[PATCH v9 0/2] arm64: Add a build target for Flat Image Tree

Simon Glass
2023-12-02T03:55:31Z

Flat Image Tree (FIT) is a widely used file format for packaging a
kernel and associated devicetree files[1]. It is not specific to any
one bootloader, as it is supported by U-Boot, coreboot, Linuxboot,
Tianocore and Barebox.

This series adds support for building a FIT as part of the kernel
build. This makes it easy to try out the kernel - just load the FIT
onto your tftp server and it will run automatically on any supported
arm64 board.

The script is written in Python, since it is easy to build a FIT using
the Python libfdt bindings. For now, no attempt is made to compress
files in parallel, so building the 900-odd files takes a while, about
6 seconds with my testing.

The series also includes a few minor clean-up patches.

[1] https://github.com/open-source-firmware/flat-image-tree

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:
- Drop the kbuild tag
- 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 v6:
- Drop the unwanted .gz suffix

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

Simon Glass (2):
arm64: Add BOOT_TARGETS variable
arm64: boot: Support Flat Image Tree

Documentation/process/changes.rst | 9 +
MAINTAINERS | 7 +
arch/arm64/Makefile | 11 +-
arch/arm64/boot/.gitignore | 1 +
arch/arm64/boot/Makefile | 6 +-
scripts/Makefile.lib | 16 ++
scripts/make_fit.py | 291 ++++++++++++++++++++++++++++++
7 files changed, 338 insertions(+), 3 deletions(-)
create mode 100755 scripts/make_fit.py

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2.43.0.rc2.451.g8631bc7472-goog