Hi Ahmad,
On Wed, 29 Nov 2023 at 11:35, Ahmad Fatoum a.fatoum@pengutronix.de wrote:
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?
The 'kernel_noload' type indicates that the load/exec address are ignored.
Please Cc me on subsequent revisions. I am interested in testing that this works for barebox too.
There has been some discussion about this recently in U-Boot too, along with a series [1] which you could try if you like.
The FIT spec[2] does not provide enough detail on exactly what kernel_noload means and we should improve this at some point.
Regards, Simon
[1] https://patchwork.ozlabs.org/project/uboot/list/?series=382849 [2] https://github.com/open-source-firmware/flat-image-tree
Thanks, Ahmad
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