Hi Masahiro, Tom,
On Tue, 9 Jan 2024 at 07:33, Tom Rini trini@konsulko.com wrote:
On Tue, Jan 09, 2024 at 11:01:42PM +0900, Masahiro Yamada wrote:
Hi Simon,
On Wed, Jan 3, 2024 at 8:47 AM Simon Glass sjg@chromium.org wrote:
Hi Masahiro,
On Wed, Dec 13, 2023 at 5:14 AM Will Deacon will@kernel.org wrote:
On Fri, Dec 01, 2023 at 08:54:42PM -0700, 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.
Add a 'make image.fit' build target for arm64, as well. Use FIT_COMPRESSION to select a different algorithm.
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 $(obj)/image.fit
While FIT supports a ramdisk / initrd, no attempt is made to support this here, since it must be built separately from the Linux build.
Signed-off-by: Simon Glass sjg@chromium.org
Changes in v9:
- Move the compression control into Makefile.lib
Changes in v8:
- Drop compatible string in FDT node
- Correct sorting of MAINTAINERS to before ARM64 PORT
- Turn compress part of the make_fit.py comment in to a sentence
- Add two blank lines before parse_args() and setup_fit()
- Use 'image.fit: dtbs' instead of BUILD_DTBS var
- Use '$(<D)/dts' instead of '$(dir $<)dts'
- Add 'mkimage' details Documentation/process/changes.rst
- Allow changing the compression used
- Tweak cover letter since there is only one clean-up patch
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
Documentation/process/changes.rst | 9 + MAINTAINERS | 7 + arch/arm64/Makefile | 7 +- arch/arm64/boot/.gitignore | 1 + arch/arm64/boot/Makefile | 6 +- scripts/Makefile.lib | 16 ++ scripts/make_fit.py | 291 ++++++++++++++++++++++++++++++ 7 files changed, 334 insertions(+), 3 deletions(-) create mode 100755 scripts/make_fit.py
I'll need Masahiro's Ack on the scripts/ changes before I can take this one.
Any thoughts on this request, please?
Regards, Simon
As I mentioned before, I am concerned with having the same "compatible" entries, with different contents, as you use the "compatible" string as an ID to selecting the target config node, right?
$ fdtdump arch/arm64/boot/image.fit
... conf-10 { compatible = "tq,am642-tqma6442l-mbax4xxl","tq,am642-tqma6442l", "ti,am642"; description = "TQ-Systems TQMa64xxL SoM on MBax4xxL carrier board"; fdt = "fdt-10"; kernel = "kernel"; };
... conf-25 { compatible = "tq,am642-tqma6442l-mbax4xxl","tq,am642-tqma6442l", "ti,am642"; description = "TQ-Systems TQMa64xxL SoM on MBax4xxL carrier board"; fdt = "fdt-25"; kernel = "kernel"; };
I had asked Rob a while ago about if having the same compatible for two functionally different machines is a feature, or a bug, and I don't think either of us fully agreed either way. I'd be leaning towards saying the above example is a bug in the dts files, it's just not been a bug people have worried about before due to (sadly) how little the top-level compatible has been used.
Yes I believe this is a bug in the files.
What should the script do in this case? Print a warning, perhaps?
Regards, Simon