1 .. SPDX-License-Identifier: GPL-2.0+
2 .. Copyright (c) 2016 Google, Inc
7 Firmware often consists of several components which must be packaged together.
8 For example, we may have SPL, U-Boot, a device tree and an environment area
9 grouped together and placed in MMC flash. When the system starts, it must be
10 able to find these pieces.
12 Building firmware should be separate from packaging it. Many of the complexities
13 of modern firmware build systems come from trying to do both at once. With
14 binman, you build all the pieces that are needed, using whatever assortment of
15 projects and build systems are needed, then use binman to stitch everything
22 Binman reads your board's device tree and finds a node which describes the
23 required image layout. It uses this to work out what to place where.
25 Binman provides a mechanism for building images, from simple SPL + U-Boot
26 combinations, to more complex arrangements with many parts. It also allows
27 users to inspect images, extract and replace binaries within them, repacking if
34 Apart from basic padding, alignment and positioning features, Binman supports
35 hierarchical images, compression, hashing and dealing with the binary blobs
36 which are a sad trend in open-source firmware at present.
38 Executable binaries can access the location of other binaries in an image by
39 using special linker symbols (zero-overhead but somewhat limited) or by reading
40 the devicetree description of the image.
42 Binman is designed primarily for use with U-Boot and associated binaries such
43 as ARM Trusted Firmware, but it is suitable for use with other projects, such
44 as Zephyr. Binman also provides facilities useful in Chromium OS, such as CBFS,
45 vblocks and and the like.
47 Binman provides a way to process binaries before they are included, by adding a
50 Binman is intended for use with U-Boot but is designed to be general enough
51 to be useful in other image-packaging situations.
57 As mentioned above, packaging of firmware is quite a different task from
58 building the various parts. In many cases the various binaries which go into
59 the image come from separate build systems. For example, ARM Trusted Firmware
60 is used on ARMv8 devices but is not built in the U-Boot tree. If a Linux kernel
61 is included in the firmware image, it is built elsewhere.
63 It is of course possible to add more and more build rules to the U-Boot
64 build system to cover these cases. It can shell out to other Makefiles and
65 build scripts. But it seems better to create a clear divide between building
66 software and packaging it.
68 At present this is handled by manual instructions, different for each board,
69 on how to create images that will boot. By turning these instructions into a
70 standard format, we can support making valid images for any board without
71 manual effort, lots of READMEs, etc.
75 - Each binary can have its own build system and tool chain without creating
76 any dependencies between them
77 - Avoids the need for a single-shot build: individual parts can be updated
78 and brought in as needed
79 - Provides for a standard image description available in the build and at
81 - SoC-specific image-signing tools can be accommodated
82 - Avoids cluttering the U-Boot build system with image-building code
83 - The image description is automatically available at run-time in U-Boot,
84 SPL. It can be made available to other software also
85 - The image description is easily readable (it's a text file in device-tree
86 format) and permits flexible packing of binaries
92 Binman uses the following terms:
94 - image - an output file containing a firmware image
95 - binary - an input binary that goes into the image
101 FIT is U-Boot's official image format. It supports multiple binaries with
102 load / execution addresses, compression. It also supports verification
103 through hashing and RSA signatures.
105 FIT was originally designed to support booting a Linux kernel (with an
106 optional ramdisk) and device tree chosen from various options in the FIT.
107 Now that U-Boot supports configuration via device tree, it is possible to
108 load U-Boot from a FIT, with the device tree chosen by SPL.
110 Binman considers FIT to be one of the binaries it can place in the image.
112 Where possible it is best to put as much as possible in the FIT, with binman
113 used to deal with cases not covered by FIT. Examples include initial
114 execution (since FIT itself does not have an executable header) and dealing
115 with device boundaries, such as the read-only/read-write separation in SPI
118 For U-Boot, binman should not be used to create ad-hoc images in place of
122 Relationship to mkimage
123 -----------------------
125 The mkimage tool provides a means to create a FIT. Traditionally it has
126 needed an image description file: a device tree, like binman, but in a
127 different format. More recently it has started to support a '-f auto' mode
128 which can generate that automatically.
130 More relevant to binman, mkimage also permits creation of many SoC-specific
131 image types. These can be listed by running 'mkimage -T list'. Examples
132 include 'rksd', the Rockchip SD/MMC boot format. The mkimage tool is often
133 called from the U-Boot build system for this reason.
135 Binman considers the output files created by mkimage to be binary blobs
136 which it can place in an image. Binman does not replace the mkimage tool or
137 this purpose. It would be possible in some situations to create a new entry
138 type for the images in mkimage, but this would not add functionality. It
139 seems better to use the mkimage tool to generate binaries and avoid blurring
140 the boundaries between building input files (mkimage) and packaging then
141 into a final image (binman).
147 Example use of binman in U-Boot
148 -------------------------------
150 Binman aims to replace some of the ad-hoc image creation in the U-Boot
153 Consider sunxi. It has the following steps:
155 #. It uses a custom mksunxiboot tool to build an SPL image called
156 sunxi-spl.bin. This should probably move into mkimage.
158 #. It uses mkimage to package U-Boot into a legacy image file (so that it can
159 hold the load and execution address) called u-boot.img.
161 #. It builds a final output image called u-boot-sunxi-with-spl.bin which
162 consists of sunxi-spl.bin, some padding and u-boot.img.
164 Binman is intended to replace the last step. The U-Boot build system builds
165 u-boot.bin and sunxi-spl.bin. Binman can then take over creation of
166 sunxi-spl.bin (by calling mksunxiboot, or hopefully one day mkimage). In any
167 case, it would then create the image from the component parts.
169 This simplifies the U-Boot Makefile somewhat, since various pieces of logic
170 can be replaced by a call to binman.
173 Example use of binman for x86
174 -----------------------------
176 In most cases x86 images have a lot of binary blobs, 'black-box' code
177 provided by Intel which must be run for the platform to work. Typically
178 these blobs are not relocatable and must be placed at fixed areas in the
181 Currently this is handled by ifdtool, which places microcode, FSP, MRC, VGA
182 BIOS, reference code and Intel ME binaries into a u-boot.rom file.
184 Binman is intended to replace all of this, with ifdtool left to handle only
185 the configuration of the Intel-format descriptor.
191 First install prerequisites, e.g::
193 sudo apt-get install python-pyelftools python3-pyelftools lzma-alone \
198 binman build -b <board_name>
200 to build an image for a board. The board name is the same name used when
201 configuring U-Boot (e.g. for sandbox_defconfig the board name is 'sandbox').
202 Binman assumes that the input files for the build are in ../b/<board_name>.
204 Or you can specify this explicitly::
206 binman build -I <build_path>
208 where <build_path> is the build directory containing the output of the U-Boot
211 (Future work will make this more configurable)
213 In either case, binman picks up the device tree file (u-boot.dtb) and looks
214 for its instructions in the 'binman' node.
216 Binman has a few other options which you can see by running 'binman -h'.
219 Enabling binman for a board
220 ---------------------------
222 At present binman is invoked from a rule in the main Makefile. You should be
223 able to enable CONFIG_BINMAN to enable this rule.
225 The output file is typically named image.bin and is located in the output
226 directory. If input files are needed to you add these to INPUTS-y either in the
227 main Makefile or in a config.mk file in your arch subdirectory.
229 Once binman is executed it will pick up its instructions from a device-tree
230 file, typically <soc>-u-boot.dtsi, where <soc> is your CONFIG_SYS_SOC value.
231 You can use other, more specific CONFIG options - see 'Automatic .dtsi
235 Access to binman entry offsets at run time (symbols)
236 ----------------------------------------------------
238 Binman assembles images and determines where each entry is placed in the image.
239 This information may be useful to U-Boot at run time. For example, in SPL it
240 is useful to be able to find the location of U-Boot so that it can be executed
241 when SPL is finished.
243 Binman allows you to declare symbols in the SPL image which are filled in
244 with their correct values during the build. For example::
246 binman_sym_declare(ulong, u_boot_any, image_pos);
248 declares a ulong value which will be assigned to the image-pos of any U-Boot
249 image (u-boot.bin, u-boot.img, u-boot-nodtb.bin) that is present in the image.
250 You can access this value with something like::
252 ulong u_boot_offset = binman_sym(ulong, u_boot_any, image_pos);
254 Thus u_boot_offset will be set to the image-pos of U-Boot in memory, assuming
255 that the whole image has been loaded, or is available in flash. You can then
256 jump to that address to start U-Boot.
258 At present this feature is only supported in SPL and TPL. In principle it is
259 possible to fill in such symbols in U-Boot proper, as well, but a future C
260 library is planned for this instead, to read from the device tree.
262 As well as image-pos, it is possible to read the size of an entry and its
263 offset (which is the start position of the entry within its parent).
265 A small technical note: Binman automatically adds the base address of the image
266 (i.e. __image_copy_start) to the value of the image-pos symbol, so that when the
267 image is loaded to its linked address, the value will be correct and actually
268 point into the image.
270 For example, say SPL is at the start of the image and linked to start at address
271 80108000. If U-Boot's image-pos is 0x8000 then binman will write an image-pos
272 for U-Boot of 80110000 into the SPL binary, since it assumes the image is loaded
273 to 80108000, with SPL at 80108000 and U-Boot at 80110000.
275 For x86 devices (with the end-at-4gb property) this base address is not added
276 since it is assumed that images are XIP and the offsets already include the
280 Access to binman entry offsets at run time (fdt)
281 ------------------------------------------------
283 Binman can update the U-Boot FDT to include the final position and size of
284 each entry in the images it processes. The option to enable this is -u and it
285 causes binman to make sure that the 'offset', 'image-pos' and 'size' properties
286 are set correctly for every entry. Since it is not necessary to specify these in
287 the image definition, binman calculates the final values and writes these to
288 the device tree. These can be used by U-Boot at run-time to find the location
291 Alternatively, an FDT map entry can be used to add a special FDT containing
292 just the information about the image. This is preceded by a magic string so can
293 be located anywhere in the image. An image header (typically at the start or end
294 of the image) can be used to point to the FDT map. See fdtmap and image-header
295 entries for more information.
301 The -m option causes binman to output a .map file for each image that it
302 generates. This shows the offset and size of each entry. For example::
305 00000000 00000028 main-section
306 00000000 00000010 section@0
307 00000000 00000004 u-boot
308 00000010 00000010 section@1
309 00000000 00000004 u-boot
311 This shows a hierarchical image with two sections, each with a single entry. The
312 offsets of the sections are absolute hex byte offsets within the image. The
313 offsets of the entries are relative to their respective sections. The size of
314 each entry is also shown, in bytes (hex). The indentation shows the entries
315 nested inside their sections.
318 Passing command-line arguments to entries
319 -----------------------------------------
321 Sometimes it is useful to pass binman the value of an entry property from the
322 command line. For example some entries need access to files and it is not
323 always convenient to put these filenames in the image definition (device tree).
325 The-a option supports this::
331 <prop> is the property to set
332 <value> is the value to set it to
334 Not all properties can be provided this way. Only some entries support it,
335 typically for filenames.
338 Image description format
339 ========================
341 The binman node is called 'binman'. An example image description is shown
345 filename = "u-boot-sunxi-with-spl.bin";
348 filename = "spl/sunxi-spl.bin";
351 offset = <CONFIG_SPL_PAD_TO>;
356 This requests binman to create an image file called u-boot-sunxi-with-spl.bin
357 consisting of a specially formatted SPL (spl/sunxi-spl.bin, built by the
358 normal U-Boot Makefile), some 0xff padding, and a U-Boot legacy image. The
359 padding comes from the fact that the second binary is placed at
360 CONFIG_SPL_PAD_TO. If that line were omitted then the U-Boot binary would
361 immediately follow the SPL binary.
363 The binman node describes an image. The sub-nodes describe entries in the
364 image. Each entry represents a region within the overall image. The name of
365 the entry (blob, u-boot) tells binman what to put there. For 'blob' we must
366 provide a filename. For 'u-boot', binman knows that this means 'u-boot.bin'.
368 Entries are normally placed into the image sequentially, one after the other.
369 The image size is the total size of all entries. As you can see, you can
370 specify the start offset of an entry using the 'offset' property.
372 Note that due to a device tree requirement, all entries must have a unique
373 name. If you want to put the same binary in the image multiple times, you can
374 use any unique name, with the 'type' property providing the type.
376 The attributes supported for entries are described below.
379 This sets the offset of an entry within the image or section containing
380 it. The first byte of the image is normally at offset 0. If 'offset' is
381 not provided, binman sets it to the end of the previous region, or the
382 start of the image's entry area (normally 0) if there is no previous
386 This sets the alignment of the entry. The entry offset is adjusted
387 so that the entry starts on an aligned boundary within the containing
388 section or image. For example 'align = <16>' means that the entry will
389 start on a 16-byte boundary. This may mean that padding is added before
390 the entry. The padding is part of the containing section but is not
391 included in the entry, meaning that an empty space may be created before
392 the entry starts. Alignment should be a power of 2. If 'align' is not
393 provided, no alignment is performed.
396 This sets the size of the entry. The contents will be padded out to
397 this size. If this is not provided, it will be set to the size of the
401 Padding before the contents of the entry. Normally this is 0, meaning
402 that the contents start at the beginning of the entry. This can be used
403 to offset the entry contents a little. While this does not affect the
404 contents of the entry within binman itself (the padding is performed
405 only when its parent section is assembled), the end result will be that
406 the entry starts with the padding bytes, so may grow. Defaults to 0.
409 Padding after the contents of the entry. Normally this is 0, meaning
410 that the entry ends at the last byte of content (unless adjusted by
411 other properties). This allows room to be created in the image for
412 this entry to expand later. While this does not affect the contents of
413 the entry within binman itself (the padding is performed only when its
414 parent section is assembled), the end result will be that the entry ends
415 with the padding bytes, so may grow. Defaults to 0.
418 This sets the alignment of the entry size. For example, to ensure
419 that the size of an entry is a multiple of 64 bytes, set this to 64.
420 While this does not affect the contents of the entry within binman
421 itself (the padding is performed only when its parent section is
422 assembled), the end result is that the entry ends with the padding
423 bytes, so may grow. If 'align-size' is not provided, no alignment is
427 This sets the alignment of the end of an entry with respect to the
428 containing section. Some entries require that they end on an alignment
429 boundary, regardless of where they start. This does not move the start
430 of the entry, so the contents of the entry will still start at the
431 beginning. But there may be padding at the end. While this does not
432 affect the contents of the entry within binman itself (the padding is
433 performed only when its parent section is assembled), the end result
434 is that the entry ends with the padding bytes, so may grow.
435 If 'align-end' is not provided, no alignment is performed.
438 For 'blob' types this provides the filename containing the binary to
439 put into the entry. If binman knows about the entry type (like
440 u-boot-bin), then there is no need to specify this.
443 Sets the type of an entry. This defaults to the entry name, but it is
444 possible to use any name, and then add (for example) 'type = "u-boot"'
448 Indicates that the offset of this entry should not be set by placing
449 it immediately after the entry before. Instead, is set by another
450 entry which knows where this entry should go. When this boolean
451 property is present, binman will give an error if another entry does
452 not set the offset (with the GetOffsets() method).
455 This cannot be set on entry (or at least it is ignored if it is), but
456 with the -u option, binman will set it to the absolute image position
457 for each entry. This makes it easy to find out exactly where the entry
458 ended up in the image, regardless of parent sections, etc.
461 Expand the size of this entry to fit available space. This space is only
462 limited by the size of the image/section and the position of the next
466 Sets the compression algortihm to use (for blobs only). See the entry
467 documentation for details.
470 Sets the tag of the message to show if this entry is missing. This is
471 used for external blobs. When they are missing it is helpful to show
472 information about what needs to be fixed. See missing-blob-help for the
473 message for each tag.
476 By default binman substitutes entries with expanded versions if available,
477 so that a `u-boot` entry type turns into `u-boot-expanded`, for example. The
478 `--no-expanded` command-line option disables this globally. The
479 `no-expanded` property disables this just for a single entry. Put the
480 `no-expanded` boolean property in the node to select this behaviour.
482 The attributes supported for images and sections are described below. Several
483 are similar to those for entries.
486 Sets the image size in bytes, for example 'size = <0x100000>' for a
490 This is similar to 'offset' in entries, setting the offset of a section
491 within the image or section containing it. The first byte of the section
492 is normally at offset 0. If 'offset' is not provided, binman sets it to
493 the end of the previous region, or the start of the image's entry area
494 (normally 0) if there is no previous region.
497 This sets the alignment of the image size. For example, to ensure
498 that the image ends on a 512-byte boundary, use 'align-size = <512>'.
499 If 'align-size' is not provided, no alignment is performed.
502 This sets the padding before the image entries. The first entry will
503 be positioned after the padding. This defaults to 0.
506 This sets the padding after the image entries. The padding will be
507 placed after the last entry. This defaults to 0.
510 This specifies the pad byte to use when padding in the image. It
511 defaults to 0. To use 0xff, you would add 'pad-byte = <0xff>'.
514 This specifies the image filename. It defaults to 'image.bin'.
517 This causes binman to reorder the entries as needed to make sure they
518 are in increasing positional order. This can be used when your entry
519 order may not match the positional order. A common situation is where
520 the 'offset' properties are set by CONFIG options, so their ordering is
523 This is a boolean property so needs no value. To enable it, add a
524 line 'sort-by-offset;' to your description.
527 Normally only a single image is generated. To create more than one
528 image, put this property in the binman node. For example, this will
529 create image1.bin containing u-boot.bin, and image2.bin containing
530 both spl/u-boot-spl.bin and u-boot.bin::
548 For x86 machines the ROM offsets start just before 4GB and extend
549 up so that the image finished at the 4GB boundary. This boolean
550 option can be enabled to support this. The image size must be
551 provided so that binman knows when the image should start. For an
552 8MB ROM, the offset of the first entry would be 0xfff80000 with
553 this option, instead of 0 without this option.
556 This property specifies the entry offset of the first entry.
558 For PowerPC mpc85xx based CPU, CONFIG_SYS_TEXT_BASE is the entry
559 offset of the first entry. It can be 0xeff40000 or 0xfff40000 for
560 nor flash boot, 0x201000 for sd boot etc.
562 'end-at-4gb' property is not applicable where CONFIG_SYS_TEXT_BASE +
565 Examples of the above options can be found in the tests. See the
566 tools/binman/test directory.
568 It is possible to have the same binary appear multiple times in the image,
569 either by using a unit number suffix (u-boot@0, u-boot@1) or by using a
570 different name for each and specifying the type with the 'type' attribute.
573 Sections and hierachical images
574 -------------------------------
576 Sometimes it is convenient to split an image into several pieces, each of which
577 contains its own set of binaries. An example is a flash device where part of
578 the image is read-only and part is read-write. We can set up sections for each
579 of these, and place binaries in them independently. The image is still produced
580 as a single output file.
582 This feature provides a way of creating hierarchical images. For example here
583 is an example image with two copies of U-Boot. One is read-only (ro), intended
584 to be written only in the factory. Another is read-write (rw), so that it can be
585 upgraded in the field. The sizes are fixed so that the ro/rw boundary is known
586 and can be programmed::
604 This image could be placed into a SPI flash chip, with the protection boundary
607 A few special properties are provided for sections:
610 Indicates that this section is read-only. This has no impact on binman's
611 operation, but his property can be read at run time.
614 This string is prepended to all the names of the binaries in the
615 section. In the example above, the 'u-boot' binaries which actually be
616 renamed to 'ro-u-boot' and 'rw-u-boot'. This can be useful to
617 distinguish binaries with otherwise identical names.
623 Image nodes act like sections but also have a few extra properties:
626 Output filename for the image. This defaults to image.bin (or in the
627 case of multiple images <nodename>.bin where <nodename> is the name of
631 Create an image that can be repacked. With this option it is possible
632 to change anything in the image after it is created, including updating
633 the position and size of image components. By default this is not
634 permitted since it is not possibly to know whether this might violate a
635 constraint in the image description. For example, if a section has to
636 increase in size to hold a larger binary, that might cause the section
637 to fall out of its allow region (e.g. read-only portion of flash).
639 Adding this property causes the original offset and size values in the
640 image description to be stored in the FDT and fdtmap.
646 It is possible to ask binman to hash the contents of an entry and write that
647 value back to the device-tree node. For example::
657 Here, a new 'value' property will be written to the 'hash' node containing
658 the hash of the 'u-boot' entry. Only SHA256 is supported at present. Whole
659 sections can be hased if desired, by adding the 'hash' node to the section.
661 The has value can be chcked at runtime by hashing the data actually read and
662 comparing this has to the value in the device tree.
668 Binman automatically replaces 'u-boot' with an expanded version of that, i.e.
669 'u-boot-expanded'. This means that when you write::
677 type = "u-boot-expanded';
680 which in turn expands to::
692 U-Boot's various phase binaries actually comprise two or three pieces.
693 For example, u-boot.bin has the executable followed by a devicetree.
695 With binman we want to be able to update that devicetree with full image
696 information so that it is accessible to the executable. This is tricky
697 if it is not clear where the devicetree starts.
699 The above feature ensures that the devicetree is clearly separated from the
700 U-Boot executable and can be updated separately by binman as needed. It can be
701 disabled with the --no-expanded flag if required.
703 The same applies for u-boot-spl and u-boot-spl. In those cases, the expansion
704 includes the BSS padding, so for example::
713 type = "u-boot-expanded';
716 which in turn expands to::
731 Of course we should not expand SPL if it has no devicetree. Also if the BSS
732 padding is not needed (because BSS is in RAM as with CONFIG_SPL_SEPARATE_BSS),
733 the 'u-boot-spl-bss-pad' subnode should not be created. The use of the expaned
734 entry type is controlled by the UseExpanded() method. In the SPL case it checks
735 the 'spl-dtb' entry arg, which is 'y' or '1' if SPL has a devicetree.
737 For the BSS case, a 'spl-bss-pad' entry arg controls whether it is present. All
738 entry args are provided by the U-Boot Makefile.
744 Binman support compression for 'blob' entries (those of type 'blob' and
745 derivatives). To enable this for an entry, add a 'compress' property::
748 filename = "datafile";
752 The entry will then contain the compressed data, using the 'lz4' compression
753 algorithm. Currently this is the only one that is supported. The uncompressed
754 size is written to the node in an 'uncomp-size' property, if -u is used.
756 Compression is also supported for sections. In that case the entire section is
757 compressed in one block, including all its contents. This means that accessing
758 an entry from the section required decompressing the entire section. Also, the
759 size of a section indicates the space that it consumes in its parent section
760 (and typically the image). With compression, the section may contain more data,
761 and the uncomp-size property indicates that, as above. The contents of the
762 section is compressed first, before any padding is added. This ensures that the
763 padding itself is not compressed, which would be a waste of time.
766 Automatic .dtsi inclusion
767 -------------------------
769 It is sometimes inconvenient to add a 'binman' node to the .dts file for each
770 board. This can be done by using #include to bring in a common file. Another
771 approach supported by the U-Boot build system is to automatically include
772 a common header. You can then put the binman node (and anything else that is
773 specific to U-Boot, such as u-boot,dm-pre-reloc properies) in that header
776 Binman will search for the following files in arch/<arch>/dts::
778 <dts>-u-boot.dtsi where <dts> is the base name of the .dts file
779 <CONFIG_SYS_SOC>-u-boot.dtsi
780 <CONFIG_SYS_CPU>-u-boot.dtsi
781 <CONFIG_SYS_VENDOR>-u-boot.dtsi
784 U-Boot will only use the first one that it finds. If you need to include a
785 more general file you can do that from the more specific file using #include.
786 If you are having trouble figuring out what is going on, you can uncomment
787 the 'warning' line in scripts/Makefile.lib to see what it has found::
789 # Uncomment for debugging
790 # This shows all the files that were considered and the one that we chose.
791 # u_boot_dtsi_options_debug = $(u_boot_dtsi_options_raw)
797 For details on the various entry types supported by binman and how to use them,
798 see entries.rst which is generated from the source code using:
800 binman entry-docs >tools/binman/entries.rst
814 It is possible to list the entries in an existing firmware image created by
815 binman, provided that there is an 'fdtmap' entry in the image. For example::
817 $ binman ls -i image.bin
818 Name Image-pos Size Entry-type Offset Uncomp-size
819 ----------------------------------------------------------------------
820 main-section c00 section 0
822 section 5fc section 4
824 u-boot 138 4 u-boot 38
825 u-boot-dtb 180 108 u-boot-dtb 80 3b5
826 u-boot-dtb 500 1ff u-boot-dtb 400 3b5
827 fdtmap 6fc 381 fdtmap 6fc
828 image-header bf8 8 image-header bf8
830 This shows the hierarchy of the image, the position, size and type of each
831 entry, the offset of each entry within its parent and the uncompressed size if
832 the entry is compressed.
834 It is also possible to list just some files in an image, e.g.::
836 $ binman ls -i image.bin section/cbfs
837 Name Image-pos Size Entry-type Offset Uncomp-size
838 --------------------------------------------------------------------
840 u-boot 138 4 u-boot 38
841 u-boot-dtb 180 108 u-boot-dtb 80 3b5
845 $ binman ls -i image.bin "*cb*" "*head*"
846 Name Image-pos Size Entry-type Offset Uncomp-size
847 ----------------------------------------------------------------------
849 u-boot 138 4 u-boot 38
850 u-boot-dtb 180 108 u-boot-dtb 80 3b5
851 image-header bf8 8 image-header bf8
854 Extracting files from images
855 ----------------------------
857 You can extract files from an existing firmware image created by binman,
858 provided that there is an 'fdtmap' entry in the image. For example::
860 $ binman extract -i image.bin section/cbfs/u-boot
862 which will write the uncompressed contents of that entry to the file 'u-boot' in
863 the current directory. You can also extract to a particular file, in this case
866 $ binman extract -i image.bin section/cbfs/u-boot -f u-boot.bin
868 It is possible to extract all files into a destination directory, which will
869 put files in subdirectories matching the entry hierarchy::
871 $ binman extract -i image.bin -O outdir
873 or just a selection::
875 $ binman extract -i image.bin "*u-boot*" -O outdir
878 Replacing files in an image
879 ---------------------------
881 You can replace files in an existing firmware image created by binman, provided
882 that there is an 'fdtmap' entry in the image. For example:
884 $ binman replace -i image.bin section/cbfs/u-boot
886 which will write the contents of the file 'u-boot' from the current directory
887 to the that entry, compressing if necessary. If the entry size changes, you must
888 add the 'allow-repack' property to the original image before generating it (see
889 above), otherwise you will get an error.
891 You can also use a particular file, in this case u-boot.bin::
893 $ binman replace -i image.bin section/cbfs/u-boot -f u-boot.bin
895 It is possible to replace all files from a source directory which uses the same
896 hierarchy as the entries::
898 $ binman replace -i image.bin -I indir
900 Files that are missing will generate a warning.
902 You can also replace just a selection of entries::
904 $ binman replace -i image.bin "*u-boot*" -I indir
910 Binman normally operates silently unless there is an error, in which case it
911 just displays the error. The -D/--debug option can be used to create a full
912 backtrace when errors occur. You can use BINMAN_DEBUG=1 when building to select
915 Internally binman logs some output while it is running. This can be displayed
916 by increasing the -v/--verbosity from the default of 1:
920 2: notices (important messages)
921 3: info about major operations
922 4: detailed information about each operation
923 5: debug (all output)
925 You can use BINMAN_VERBOSE=5 (for example) when building to select this.
931 Order of image creation
932 -----------------------
934 Image creation proceeds in the following order, for each entry in the image.
936 1. AddMissingProperties() - binman can add calculated values to the device
937 tree as part of its processing, for example the offset and size of each
938 entry. This method adds any properties associated with this, expanding the
939 device tree as needed. These properties can have placeholder values which are
940 set later by SetCalculatedProperties(). By that stage the size of sections
941 cannot be changed (since it would cause the images to need to be repacked),
942 but the correct values can be inserted.
944 2. ProcessFdt() - process the device tree information as required by the
945 particular entry. This may involve adding or deleting properties. If the
946 processing is complete, this method should return True. If the processing
947 cannot complete because it needs the ProcessFdt() method of another entry to
948 run first, this method should return False, in which case it will be called
951 3. GetEntryContents() - the contents of each entry are obtained, normally by
952 reading from a file. This calls the Entry.ObtainContents() to read the
953 contents. The default version of Entry.ObtainContents() calls
954 Entry.GetDefaultFilename() and then reads that file. So a common mechanism
955 to select a file to read is to override that function in the subclass. The
956 functions must return True when they have read the contents. Binman will
957 retry calling the functions a few times if False is returned, allowing
958 dependencies between the contents of different entries.
960 4. GetEntryOffsets() - calls Entry.GetOffsets() for each entry. This can
961 return a dict containing entries that need updating. The key should be the
962 entry name and the value is a tuple (offset, size). This allows an entry to
963 provide the offset and size for other entries. The default implementation
964 of GetEntryOffsets() returns {}.
966 5. PackEntries() - calls Entry.Pack() which figures out the offset and
967 size of an entry. The 'current' image offset is passed in, and the function
968 returns the offset immediately after the entry being packed. The default
969 implementation of Pack() is usually sufficient.
971 Note: for sections, this also checks that the entries do not overlap, nor extend
972 outside the section. If the section does not have a defined size, the size is
973 set large enough to hold all the entries.
975 6. SetImagePos() - sets the image position of every entry. This is the absolute
976 position 'image-pos', as opposed to 'offset' which is relative to the containing
977 section. This must be done after all offsets are known, which is why it is quite
978 late in the ordering.
980 7. SetCalculatedProperties() - update any calculated properties in the device
981 tree. This sets the correct 'offset' and 'size' vaues, for example.
983 8. ProcessEntryContents() - this calls Entry.ProcessContents() on each entry.
984 The default implementatoin does nothing. This can be overriden to adjust the
985 contents of an entry in some way. For example, it would be possible to create
986 an entry containing a hash of the contents of some other entries. At this
987 stage the offset and size of entries should not be adjusted unless absolutely
988 necessary, since it requires a repack (going back to PackEntries()).
990 9. ResetForPack() - if the ProcessEntryContents() step failed, in that an entry
991 has changed its size, then there is no alternative but to go back to step 5 and
992 try again, repacking the entries with the updated size. ResetForPack() removes
993 the fixed offset/size values added by binman, so that the packing can start from
996 10. WriteSymbols() - write the value of symbols into the U-Boot SPL binary.
997 See 'Access to binman entry offsets at run time' below for a description of
998 what happens in this stage.
1000 11. BuildImage() - builds the image and writes it to a file
1002 12. WriteMap() - writes a text file containing a map of the image. This is the
1009 Binman can make use of external command-line tools to handle processing of
1010 entry contents or to generate entry contents. These tools are executed using
1011 the 'tools' module's Run() method. The tools generally must exist on the PATH,
1012 but the --toolpath option can be used to specify additional search paths to
1013 use. This option can be specified multiple times to add more than one path.
1015 For some compile tools binman will use the versions specified by commonly-used
1016 environment variables like CC and HOSTCC for the C compiler, based on whether
1017 the tool's output will be used for the target or for the host machine. If those
1018 aren't given, it will also try to derive target-specific versions from the
1019 CROSS_COMPILE environment variable during a cross-compilation.
1025 Binman is a critical tool and is designed to be very testable. Entry
1026 implementations target 100% test coverage. Run 'binman test -T' to check this.
1028 To enable Python test coverage on Debian-type distributions (e.g. Ubuntu)::
1030 $ sudo apt-get install python-coverage python3-coverage python-pytest
1036 Binman tries to run tests concurrently. This means that the tests make use of
1037 all available CPUs to run.
1041 $ sudo apt-get install python-subunit python3-subunit
1043 Use '-P 1' to disable this. It is automatically disabled when code coverage is
1044 being used (-T) since they are incompatible.
1050 Sometimes when debugging tests it is useful to keep the input and output
1051 directories so they can be examined later. Use -X or --test-preserve-dirs for
1055 Running tests on non-x86 architectures
1056 --------------------------------------
1058 Binman's tests have been written under the assumption that they'll be run on a
1059 x86-like host and there hasn't been an attempt to make them portable yet.
1060 However, it's possible to run the tests by cross-compiling to x86.
1062 To install an x86 cross-compiler on Debian-type distributions (e.g. Ubuntu)::
1064 $ sudo apt-get install gcc-x86-64-linux-gnu
1066 Then, you can run the tests under cross-compilation::
1068 $ CROSS_COMPILE=x86_64-linux-gnu- binman test -T
1070 You can also use gcc-i686-linux-gnu similar to the above.
1073 Writing new entries and debugging
1074 ---------------------------------
1076 The behaviour of entries is defined by the Entry class. All other entries are
1077 a subclass of this. An important subclass is Entry_blob which takes binary
1078 data from a file and places it in the entry. In fact most entry types are
1079 subclasses of Entry_blob.
1081 Each entry type is a separate file in the tools/binman/etype directory. Each
1082 file contains a class called Entry_<type> where <type> is the entry type.
1083 New entry types can be supported by adding new files in that directory.
1084 These will automatically be detected by binman when needed.
1086 Entry properties are documented in entry.py. The entry subclasses are free
1087 to change the values of properties to support special behaviour. For example,
1088 when Entry_blob loads a file, it sets content_size to the size of the file.
1089 Entry classes can adjust other entries. For example, an entry that knows
1090 where other entries should be positioned can set up those entries' offsets
1091 so they don't need to be set in the binman decription. It can also adjust
1094 Most of the time such essoteric behaviour is not needed, but it can be
1095 essential for complex images.
1097 If you need to specify a particular device-tree compiler to use, you can define
1098 the DTC environment variable. This can be useful when the system dtc is too
1101 To enable a full backtrace and other debugging features in binman, pass
1102 BINMAN_DEBUG=1 to your build::
1104 make qemu-x86_defconfig
1107 To enable verbose logging from binman, base BINMAN_VERBOSE to your build, which
1108 adds a -v<level> option to the call to binman::
1110 make qemu-x86_defconfig
1111 make BINMAN_VERBOSE=5
1117 Binman takes a lot of inspiration from a Chrome OS tool called
1118 'cros_bundle_firmware', which I wrote some years ago. That tool was based on
1119 a reasonably simple and sound design but has expanded greatly over the
1120 years. In particular its handling of x86 images is convoluted.
1122 Quite a few lessons have been learned which are hopefully applied here.
1128 On the face of it, a tool to create firmware images should be fairly simple:
1129 just find all the input binaries and place them at the right place in the
1130 image. The difficulty comes from the wide variety of input types (simple
1131 flat binaries containing code, packaged data with various headers), packing
1132 requirments (alignment, spacing, device boundaries) and other required
1133 features such as hierarchical images.
1135 The design challenge is to make it easy to create simple images, while
1136 allowing the more complex cases to be supported. For example, for most
1137 images we don't much care exactly where each binary ends up, so we should
1138 not have to specify that unnecessarily.
1140 New entry types should aim to provide simple usage where possible. If new
1141 core features are needed, they can be added in the Entry base class.
1149 - Use of-platdata to make the information available to code that is unable
1150 to use device tree (such as a very small SPL image). For now, limited info is
1151 available via linker symbols
1152 - Allow easy building of images by specifying just the board name
1153 - Support building an image for a board (-b) more completely, with a
1154 configurable build directory
1155 - Detect invalid properties in nodes
1156 - Sort the fdtmap by offset
1157 - Output temporary files to a different directory
1160 Simon Glass <sjg@chromium.org>