On Thu, Nov 30, 2023 at 5:26 PM Nicolas Schier nicolas@fjasle.eu wrote:
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?
I recommend not touching MIPS at this moment because this tool simply picks up *.dtb files that exist under arch/*/boot/dts/, some of which may be stale files.
Think of this scenario:
[1] Enable CONFIG_ARCH_FOO and build
foo.dtb
will be created.
[2] Next, disable CONFIG_ARCH_FOO and enable CONFIG_ARCH_BAR, and build.
bar.dtb
will be created.
This script will pick up both foo.dtb and bar.dtb although foo.dtb is a left-over from the previous build.
Without cleaning, stale *.dtb will accumulate and unwanted files will be included in image.fit.
Currently, MIPS hard-codes its files. It always works in a deterministic way.
I do not request Simon to implement everything perfectly because I know that would require much more effort.
We could do something like modules.order to list out the dtb files from the current build, but I am not asking for it in this patchset.
But, you are right. This tool is not arm64-specific at all (and that is the reason why I think the MAINTAINERS entry is a little odd) Perhaps it can be applicable to MIPS after everything works correctly.
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?
This should not exist in the first place.
image.fit: dtbs
is better.
-- Best Regards Masahiro Yamada