xref: /openbmc/u-boot/tools/binman/README.entries (revision 0f347a00)
1Binman Entry Documentation
2===========================
3
4This file describes the entry types supported by binman. These entry types can
5be placed in an image one by one to build up a final firmware image. It is
6fairly easy to create new entry types. Just add a new file to the 'etype'
7directory. You can use the existing entries as examples.
8
9Note that some entries are subclasses of others, using and extending their
10features to produce new behaviours.
11
12
13
14Entry: blob: Entry containing an arbitrary binary blob
15------------------------------------------------------
16
17Note: This should not be used by itself. It is normally used as a parent
18class by other entry types.
19
20Properties / Entry arguments:
21    - filename: Filename of file to read into entry
22    - compress: Compression algorithm to use:
23        none: No compression
24        lz4: Use lz4 compression (via 'lz4' command-line utility)
25
26This entry reads data from a file and places it in the entry. The
27default filename is often specified specified by the subclass. See for
28example the 'u_boot' entry which provides the filename 'u-boot.bin'.
29
30If compression is enabled, an extra 'uncomp-size' property is written to
31the node (if enabled with -u) which provides the uncompressed size of the
32data.
33
34
35
36Entry: blob-dtb: A blob that holds a device tree
37------------------------------------------------
38
39This is a blob containing a device tree. The contents of the blob are
40obtained from the list of available device-tree files, managed by the
41'state' module.
42
43
44
45Entry: blob-named-by-arg: A blob entry which gets its filename property from its subclass
46-----------------------------------------------------------------------------------------
47
48Properties / Entry arguments:
49    - <xxx>-path: Filename containing the contents of this entry (optional,
50        defaults to 0)
51
52where <xxx> is the blob_fname argument to the constructor.
53
54This entry cannot be used directly. Instead, it is used as a parent class
55for another entry, which defined blob_fname. This parameter is used to
56set the entry-arg or property containing the filename. The entry-arg or
57property is in turn used to set the actual filename.
58
59See cros_ec_rw for an example of this.
60
61
62
63Entry: cros-ec-rw: A blob entry which contains a Chromium OS read-write EC image
64--------------------------------------------------------------------------------
65
66Properties / Entry arguments:
67    - cros-ec-rw-path: Filename containing the EC image
68
69This entry holds a Chromium OS EC (embedded controller) image, for use in
70updating the EC on startup via software sync.
71
72
73
74Entry: files: Entry containing a set of files
75---------------------------------------------
76
77Properties / Entry arguments:
78    - pattern: Filename pattern to match the files to include
79    - compress: Compression algorithm to use:
80        none: No compression
81        lz4: Use lz4 compression (via 'lz4' command-line utility)
82
83This entry reads a number of files and places each in a separate sub-entry
84within this entry. To access these you need to enable device-tree updates
85at run-time so you can obtain the file positions.
86
87
88
89Entry: fill: An entry which is filled to a particular byte value
90----------------------------------------------------------------
91
92Properties / Entry arguments:
93    - fill-byte: Byte to use to fill the entry
94
95Note that the size property must be set since otherwise this entry does not
96know how large it should be.
97
98You can often achieve the same effect using the pad-byte property of the
99overall image, in that the space between entries will then be padded with
100that byte. But this entry is sometimes useful for explicitly setting the
101byte value of a region.
102
103
104
105Entry: fmap: An entry which contains an Fmap section
106----------------------------------------------------
107
108Properties / Entry arguments:
109    None
110
111FMAP is a simple format used by flashrom, an open-source utility for
112reading and writing the SPI flash, typically on x86 CPUs. The format
113provides flashrom with a list of areas, so it knows what it in the flash.
114It can then read or write just a single area, instead of the whole flash.
115
116The format is defined by the flashrom project, in the file lib/fmap.h -
117see www.flashrom.org/Flashrom for more information.
118
119When used, this entry will be populated with an FMAP which reflects the
120entries in the current image. Note that any hierarchy is squashed, since
121FMAP does not support this.
122
123
124
125Entry: gbb: An entry which contains a Chromium OS Google Binary Block
126---------------------------------------------------------------------
127
128Properties / 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
132
133Chromium OS uses a GBB to store various pieces of information, in particular
134the root and recovery keys that are used to verify the boot process. Some
135more details are here:
136
137    https://www.chromium.org/chromium-os/firmware-porting-guide/2-concepts
138
139but note that the page dates from 2013 so is quite out of date. See
140README.chromium for how to obtain the required keys and tools.
141
142
143
144Entry: intel-cmc: Entry containing an Intel Chipset Micro Code (CMC) file
145-------------------------------------------------------------------------
146
147Properties / Entry arguments:
148    - filename: Filename of file to read into entry
149
150This file contains microcode for some devices in a special format. An
151example filename is 'Microcode/C0_22211.BIN'.
152
153See README.x86 for information about x86 binary blobs.
154
155
156
157Entry: intel-descriptor: Intel flash descriptor block (4KB)
158-----------------------------------------------------------
159
160Properties / Entry arguments:
161    filename: Filename of file containing the descriptor. This is typically
162        a 4KB binary file, sometimes called 'descriptor.bin'
163
164This entry is placed at the start of flash and provides information about
165the SPI flash regions. In particular it provides the base address and
166size of the ME (Management Engine) region, allowing us to place the ME
167binary in the right place.
168
169With this entry in your image, the position of the 'intel-me' entry will be
170fixed in the image, which avoids you needed to specify an offset for that
171region. This is useful, because it is not possible to change the position
172of the ME region without updating the descriptor.
173
174See README.x86 for information about x86 binary blobs.
175
176
177
178Entry: intel-fsp: Entry containing an Intel Firmware Support Package (FSP) file
179-------------------------------------------------------------------------------
180
181Properties / Entry arguments:
182    - filename: Filename of file to read into entry
183
184This file contains binary blobs which are used on some devices to make the
185platform work. U-Boot executes this code since it is not possible to set up
186the hardware using U-Boot open-source code. Documentation is typically not
187available in sufficient detail to allow this.
188
189An example filename is 'FSP/QUEENSBAY_FSP_GOLD_001_20-DECEMBER-2013.fd'
190
191See README.x86 for information about x86 binary blobs.
192
193
194
195Entry: intel-me: Entry containing an Intel Management Engine (ME) file
196----------------------------------------------------------------------
197
198Properties / Entry arguments:
199    - filename: Filename of file to read into entry
200
201This file contains code used by the SoC that is required to make it work.
202The Management Engine is like a background task that runs things that are
203not clearly documented, but may include keyboard, deplay and network
204access. For platform that use ME it is not possible to disable it. U-Boot
205does not directly execute code in the ME binary.
206
207A typical filename is 'me.bin'.
208
209See README.x86 for information about x86 binary blobs.
210
211
212
213Entry: intel-mrc: Entry containing an Intel Memory Reference Code (MRC) file
214----------------------------------------------------------------------------
215
216Properties / Entry arguments:
217    - filename: Filename of file to read into entry
218
219This file contains code for setting up the SDRAM on some Intel systems. This
220is executed by U-Boot when needed early during startup. A typical filename
221is 'mrc.bin'.
222
223See README.x86 for information about x86 binary blobs.
224
225
226
227Entry: intel-vbt: Entry containing an Intel Video BIOS Table (VBT) file
228-----------------------------------------------------------------------
229
230Properties / Entry arguments:
231    - filename: Filename of file to read into entry
232
233This file contains code that sets up the integrated graphics subsystem on
234some Intel SoCs. U-Boot executes this when the display is started up.
235
236See README.x86 for information about Intel binary blobs.
237
238
239
240Entry: intel-vga: Entry containing an Intel Video Graphics Adaptor (VGA) file
241-----------------------------------------------------------------------------
242
243Properties / Entry arguments:
244    - filename: Filename of file to read into entry
245
246This file contains code that sets up the integrated graphics subsystem on
247some Intel SoCs. U-Boot executes this when the display is started up.
248
249This is similar to the VBT file but in a different format.
250
251See README.x86 for information about Intel binary blobs.
252
253
254
255Entry: powerpc-mpc85xx-bootpg-resetvec: PowerPC mpc85xx bootpg + resetvec code for U-Boot
256-----------------------------------------------------------------------------------------
257
258Properties / Entry arguments:
259    - filename: Filename of u-boot-br.bin (default 'u-boot-br.bin')
260
261This enrty is valid for PowerPC mpc85xx cpus. This entry holds
262'bootpg + resetvec' code for PowerPC mpc85xx CPUs which needs to be
263placed at offset 'RESET_VECTOR_ADDRESS - 0xffc'.
264
265
266
267Entry: section: Entry that contains other entries
268-------------------------------------------------
269
270Properties / 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
280
281A section is an entry which can contain other entries, thus allowing
282hierarchical images to be created. See 'Sections and hierarchical images'
283in the binman README for more information.
284
285
286
287Entry: text: An entry which contains text
288-----------------------------------------
289
290The text can be provided either in the node itself or by a command-line
291argument. There is a level of indirection to allow multiple text strings
292and sharing of text.
293
294Properties / 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
298        place in the entry.
299
300Example node:
301
302    text {
303        size = <50>;
304        text-label = "message";
305    };
306
307You can then use:
308
309    binman -amessage="this is my message"
310
311and binman will insert that string into the entry.
312
313It is also possible to put the string directly in the node:
314
315    text {
316        size = <8>;
317        text-label = "message";
318        message = "a message directly in the node"
319    };
320
321The text is not itself nul-terminated. This can be achieved, if required,
322by setting the size of the entry to something larger than the text.
323
324
325
326Entry: u-boot: U-Boot flat binary
327---------------------------------
328
329Properties / Entry arguments:
330    - filename: Filename of u-boot.bin (default 'u-boot.bin')
331
332This is the U-Boot binary, containing relocation information to allow it
333to relocate itself at runtime. The binary typically includes a device tree
334blob at the end of it. Use u_boot_nodtb if you want to package the device
335tree separately.
336
337U-Boot can access binman symbols at runtime. See:
338
339    'Access to binman entry offsets at run time (fdt)'
340
341in the binman README for more information.
342
343
344
345Entry: u-boot-dtb: U-Boot device tree
346-------------------------------------
347
348Properties / Entry arguments:
349    - filename: Filename of u-boot.dtb (default 'u-boot.dtb')
350
351This is the U-Boot device tree, containing configuration information for
352U-Boot. U-Boot needs this to know what devices are present and which drivers
353to activate.
354
355Note: This is mostly an internal entry type, used by others. This allows
356binman to know which entries contain a device tree.
357
358
359
360Entry: u-boot-dtb-with-ucode: A U-Boot device tree file, with the microcode removed
361-----------------------------------------------------------------------------------
362
363Properties / Entry arguments:
364    - filename: Filename of u-boot.dtb (default 'u-boot.dtb')
365
366See Entry_u_boot_ucode for full details of the three entries involved in
367this process. This entry provides the U-Boot device-tree file, which
368contains the microcode. If the microcode is not being collated into one
369place then the offset and size of the microcode is recorded by this entry,
370for use by u_boot_with_ucode_ptr. If it is being collated, then this
371entry deletes the microcode from the device tree (to save space) and makes
372it available to u_boot_ucode.
373
374
375
376Entry: u-boot-elf: U-Boot ELF image
377-----------------------------------
378
379Properties / Entry arguments:
380    - filename: Filename of u-boot (default 'u-boot')
381
382This is the U-Boot ELF image. It does not include a device tree but can be
383relocated to any address for execution.
384
385
386
387Entry: u-boot-img: U-Boot legacy image
388--------------------------------------
389
390Properties / Entry arguments:
391    - filename: Filename of u-boot.img (default 'u-boot.img')
392
393This is the U-Boot binary as a packaged image, in legacy format. It has a
394header which allows it to be loaded at the correct address for execution.
395
396You should use FIT (Flat Image Tree) instead of the legacy image for new
397applications.
398
399
400
401Entry: u-boot-nodtb: U-Boot flat binary without device tree appended
402--------------------------------------------------------------------
403
404Properties / Entry arguments:
405    - filename: Filename of u-boot.bin (default 'u-boot-nodtb.bin')
406
407This is the U-Boot binary, containing relocation information to allow it
408to relocate itself at runtime. It does not include a device tree blob at
409the end of it so normally cannot work without it. You can add a u_boot_dtb
410entry after this one, or use a u_boot entry instead (which contains both
411U-Boot and the device tree).
412
413
414
415Entry: u-boot-spl: U-Boot SPL binary
416------------------------------------
417
418Properties / Entry arguments:
419    - filename: Filename of u-boot-spl.bin (default 'spl/u-boot-spl.bin')
420
421This is the U-Boot SPL (Secondary Program Loader) binary. This is a small
422binary which loads before U-Boot proper, typically into on-chip SRAM. It is
423responsible for locating, loading and jumping to U-Boot. Note that SPL is
424not relocatable so must be loaded to the correct address in SRAM, or written
425to run from the correct address if direct flash execution is possible (e.g.
426on x86 devices).
427
428SPL can access binman symbols at runtime. See:
429
430    'Access to binman entry offsets at run time (symbols)'
431
432in the binman README for more information.
433
434The ELF file 'spl/u-boot-spl' must also be available for this to work, since
435binman uses that to look up symbols to write into the SPL binary.
436
437
438
439Entry: u-boot-spl-bss-pad: U-Boot SPL binary padded with a BSS region
440---------------------------------------------------------------------
441
442Properties / Entry arguments:
443    None
444
445This is similar to u_boot_spl except that padding is added after the SPL
446binary to cover the BSS (Block Started by Symbol) region. This region holds
447the various used by SPL. It is set to 0 by SPL when it starts up. If you
448want to append data to the SPL image (such as a device tree file), you must
449pad out the BSS region to avoid the data overlapping with U-Boot variables.
450This entry is useful in that case. It automatically pads out the entry size
451to cover both the code, data and BSS.
452
453The ELF file 'spl/u-boot-spl' must also be available for this to work, since
454binman uses that to look up the BSS address.
455
456
457
458Entry: u-boot-spl-dtb: U-Boot SPL device tree
459---------------------------------------------
460
461Properties / Entry arguments:
462    - filename: Filename of u-boot.dtb (default 'spl/u-boot-spl.dtb')
463
464This is the SPL device tree, containing configuration information for
465SPL. SPL needs this to know what devices are present and which drivers
466to activate.
467
468
469
470Entry: u-boot-spl-elf: U-Boot SPL ELF image
471-------------------------------------------
472
473Properties / Entry arguments:
474    - filename: Filename of SPL u-boot (default 'spl/u-boot')
475
476This is the U-Boot SPL ELF image. It does not include a device tree but can
477be relocated to any address for execution.
478
479
480
481Entry: u-boot-spl-nodtb: SPL binary without device tree appended
482----------------------------------------------------------------
483
484Properties / Entry arguments:
485    - filename: Filename of spl/u-boot-spl-nodtb.bin (default
486        'spl/u-boot-spl-nodtb.bin')
487
488This is the U-Boot SPL binary, It does not include a device tree blob at
489the end of it so may not be able to work without it, assuming SPL needs
490a device tree to operation on your platform. You can add a u_boot_spl_dtb
491entry after this one, or use a u_boot_spl entry instead (which contains
492both SPL and the device tree).
493
494
495
496Entry: u-boot-spl-with-ucode-ptr: U-Boot SPL with embedded microcode pointer
497----------------------------------------------------------------------------
498
499This is used when SPL must set up the microcode for U-Boot.
500
501See Entry_u_boot_ucode for full details of the entries involved in this
502process.
503
504
505
506Entry: u-boot-tpl: U-Boot TPL binary
507------------------------------------
508
509Properties / Entry arguments:
510    - filename: Filename of u-boot-tpl.bin (default 'tpl/u-boot-tpl.bin')
511
512This is the U-Boot TPL (Tertiary Program Loader) binary. This is a small
513binary which loads before SPL, typically into on-chip SRAM. It is
514responsible for locating, loading and jumping to SPL, the next-stage
515loader. Note that SPL is not relocatable so must be loaded to the correct
516address in SRAM, or written to run from the correct address if direct
517flash execution is possible (e.g. on x86 devices).
518
519SPL can access binman symbols at runtime. See:
520
521    'Access to binman entry offsets at run time (symbols)'
522
523in the binman README for more information.
524
525The ELF file 'tpl/u-boot-tpl' must also be available for this to work, since
526binman uses that to look up symbols to write into the TPL binary.
527
528
529
530Entry: u-boot-tpl-dtb: U-Boot TPL device tree
531---------------------------------------------
532
533Properties / Entry arguments:
534    - filename: Filename of u-boot.dtb (default 'tpl/u-boot-tpl.dtb')
535
536This is the TPL device tree, containing configuration information for
537TPL. TPL needs this to know what devices are present and which drivers
538to activate.
539
540
541
542Entry: u-boot-tpl-dtb-with-ucode: U-Boot TPL with embedded microcode pointer
543----------------------------------------------------------------------------
544
545This is used when TPL must set up the microcode for U-Boot.
546
547See Entry_u_boot_ucode for full details of the entries involved in this
548process.
549
550
551
552Entry: u-boot-tpl-with-ucode-ptr: U-Boot TPL with embedded microcode pointer
553----------------------------------------------------------------------------
554
555See Entry_u_boot_ucode for full details of the entries involved in this
556process.
557
558
559
560Entry: u-boot-ucode: U-Boot microcode block
561-------------------------------------------
562
563Properties / Entry arguments:
564    None
565
566The contents of this entry are filled in automatically by other entries
567which must also be in the image.
568
569U-Boot on x86 needs a single block of microcode. This is collected from
570the various microcode update nodes in the device tree. It is also unable
571to read the microcode from the device tree on platforms that use FSP
572(Firmware Support Package) binaries, because the API requires that the
573microcode is supplied before there is any SRAM available to use (i.e.
574the FSP sets up the SRAM / cache-as-RAM but does so in the call that
575requires the microcode!). To keep things simple, all x86 platforms handle
576microcode the same way in U-Boot (even non-FSP platforms). This is that
577a table is placed at _dt_ucode_base_size containing the base address and
578size of the microcode. This is either passed to the FSP (for FSP
579platforms), or used to set up the microcode (for non-FSP platforms).
580This all happens in the build system since it is the only way to get
581the microcode into a single blob and accessible without SRAM.
582
583There are two cases to handle. If there is only one microcode blob in
584the device tree, then the ucode pointer it set to point to that. This
585entry (u-boot-ucode) is empty. If there is more than one update, then
586this entry holds the concatenation of all updates, and the device tree
587entry (u-boot-dtb-with-ucode) is updated to remove the microcode. This
588last step ensures that that the microcode appears in one contiguous
589block in the image and is not unnecessarily duplicated in the device
590tree. It is referred to as 'collation' here.
591
592Entry types that have a part to play in handling microcode:
593
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.
603    Entry_u_boot_ucode:
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.
607
608
609
610Entry: u-boot-with-ucode-ptr: U-Boot with embedded microcode pointer
611--------------------------------------------------------------------
612
613Properties / 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
617        be generated.
618
619See Entry_u_boot_ucode for full details of the three entries involved in
620this process. This entry updates U-Boot with the offset and size of the
621microcode, to allow early x86 boot code to find it without doing anything
622complicated. Otherwise it is the same as the u_boot entry.
623
624
625
626Entry: vblock: An entry which contains a Chromium OS verified boot block
627------------------------------------------------------------------------
628
629Properties / 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)
636
637Output files:
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)
641
642Chromium OS signs the read-write firmware and kernel, writing the signature
643in this block. This allows U-Boot to verify that the next firmware stage
644and kernel are genuine.
645
646
647
648Entry: x86-start16: x86 16-bit start-up code for U-Boot
649-------------------------------------------------------
650
651Properties / Entry arguments:
652    - filename: Filename of u-boot-x86-16bit.bin (default
653        'u-boot-x86-16bit.bin')
654
655x86 CPUs start up in 16-bit mode, even if they are 32-bit CPUs. This code
656must be placed at a particular address. This entry holds that code. It is
657typically placed at offset CONFIG_SYS_X86_START16. The code is responsible
658for changing to 32-bit mode and jumping to U-Boot's entry point, which
659requires 32-bit mode (for 32-bit U-Boot).
660
661For 64-bit U-Boot, the 'x86_start16_spl' entry type is used instead.
662
663
664
665Entry: x86-start16-spl: x86 16-bit start-up code for SPL
666--------------------------------------------------------
667
668Properties / Entry arguments:
669    - filename: Filename of spl/u-boot-x86-16bit-spl.bin (default
670        'spl/u-boot-x86-16bit-spl.bin')
671
672x86 CPUs start up in 16-bit mode, even if they are 64-bit CPUs. This code
673must be placed at a particular address. This entry holds that code. It is
674typically placed at offset CONFIG_SYS_X86_START16. The code is responsible
675for changing to 32-bit mode and starting SPL, which in turn changes to
67664-bit mode and jumps to U-Boot (for 64-bit U-Boot).
677
678For 32-bit U-Boot, the 'x86_start16' entry type is used instead.
679
680
681
682Entry: x86-start16-tpl: x86 16-bit start-up code for TPL
683--------------------------------------------------------
684
685Properties / Entry arguments:
686    - filename: Filename of tpl/u-boot-x86-16bit-tpl.bin (default
687        'tpl/u-boot-x86-16bit-tpl.bin')
688
689x86 CPUs start up in 16-bit mode, even if they are 64-bit CPUs. This code
690must be placed at a particular address. This entry holds that code. It is
691typically placed at offset CONFIG_SYS_X86_START16. The code is responsible
692for changing to 32-bit mode and starting TPL, which in turn jumps to SPL.
693
694If TPL is not being used, the 'x86_start16_spl or 'x86_start16' entry types
695may be used instead.
696
697
698
699