Hello Simon,

On 29.11.23 18:21, Simon Glass wrote:

Add a script which produces a Flat Image Tree (FIT), a single file containing the built kernel and associated devicetree files. Compression defaults to gzip which gives a good balance of size and performance.

Thanks for working on this. I think it's useful to have the kernel generate a FIT image out of the box. More complex use cases are always free to call mkimage with a custom ITS.

The files compress from about 86MB to 24MB using this approach.

The FIT can be used by bootloaders which support it, such as U-Boot and Linuxboot. It permits automatic selection of the correct devicetree, matching the compatible string of the running board with the closest compatible string in the FIT. There is no need for filenames or other workarounds.

Add a 'make image.fit' build target for arm64, as well.

not that it matters much, but should this maybe called Image.fit as the other Image types are capitalized too?

EFI_ZBOOT_PAYLOAD := Image EFI_ZBOOT_BFD_TARGET := elf64-littleaarch64 EFI_ZBOOT_MACH_TYPE := ARM64 diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index 1a965fe68e01..e1c06ca3c847 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -496,6 +496,19 @@ quiet_cmd_uimage = UIMAGE $@ -a $(UIMAGE_LOADADDR) -e $(UIMAGE_ENTRYADDR) \ -n '$(UIMAGE_NAME)' -d $< $@

Doesn't hardcoding a load address and entry address here defeat the point of having FIT as generic portable image format?

At least barebox will try to place the kernel image at physical address 0 and will exit with an error message if no SDRAM is located at that address. The recommendation in that case is to omit load and entry address altogether to have barebox find a suitable location, but I see now that the FIT specification requires a load and entry address. What would happen if U-Boot tries to load this FIT image on a board that has no DRAM at address 0?

Please Cc me on subsequent revisions. I am interested in testing that this works for barebox too.

Thanks, Ahmad

Simon,

thanks for the patch! Below are some nitpicks and bike-shedding questions.

On Wed 29 Nov 2023 10:21:53 GMT, Simon Glass wrote:

Add a script which produces a Flat Image Tree (FIT), a single file containing the built kernel and associated devicetree files. Compression defaults to gzip which gives a good balance of size and performance.

The files compress from about 86MB to 24MB using this approach.

The FIT can be used by bootloaders which support it, such as U-Boot and Linuxboot. It permits automatic selection of the correct devicetree, matching the compatible string of the running board with the closest compatible string in the FIT. There is no need for filenames or other workarounds.

Have you thought about updating the arch/mips ITB rules to also use the new scripts/make_fit.py? Or is the FIT/ITB format for mips different from the one for arm64?

Add a 'make image.fit' build target for arm64, as well.

The FIT can be examined using 'dumpimage -l'.

This features requires pylibfdt (use 'pip install libfdt'). It also requires compression utilities for the algorithm being used. Supported compression options are the same as the Image.xxx files. For now there is no way to change the compression other than by editing the rule for $(obj)/image.fit

While FIT supports a ramdisk / initrd, no attempt is made to support this here, since it must be built separately from the Linux build.

Signed-off-by: Simon Glass sjg@chromium.org

Changes in v7:

• Add Image as a dependency of image.fit
• Drop kbuild tag
• Add dependency on dtbs
• Drop unnecessary path separator for dtbs
• Rebase to -next

Changes in v5:

• Drop patch previously applied
• Correct compression rule which was broken in v4

Changes in v4:

• Use single quotes for UIMAGE_NAME

Changes in v3:

• Drop temporary file image.itk
• Drop patch 'Use double quotes for image name'
• Drop double quotes in use of UIMAGE_NAME
• Drop unnecessary CONFIG_EFI_ZBOOT condition for help
• Avoid hard-coding "arm64" for the DT architecture

Changes in v2:

• Drop patch previously applied
• Add .gitignore file
• Move fit rule to Makefile.lib using an intermediate file
• Drop dependency on CONFIG_EFI_ZBOOT
• Pick up .dtb files separately from the kernel
• Correct pylint too-many-args warning for write_kernel()
• Include the kernel image in the file count
• Add a pointer to the FIT spec and mention of its wide industry usage
• Mention the kernel version in the FIT description

MAINTAINERS | 7 + arch/arm64/Makefile | 9 +- arch/arm64/boot/.gitignore | 1 + arch/arm64/boot/Makefile | 6 +- scripts/Makefile.lib | 13 ++ scripts/make_fit.py | 289 +++++++++++++++++++++++++++++++++++++ 6 files changed, 322 insertions(+), 3 deletions(-) create mode 100755 scripts/make_fit.py

diff --git a/MAINTAINERS b/MAINTAINERS index 14587be87a33..d609f0e8deb3 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -1585,6 +1585,13 @@ F: Documentation/process/maintainer-soc*.rst F: arch/arm/boot/dts/Makefile F: arch/arm64/boot/dts/Makefile

+ARM64 FIT SUPPORT +M: Simon Glass sjg@chromium.org +L: linux-arm-kernel@lists.infradead.org (moderated for non-subscribers) +S: Maintained +F: arch/arm64/boot/Makefile +F: scripts/make_fit.py

I'm afraid that the location does not match the requested sorting, it should be right before "ARM64 PORT".

ARM ARCHITECTED TIMER DRIVER M: Mark Rutland mark.rutland@arm.com M: Marc Zyngier maz@kernel.org diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile index 1bd4fae6e806..18e092de7cdb 100644 --- a/arch/arm64/Makefile +++ b/arch/arm64/Makefile @@ -36,6 +36,8 @@ ifeq ($(CONFIG_BROKEN_GAS_INST),y) $(warning Detected assembler with broken .inst; disassembly will be unreliable) endif

+KBUILD_DTBS := dtbs

Might you want to use tabs here as in the lines below?

KBUILD_CFLAGS += -mgeneral-regs-only \ $(compat_vdso) $(cc_has_k_constraint) KBUILD_CFLAGS += $(call cc-disable-warning, psabi) @@ -150,7 +152,7 @@ libs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a # Default target when executing plain make boot := arch/arm64/boot

-BOOT_TARGETS := Image vmlinuz.efi +BOOT_TARGETS := Image vmlinuz.efi image.fit

PHONY += $(BOOT_TARGETS)

@@ -162,7 +164,9 @@ endif

all: $(notdir $(KBUILD_IMAGE))

-vmlinuz.efi: Image +image.fit: $(KBUILD_DTBS)

+vmlinuz.efi image.fit: Image $(BOOT_TARGETS): vmlinux $(Q)$(MAKE) $(build)=$(boot) $(boot)/$@

@@ -215,6 +219,7 @@ virtconfig: define archhelp echo '* Image.gz - Compressed kernel image (arch/$(ARCH)/boot/Image.gz)' echo ' Image - Uncompressed kernel image (arch/$(ARCH)/boot/Image)'

• echo ' image.fit - Flat Image Tree (arch/$(ARCH)/boot/image.fit)' echo ' install - Install uncompressed kernel' echo ' zinstall - Install compressed kernel' echo ' Install using (your) ~/bin/installkernel or'

diff --git a/arch/arm64/boot/.gitignore b/arch/arm64/boot/.gitignore index af5dc61f8b43..abaae9de1bdd 100644 --- a/arch/arm64/boot/.gitignore +++ b/arch/arm64/boot/.gitignore @@ -2,3 +2,4 @@ Image Image.gz vmlinuz* +image.fit diff --git a/arch/arm64/boot/Makefile b/arch/arm64/boot/Makefile index 1761f5972443..8d591fda078f 100644 --- a/arch/arm64/boot/Makefile +++ b/arch/arm64/boot/Makefile @@ -16,7 +16,8 @@

OBJCOPYFLAGS_Image :=-O binary -R .note -R .note.gnu.build-id -R .comment -S

-targets := Image Image.bz2 Image.gz Image.lz4 Image.lzma Image.lzo Image.zst +targets := Image Image.bz2 Image.gz Image.lz4 Image.lzma Image.lzo \

• Image.zst image.fit

Do you introduce the first lower-case image.* target by intention? (All others have a capital 'I'.)

$(obj)/Image: vmlinux FORCE $(call if_changed,objcopy) @@ -39,6 +40,9 @@ $(obj)/Image.lzo: $(obj)/Image FORCE $(obj)/Image.zst: $(obj)/Image FORCE $(call if_changed,zstd)

+$(obj)/image.fit: $(obj)/Image FORCE

• $(call cmd,fit,gzip)

EFI_ZBOOT_PAYLOAD := Image EFI_ZBOOT_BFD_TARGET := elf64-littleaarch64 EFI_ZBOOT_MACH_TYPE := ARM64 diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index 1a965fe68e01..e1c06ca3c847 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -496,6 +496,19 @@ quiet_cmd_uimage = UIMAGE $@ -a $(UIMAGE_LOADADDR) -e $(UIMAGE_ENTRYADDR) \ -n '$(UIMAGE_NAME)' -d $< $@

+# Flat Image Tree (FIT) +# This allows for packaging of a kernel and all devicetrees files, using +# compression. +# ---------------------------------------------------------------------------

+MAKE_FIT := $(srctree)/scripts/make_fit.py

+quiet_cmd_fit = FIT $@

•  cmd_fit = $(MAKE_FIT) -f $@ --arch $(UIMAGE_ARCH) --os linux \
  

• 	--name '$(UIMAGE_NAME)' \
  

• 	--compress $(UIMAGE_COMPRESSION) -k $< \
  

• 	$(dir $<)dts
  

Alternatively, you could use '$(<D)/dts' instead of '$(dir $<)dts' (bike-shedding).

# XZ # --------------------------------------------------------------------------- # Use xzkern to compress the kernel image and xzmisc to compress other things. diff --git a/scripts/make_fit.py b/scripts/make_fit.py new file mode 100755 index 000000000000..e1059825de9c --- /dev/null +++ b/scripts/make_fit.py @@ -0,0 +1,289 @@ +#!/usr/bin/env python3 +# SPDX-License-Identifier: GPL-2.0+ +# +# Copyright 2023 Google LLC +# Written by Simon Glass sjg@chromium.org +#

+"""Build a FIT containing a lot of devicetree files

+Usage:

• make_fit.py -A arm64 -n 'Linux-6.6' -O linux

•    -f arch/arm64/boot/image.fit -k /tmp/kern/arch/arm64/boot/image.itk
  

•    /tmp/kern/arch/arm64/boot/dts/ -E -c gzip
  

+Creates a FIT containing the supplied kernel and a directory containing the +devicetree files.

+Use -E to generate an external FIT (where the data is placed after the +FIT data structure). This allows parsing of the data without loading +the entire FIT.

+Use -c to compress the data, using bzip2, gzip, lz4, lzma, lzo and +zstd

Lost a dot at EOL?

+The resulting FIT can be booted by bootloaders which support FIT, such +as U-Boot, Linuxboot, Tianocore, etc.

+Note that this tool does not yet support adding a ramdisk / initrd. +"""

+import argparse +import collections +import os +import subprocess +import sys +import tempfile +import time

+import libfdt

+# Tool extension and the name of the command-line tools +CompTool = collections.namedtuple('CompTool', 'ext,tools')

+COMP_TOOLS = {

• 'bzip2': CompTool('.bz2', 'bzip2'),
• 'gzip': CompTool('.gz', 'pigz,gzip'),
• 'lz4': CompTool('.lz4', 'lz4'),
• 'lzma': CompTool('.lzma', 'lzma'),
• 'lzo': CompTool('.lzo', 'lzop'),
• 'zstd': CompTool('.zstd', 'zstd'),

+}

+def parse_args():

• """Parse the program ArgumentParser
• Returns:

•    Namespace object containing the arguments
  

• """
• epilog = 'Build a FIT from a directory tree containing .dtb files'
• parser = argparse.ArgumentParser(epilog=epilog)
• parser.add_argument('-A', '--arch', type=str, required=True,

•      help='Specifies the architecture')
  

• parser.add_argument('-c', '--compress', type=str, default='none',

•      help='Specifies the compression')
  

• parser.add_argument('-E', '--external', action='store_true',

•      help='Convert the FIT to use external data')
  

• parser.add_argument('-n', '--name', type=str, required=True,

•      help='Specifies the name')
  

• parser.add_argument('-O', '--os', type=str, required=True,

•      help='Specifies the operating system')
  

• parser.add_argument('-f', '--fit', type=str, required=True,

•      help='Specifies the output file (.fit)')
  

• parser.add_argument('-k', '--kernel', type=str, required=True,

•      help='Specifies the (uncompressed) kernel input file (.itk)')
  

• parser.add_argument('srcdir', type=str, nargs='*',

•      help='Specifies the directory tree that contains .dtb files')
  

• return parser.parse_args()

+def setup_fit(fsw, name):

• """Make a start on writing the FIT
• Outputs the root properties and the 'images' node
• Args:

•    fsw (libfdt.FdtSw): Object to use for writing
  

•    name (str): Name of kernel image
  

• """
• fsw.INC_SIZE = 65536
• fsw.finish_reservemap()
• fsw.begin_node('')
• fsw.property_string('description', f'{name} with devicetree set')
• fsw.property_u32('#address-cells', 1)
• fsw.property_u32('timestamp', int(time.time()))
• fsw.begin_node('images')

+def write_kernel(fsw, data, args):

• """Write out the kernel image
• Writes a kernel node along with the required properties
• Args:

•    fsw (libfdt.FdtSw): Object to use for writing
  

•    data (bytes): Data to write (possibly compressed)
  

•    args (Namespace): Contains necessary strings:
  

•        arch: FIT architecture, e.g. 'arm64'
  

•        fit_os: Operating Systems, e.g. 'linux'
  

•        name: Name of OS, e.g. 'Linux-6.6.0-rc7'
  

•        compress: Compression algorithm to use, e.g. 'gzip'
  

• """
• with fsw.add_node('kernel'):

•    fsw.property_string('description', args.name)
  

•    fsw.property_string('type', 'kernel_noload')
  

•    fsw.property_string('arch', args.arch)
  

•    fsw.property_string('os', args.os)
  

•    fsw.property_string('compression', args.compress)
  

•    fsw.property('data', data)
  

•    fsw.property_u32('load', 0)
  

•    fsw.property_u32('entry', 0)
  

+def finish_fit(fsw, entries):

• """Finish the FIT ready for use
• Writes the /configurations node and subnodes
• Args:

•    fsw (libfdt.FdtSw): Object to use for writing
  

•    entries (list of tuple): List of configurations:
  

•        str: Description of model
  

•        str: Compatible stringlist
  

• """
• fsw.end_node()
• seq = 0
• with fsw.add_node('configurations'):

•    for model, compat in entries:
  

•        seq += 1
  

•        with fsw.add_node(f'conf-{seq}'):
  

•            fsw.property('compatible', bytes(compat))
  

•            fsw.property_string('description', model)
  

•            fsw.property_string('fdt', f'fdt-{seq}')
  

•            fsw.property_string('kernel', 'kernel')
  

• fsw.end_node()

+def compress_data(inf, compress):

• """Compress data using a selected algorithm
• Args:

•    inf (IOBase): Filename containing the data to compress
  

•    compress (str): Compression algorithm, e.g. 'gzip'
  

• Return:

•    bytes: Compressed data
  

• """
• if compress == 'none':

•    return inf.read()
  

• comp = COMP_TOOLS.get(compress)
• if not comp:

•    raise ValueError(f"Unknown compression algorithm '{compress}'")
  

• with tempfile.NamedTemporaryFile() as comp_fname:

•    with open(comp_fname.name, 'wb') as outf:
  

•        done = False
  

•        for tool in comp.tools.split(','):
  

•            try:
  

•                subprocess.call([tool, '-c'], stdin=inf, stdout=outf)
  

•                done = True
  

•                break
  

•            except FileNotFoundError:
  

•                pass
  

•        if not done:
  

•            raise ValueError(f'Missing tool(s): {comp.tools}\n')
  

•        with open(comp_fname.name, 'rb') as compf:
  

•            comp_data = compf.read()
  

• return comp_data

+def output_dtb(fsw, seq, fname, arch, compress):

• """Write out a single devicetree to the FIT
• Args:

•    fsw (libfdt.FdtSw): Object to use for writing
  

•    seq (int): Sequence number (1 for first)
  

•    fmame (str): Filename containing the DTB
  

•    arch: FIT architecture, e.g. 'arm64'
  

•    compress (str): Compressed algorithm, e.g. 'gzip'
  

• Returns:

•    tuple:
  

•        str: Model name
  

•        bytes: Compatible stringlist
  

• """
• with fsw.add_node(f'fdt-{seq}'):

•    # Get the compatible / model information
  

•    with open(fname, 'rb') as inf:
  

•        data = inf.read()
  

•    fdt = libfdt.FdtRo(data)
  

•    model = fdt.getprop(0, 'model').as_str()
  

•    compat = fdt.getprop(0, 'compatible')
  

•    fsw.property_string('description', model)
  

•    fsw.property_string('type', 'flat_dt')
  

•    fsw.property_string('arch', arch)
  

•    fsw.property_string('compression', compress)
  

•    fsw.property('compatible', bytes(compat))
  

•    with open(fname, 'rb') as inf:
  

•        compressed = compress_data(inf, compress)
  

•    fsw.property('data', compressed)
  

• return model, compat

+def build_fit(args):

• """Build the FIT from the provided files and arguments
• Args:

•    args (Namespace): Program arguments
  

• Returns:

•    tuple:
  

•        bytes: FIT data
  

•        int: Number of configurations generated
  

•        size: Total uncompressed size of data
  

• """
• fsw = libfdt.FdtSw()
• setup_fit(fsw, args.name)
• seq = 0
• size = 0
• entries = []
• # Handle the kernel
• with open(args.kernel, 'rb') as inf:

•    comp_data = compress_data(inf, args.compress)
  

• size += os.path.getsize(args.kernel)
• write_kernel(fsw, comp_data, args)
• for path in args.srcdir:

•    # Handle devicetree files
  

•    if os.path.isdir(path):
  

•        for dirpath, _, fnames in os.walk(path):
  

•            for fname in fnames:
  

•                if os.path.splitext(fname)[1] != '.dtb':
  

•                    continue
  

•                pathname = os.path.join(dirpath, fname)
  

•                seq += 1
  

•                size += os.path.getsize(pathname)
  

•                model, compat = output_dtb(fsw, seq, pathname,
  

•                                           args.arch, args.compress)
  

•                entries.append([model, compat])
  

• finish_fit(fsw, entries)
• # Include the kernel itself in the returned file count
• return fsw.as_fdt().as_bytearray(), seq + 1, size

+def run_make_fit():

• """Run the tool's main logic"""
• args = parse_args()
• out_data, count, size = build_fit(args)
• with open(args.fit, 'wb') as outf:

•    outf.write(out_data)
  

• ext_fit_size = None
• if args.external:

•    mkimage = os.environ.get('MKIMAGE', 'mkimage')
  

Do we need to add a 'mkimage' line in Documentation/process/changes.rst?

Kind regards, Nicolas

•    subprocess.check_call([mkimage, '-E', '-F', args.fit],
  

•                          stdout=subprocess.DEVNULL)
  

•    with open(args.fit, 'rb') as inf:
  

•        data = inf.read()
  

•    ext_fit = libfdt.FdtRo(data)
  

•    ext_fit_size = ext_fit.totalsize()
  

• comp_size = len(out_data)
• print(f'FIT size {comp_size:#x}/{comp_size / 1024 / 1024:.1f} MB', end='')
• if ext_fit_size:

•    print(f', header {ext_fit_size:#x}/{ext_fit_size / 1024:.1f} KB', end='')
  

• print(f', {count} files, uncompressed {size / 1024 / 1024:.1f} MB')

+if __name__ == "__main__":

• sys.exit(run_make_fit())

-- 2.43.0.rc2.451.g8631bc7472-goog

On Thu, Nov 30, 2023 at 2:22 AM Simon Glass sjg@chromium.org wrote:

Add a script which produces a Flat Image Tree (FIT), a single file containing the built kernel and associated devicetree files. Compression defaults to gzip which gives a good balance of size and performance.

The files compress from about 86MB to 24MB using this approach.

The FIT can be used by bootloaders which support it, such as U-Boot and Linuxboot. It permits automatic selection of the correct devicetree, matching the compatible string of the running board with the closest compatible string in the FIT. There is no need for filenames or other workarounds.

Add a 'make image.fit' build target for arm64, as well.

The FIT can be examined using 'dumpimage -l'.

This features requires pylibfdt (use 'pip install libfdt'). It also requires compression utilities for the algorithm being used. Supported compression options are the same as the Image.xxx files. For now there is no way to change the compression other than by editing the rule for $(obj)/image.fit

While FIT supports a ramdisk / initrd, no attempt is made to support this here, since it must be built separately from the Linux build.

Signed-off-by: Simon Glass sjg@chromium.org

Changes in v7:

• Add Image as a dependency of image.fit
• Drop kbuild tag
• Add dependency on dtbs
• Drop unnecessary path separator for dtbs
• Rebase to -next

Changes in v5:

• Drop patch previously applied
• Correct compression rule which was broken in v4

Changes in v4:

• Use single quotes for UIMAGE_NAME

Changes in v3:

• Drop temporary file image.itk
• Drop patch 'Use double quotes for image name'
• Drop double quotes in use of UIMAGE_NAME
• Drop unnecessary CONFIG_EFI_ZBOOT condition for help
• Avoid hard-coding "arm64" for the DT architecture

Changes in v2:

• Drop patch previously applied
• Add .gitignore file
• Move fit rule to Makefile.lib using an intermediate file
• Drop dependency on CONFIG_EFI_ZBOOT
• Pick up .dtb files separately from the kernel
• Correct pylint too-many-args warning for write_kernel()
• Include the kernel image in the file count
• Add a pointer to the FIT spec and mention of its wide industry usage
• Mention the kernel version in the FIT description

MAINTAINERS | 7 + arch/arm64/Makefile | 9 +- arch/arm64/boot/.gitignore | 1 + arch/arm64/boot/Makefile | 6 +- scripts/Makefile.lib | 13 ++ scripts/make_fit.py | 289 +++++++++++++++++++++++++++++++++++++ 6 files changed, 322 insertions(+), 3 deletions(-) create mode 100755 scripts/make_fit.py

diff --git a/MAINTAINERS b/MAINTAINERS index 14587be87a33..d609f0e8deb3 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -1585,6 +1585,13 @@ F: Documentation/process/maintainer-soc*.rst F: arch/arm/boot/dts/Makefile F: arch/arm64/boot/dts/Makefile

+ARM64 FIT SUPPORT +M: Simon Glass sjg@chromium.org +L: linux-arm-kernel@lists.infradead.org (moderated for non-subscribers) +S: Maintained +F: arch/arm64/boot/Makefile +F: scripts/make_fit.py

ARM ARCHITECTED TIMER DRIVER M: Mark Rutland mark.rutland@arm.com M: Marc Zyngier maz@kernel.org diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile index 1bd4fae6e806..18e092de7cdb 100644 --- a/arch/arm64/Makefile +++ b/arch/arm64/Makefile @@ -36,6 +36,8 @@ ifeq ($(CONFIG_BROKEN_GAS_INST),y) $(warning Detected assembler with broken .inst; disassembly will be unreliable) endif

+KBUILD_DTBS := dtbs

Please remove this, and hard-code

image.fit: dtbs

$(obj)/Image: vmlinux FORCE $(call if_changed,objcopy) @@ -39,6 +40,9 @@ $(obj)/Image.lzo: $(obj)/Image FORCE $(obj)/Image.zst: $(obj)/Image FORCE $(call if_changed,zstd)

+$(obj)/image.fit: $(obj)/Image FORCE

•   $(call cmd,fit,gzip)
  

The gzip parameter is not used. Please do

$(call cmd,fit)

In the python script, functions are separated with two blank lines, but there is only one blank line between parse_args() and setup_fit().

I do not mind either way because it does not contain any class, but please keep consistency.

-- Best Regards Masahiro Yamada