byte: Byte to use to fill the entry
95 Note that the size property must be set since otherwise this entry does not
96 know how large it should be.
98 You can often achieve the same effect using the pad-byte property of the
99 overall image, in that the space between entries will then be padded with
100 that byte. But this entry is sometimes useful for explicitly setting the
101 byte value of a region.
105 Entry: fmap: An entry which contains an Fmap section
106 ----------------------------------------------------
108 Properties / Entry arguments:
111 FMAP is a simple format used by flashrom, an open-source utility for
112 reading and writing the SPI flash, typically on x86 CPUs. The format
113 provides flashrom with a list of areas, so it knows what it in the flash.
114 It can then read or write just a single area, instead of the whole flash.
116 The format is defined by the flashrom project, in the file lib/fmap.h -
117 see www.flashrom.org/Flashrom for more information.
119 When used, this entry will be populated with an FMAP which reflects the
120 entries in the current image. Note that any hierarchy is squashed, since
121 FMAP does not support this.
125 Entry: gbb: An entry which contains a Chromium OS Google Binary Block
126 ---------------------------------------------------------------------
128 Properties / Entry arguments:
129 - hardware-id: Hardware ID to use for this build (a string)
130 - keydir: Directory containing the public keys to use
131 - bmpblk: Filename containing images used by recovery
133 Chromium OS uses a GBB to store various pieces of information, in particular
134 the root and recovery keys that are used to verify the boot process. Some
135 more details are here:
137 https://www.chromium.org/chromium-os/firmware-porting-guide/2-concepts
139 but note that the page dates from 2013 so is quite out of date. See
140 README.chromium for how to obtain the required keys and tools.
144 Entry: intel-cmc: Entry containing an Intel Chipset Micro Code (CMC) file
145 -------------------------------------------------------------------------
147 Properties / Entry arguments:
148 - filename: Filename of file to read into entry
150 This file contains microcode for some devices in a special format. An
151 example filename is 'Microcode/C0_22211.BIN'.
153 See README.x86 for information about x86 binary blobs.
157 Entry: intel-descriptor: Intel flash descriptor block (4KB)
158 -----------------------------------------------------------
160 Properties / Entry arguments:
161 filename: Filename of file containing the descriptor. This is typically
162 a 4KB binary file, sometimes called 'descriptor.bin'
164 This entry is placed at the start of flash and provides information about
165 the SPI flash regions. In particular it provides the base address and
166 size of the ME (Management Engine) region, allowing us to place the ME
167 binary in the right place.
169 With this entry in your image, the position of the 'intel-me' entry will be
170 fixed in the image, which avoids you needed to specify an offset for that
171 region. This is useful, because it is not possible to change the position
172 of the ME region without updating the descriptor.
174 See README.x86 for information about x86 binary blobs.
178 Entry: intel-fsp: Entry containing an Intel Firmware Support Package (FSP) file
179 -------------------------------------------------------------------------------
181 Properties / Entry arguments:
182 - filename: Filename of file to read into entry
184 This file contains binary blobs which are used on some devices to make the
185 platform work. U-Boot executes this code since it is not possible to set up
186 the hardware using U-Boot open-source code. Documentation is typically not
187 available in sufficient detail to allow this.
189 An example filename is 'FSP/QUEENSBAY_FSP_GOLD_001_20-DECEMBER-2013.fd'
191 See README.x86 for information about x86 binary blobs.
195 Entry: intel-me: Entry containing an Intel Management Engine (ME) file
196 ----------------------------------------------------------------------
198 Properties / Entry arguments:
199 - filename: Filename of file to read into entry
201 This file contains code used by the SoC that is required to make it work.
202 The Management Engine is like a background task that runs things that are
203 not clearly documented, but may include keyboard, deplay and network
204 access. For platform that use ME it is not possible to disable it. U-Boot
205 does not directly execute code in the ME binary.
207 A typical filename is 'me.bin'.
209 See README.x86 for information about x86 binary blobs.
213 Entry: intel-mrc: Entry containing an Intel Memory Reference Code (MRC) file
214 ----------------------------------------------------------------------------
216 Properties / Entry arguments:
217 - filename: Filename of file to read into entry
219 This file contains code for setting up the SDRAM on some Intel systems. This
220 is executed by U-Boot when needed early during startup. A typical filename
223 See README.x86 for information about x86 binary blobs.
227 Entry: intel-vbt: Entry containing an Intel Video BIOS Table (VBT) file
228 -----------------------------------------------------------------------
230 Properties / Entry arguments:
231 - filename: Filename of file to read into entry
233 This file contains code that sets up the integrated graphics subsystem on
234 some Intel SoCs. U-Boot executes this when the display is started up.
236 See README.x86 for information about Intel binary blobs.
240 Entry: intel-vga: Entry containing an Intel Video Graphics Adaptor (VGA) file
241 -----------------------------------------------------------------------------
243 Properties / Entry arguments:
244 - filename: Filename of file to read into entry
246 This file contains code that sets up the integrated graphics subsystem on
247 some Intel SoCs. U-Boot executes this when the display is started up.
249 This is similar to the VBT file but in a different format.
251 See README.x86 for information about Intel binary blobs.
255 Entry: powerpc-mpc85xx-bootpg-resetvec: PowerPC mpc85xx bootpg + resetvec code for U-Boot
256 -----------------------------------------------------------------------------------------
258 Properties / Entry arguments:
259 - filename: Filename of u-boot-br.bin (default 'u-boot-br.bin')
261 This enrty is valid for PowerPC mpc85xx cpus. This entry holds
262 'bootpg + resetvec' code for PowerPC mpc85xx CPUs which needs to be
263 placed at offset 'RESET_VECTOR_ADDRESS - 0xffc'.
267 Entry: section: Entry that contains other entries
268 -------------------------------------------------
270 Properties / Entry arguments: (see binman README for more information)
271 - size: Size of section in bytes
272 - align-size: Align size to a particular power of two
273 - pad-before: Add padding before the entry
274 - pad-after: Add padding after the entry
275 - pad-byte: Pad byte to use when padding
276 - sort-by-offset: Reorder the entries by offset
277 - end-at-4gb: Used to build an x86 ROM which ends at 4GB (2^32)
278 - name-prefix: Adds a prefix to the name of every entry in the section
279 when writing out the map
281 A section is an entry which can contain other entries, thus allowing
282 hierarchical images to be created. See 'Sections and hierarchical images'
283 in the binman README for more information.
287 Entry: text: An entry which contains text
288 -----------------------------------------
290 The text can be provided either in the node itself or by a command-line
291 argument. There is a level of indirection to allow multiple text strings
294 Properties / Entry arguments:
295 text-label: The value of this string indicates the property / entry-arg
296 that contains the string to place in the entry
297 <xxx> (actual name is the value of text-label): contains the string to
304 text-label = "message";
309 binman -amessage="this is my message"
311 and binman will insert that string into the entry.
313 It is also possible to put the string directly in the node:
317 text-label = "message";
318 message = "a message directly in the node"
321 The text is not itself nul-terminated. This can be achieved, if required,
322 by setting the size of the entry to something larger than the text.
326 Entry: u-boot: U-Boot flat binary
327 ---------------------------------
329 Properties / Entry arguments:
330 - filename: Filename of u-boot.bin (default 'u-boot.bin')
332 This is the U-Boot binary, containing relocation information to allow it
333 to relocate itself at runtime. The binary typically includes a device tree
334 blob at the end of it. Use u_boot_nodtb if you want to package the device
337 U-Boot can access binman symbols at runtime. See:
339 'Access to binman entry offsets at run time (fdt)'
341 in the binman README for more information.
345 Entry: u-boot-dtb: U-Boot device tree
346 -------------------------------------
348 Properties / Entry arguments:
349 - filename: Filename of u-boot.dtb (default 'u-boot.dtb')
351 This is the U-Boot device tree, containing configuration information for
352 U-Boot. U-Boot needs this to know what devices are present and which drivers
355 Note: This is mostly an internal entry type, used by others. This allows
356 binman to know which entries contain a device tree.
360 Entry: u-boot-dtb-with-ucode: A U-Boot device tree file, with the microcode removed
361 -----------------------------------------------------------------------------------
363 Properties / Entry arguments:
364 - filename: Filename of u-boot.dtb (default 'u-boot.dtb')
366 See Entry_u_boot_ucode for full details of the three entries involved in
367 this process. This entry provides the U-Boot device-tree file, which
368 contains the microcode. If the microcode is not being collated into one
369 place then the offset and size of the microcode is recorded by this entry,
370 for use by u_boot_with_ucode_ptr. If it is being collated, then this
371 entry deletes the microcode from the device tree (to save space) and makes
372 it available to u_boot_ucode.
376 Entry: u-boot-elf: U-Boot ELF image
377 -----------------------------------
379 Properties / Entry arguments:
380 - filename: Filename of u-boot (default 'u-boot')
382 This is the U-Boot ELF image. It does not include a device tree but can be
383 relocated to any address for execution.
387 Entry: u-boot-img: U-Boot legacy image
388 --------------------------------------
390 Properties / Entry arguments:
391 - filename: Filename of u-boot.img (default 'u-boot.img')
393 This is the U-Boot binary as a packaged image, in legacy format. It has a
394 header which allows it to be loaded at the correct address for execution.
396 You should use FIT (Flat Image Tree) instead of the legacy image for new
401 Entry: u-boot-nodtb: U-Boot flat binary without device tree appended
402 --------------------------------------------------------------------
404 Properties / Entry arguments:
405 - filename: Filename of u-boot.bin (default 'u-boot-nodtb.bin')
407 This is the U-Boot binary, containing relocation information to allow it
408 to relocate itself at runtime. It does not include a device tree blob at
409 the end of it so normally cannot work without it. You can add a u_boot_dtb
410 entry after this one, or use a u_boot entry instead (which contains both
411 U-Boot and the device tree).
415 Entry: u-boot-spl: U-Boot SPL binary
416 ------------------------------------
418 Properties / Entry arguments:
419 - filename: Filename of u-boot-spl.bin (default 'spl/u-boot-spl.bin')
421 This is the U-Boot SPL (Secondary Program Loader) binary. This is a small
422 binary which loads before U-Boot proper, typically into on-chip SRAM. It is
423 responsible for locating, loading and jumping to U-Boot. Note that SPL is
424 not relocatable so must be loaded to the correct address in SRAM, or written
425 to run from the correct address if direct flash execution is possible (e.g.
428 SPL can access binman symbols at runtime. See:
430 'Access to binman entry offsets at run time (symbols)'
432 in the binman README for more information.
434 The ELF file 'spl/u-boot-spl' must also be available for this to work, since
435 binman uses that to look up symbols to write into the SPL binary.
439 Entry: u-boot-spl-bss-pad: U-Boot SPL binary padded with a BSS region
440 ---------------------------------------------------------------------
442 Properties / Entry arguments:
445 This is similar to u_boot_spl except that padding is added after the SPL
446 binary to cover the BSS (Block Started by Symbol) region. This region holds
447 the various used by SPL. It is set to 0 by SPL when it starts up. If you
448 want to append data to the SPL image (such as a device tree file), you must
449 pad out the BSS region to avoid the data overlapping with U-Boot variables.
450 This entry is useful in that case. It automatically pads out the entry size
451 to cover both the code, data and BSS.
453 The ELF file 'spl/u-boot-spl' must also be available for this to work, since
454 binman uses that to look up the BSS address.
458 Entry: u-boot-spl-dtb: U-Boot SPL device tree
459 ---------------------------------------------
461 Properties / Entry arguments:
462 - filename: Filename of u-boot.dtb (default 'spl/u-boot-spl.dtb')
464 This is the SPL device tree, containing configuration information for
465 SPL. SPL needs this to know what devices are present and which drivers
470 Entry: u-boot-spl-elf: U-Boot SPL ELF image
471 -------------------------------------------
473 Properties / Entry arguments:
474 - filename: Filename of SPL u-boot (default 'spl/u-boot')
476 This is the U-Boot SPL ELF image. It does not include a device tree but can
477 be relocated to any address for execution.
481 Entry: u-boot-spl-nodtb: SPL binary without device tree appended
482 ----------------------------------------------------------------
484 Properties / Entry arguments:
485 - filename: Filename of spl/u-boot-spl-nodtb.bin (default
486 'spl/u-boot-spl-nodtb.bin')
488 This is the U-Boot SPL binary, It does not include a device tree blob at
489 the end of it so may not be able to work without it, assuming SPL needs
490 a device tree to operation on your platform. You can add a u_boot_spl_dtb
491 entry after this one, or use a u_boot_spl entry instead (which contains
492 both SPL and the device tree).
496 Entry: u-boot-spl-with-ucode-ptr: U-Boot SPL with embedded microcode pointer
497 ----------------------------------------------------------------------------
499 This is used when SPL must set up the microcode for U-Boot.
501 See Entry_u_boot_ucode for full details of the entries involved in this
506 Entry: u-boot-tpl: U-Boot TPL binary
507 ------------------------------------
509 Properties / Entry arguments:
510 - filename: Filename of u-boot-tpl.bin (default 'tpl/u-boot-tpl.bin')
512 This is the U-Boot TPL (Tertiary Program Loader) binary. This is a small
513 binary which loads before SPL, typically into on-chip SRAM. It is
514 responsible for locating, loading and jumping to SPL, the next-stage
515 loader. Note that SPL is not relocatable so must be loaded to the correct
516 address in SRAM, or written to run from the correct address if direct
517 flash execution is possible (e.g. on x86 devices).
519 SPL can access binman symbols at runtime. See:
521 'Access to binman entry offsets at run time (symbols)'
523 in the binman README for more information.
525 The ELF file 'tpl/u-boot-tpl' must also be available for this to work, since
526 binman uses that to look up symbols to write into the TPL binary.
530 Entry: u-boot-tpl-dtb: U-Boot TPL device tree
531 ---------------------------------------------
533 Properties / Entry arguments:
534 - filename: Filename of u-boot.dtb (default 'tpl/u-boot-tpl.dtb')
536 This is the TPL device tree, containing configuration information for
537 TPL. TPL needs this to know what devices are present and which drivers
542 Entry: u-boot-tpl-dtb-with-ucode: U-Boot TPL with embedded microcode pointer
543 ----------------------------------------------------------------------------
545 This is used when TPL must set up the microcode for U-Boot.
547 See Entry_u_boot_ucode for full details of the entries involved in this
552 Entry: u-boot-tpl-with-ucode-ptr: U-Boot TPL with embedded microcode pointer
553 ----------------------------------------------------------------------------
555 See Entry_u_boot_ucode for full details of the entries involved in this
560 Entry: u-boot-ucode: U-Boot microcode block
561 -------------------------------------------
563 Properties / Entry arguments:
566 The contents of this entry are filled in automatically by other entries
567 which must also be in the image.
569 U-Boot on x86 needs a single block of microcode. This is collected from
570 the various microcode update nodes in the device tree. It is also unable
571 to read the microcode from the device tree on platforms that use FSP
572 (Firmware Support Package) binaries, because the API requires that the
573 microcode is supplied before there is any SRAM available to use (i.e.
574 the FSP sets up the SRAM / cache-as-RAM but does so in the call that
575 requires the microcode!). To keep things simple, all x86 platforms handle
576 microcode the same way in U-Boot (even non-FSP platforms). This is that
577 a table is placed at _dt_ucode_base_size containing the base address and
578 size of the microcode. This is either passed to the FSP (for FSP
579 platforms), or used to set up the microcode (for non-FSP platforms).
580 This all happens in the build system since it is the only way to get
581 the microcode into a single blob and accessible without SRAM.
583 There are two cases to handle. If there is only one microcode blob in
584 the device tree, then the ucode pointer it set to point to that. This
585 entry (u-boot-ucode) is empty. If there is more than one update, then
586 this entry holds the concatenation of all updates, and the device tree
587 entry (u-boot-dtb-with-ucode) is updated to remove the microcode. This
588 last step ensures that that the microcode appears in one contiguous
589 block in the image and is not unnecessarily duplicated in the device
590 tree. It is referred to as 'collation' here.
592 Entry types that have a part to play in handling microcode:
594 Entry_u_boot_with_ucode_ptr:
595 Contains u-boot-nodtb.bin (i.e. U-Boot without the device tree).
596 It updates it with the address and size of the microcode so that
597 U-Boot can find it early on start-up.
598 Entry_u_boot_dtb_with_ucode:
599 Contains u-boot.dtb. It stores the microcode in a
600 'self.ucode_data' property, which is then read by this class to
601 obtain the microcode if needed. If collation is performed, it
602 removes the microcode from the device tree.
604 This class. If collation is enabled it reads the microcode from
605 the Entry_u_boot_dtb_with_ucode entry, and uses it as the
606 contents of this entry.
610 Entry: u-boot-with-ucode-ptr: U-Boot with embedded microcode pointer
611 --------------------------------------------------------------------
613 Properties / Entry arguments:
614 - filename: Filename of u-boot-nodtb.dtb (default 'u-boot-nodtb.dtb')
615 - optional-ucode: boolean property to make microcode optional. If the
616 u-boot.bin image does not include microcode, no error will
619 See Entry_u_boot_ucode for full details of the three entries involved in
620 this process. This entry updates U-Boot with the offset and size of the
621 microcode, to allow early x86 boot code to find it without doing anything
622 complicated. Otherwise it is the same as the u_boot entry.
626 Entry: vblock: An entry which contains a Chromium OS verified boot block
627 ------------------------------------------------------------------------
629 Properties / Entry arguments:
630 - keydir: Directory containing the public keys to use
631 - keyblock: Name of the key file to use (inside keydir)
632 - signprivate: Name of provide key file to use (inside keydir)
633 - version: Version number of the vblock (typically 1)
634 - kernelkey: Name of the kernel key to use (inside keydir)
635 - preamble-flags: Value of the vboot preamble flags (typically 0)
638 - input.<unique_name> - input file passed to futility
639 - vblock.<unique_name> - output file generated by futility (which is
640 used as the entry contents)
642 Chromium OS signs the read-write firmware and kernel, writing the signature
643 in this block. This allows U-Boot to verify that the next firmware stage
644 and kernel are genuine.
648 Entry: x86-start16: x86 16-bit start-up code for U-Boot
649 -------------------------------------------------------
651 Properties / Entry arguments:
652 - filename: Filename of u-boot-x86-16bit.bin (default
653 'u-boot-x86-16bit.bin')
655 x86 CPUs start up in 16-bit mode, even if they are 32-bit CPUs. This code
656 must be placed at a particular address. This entry holds that code. It is
657 typically placed at offset CONFIG_SYS_X86_START16. The code is responsible
658 for changing to 32-bit mode and jumping to U-Boot's entry point, which
659 requires 32-bit mode (for 32-bit U-Boot).
661 For 64-bit U-Boot, the 'x86_start16_spl' entry type is used instead.
665 Entry: x86-start16-spl: x86 16-bit start-up code for SPL
666 --------------------------------------------------------
668 Properties / Entry arguments:
669 - filename: Filename of spl/u-boot-x86-16bit-spl.bin (default
670 'spl/u-boot-x86-16bit-spl.bin')
672 x86 CPUs start up in 16-bit mode, even if they are 64-bit CPUs. This code
673 must be placed at a particular address. This entry holds that code. It is
674 typically placed at offset CONFIG_SYS_X86_START16. The code is responsible
675 for changing to 32-bit mode and starting SPL, which in turn changes to
676 64-bit mode and jumps to U-Boot (for 64-bit U-Boot).
678 For 32-bit U-Boot, the 'x86_start16' entry type is used instead.
682 Entry: x86-start16-tpl: x86 16-bit start-up code for TPL
683 --------------------------------------------------------
685 Properties / Entry arguments:
686 - filename: Filename of tpl/u-boot-x86-16bit-tpl.bin (default
687 'tpl/u-boot-x86-16bit-tpl.bin')
689 x86 CPUs start up in 16-bit mode, even if they are 64-bit CPUs. This code
690 must be placed at a particular address. This entry holds that code. It is
691 typically placed at offset CONFIG_SYS_X86_START16. The code is responsible
692 for changing to 32-bit mode and starting TPL, which in turn jumps to SPL.
694 If TPL is not being used, the 'x86_start16_spl or 'x86_start16' entry types