Hi Masahiro,
On Fri, Oct 27, 2023 at 2:25 AM Masahiro Yamada masahiroy@kernel.org wrote:
On Thu, Oct 26, 2023 at 4:28 PM 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 85MB 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 $(obj)/image.fit
While FIT supports a ramdisk / initrd, no attempt is made to support this here, since it must be built separately from the Linux build.
Is this useful? For arm64, initrd is likely used.
It depends on your kernel configuration, though. I have found it convenient to enable the drivers necessary to boot.
FIT should be created in unbrellea projects such as OpenEmbedded, Buildroot, etc.
Sure, but that is a separate issue, isn't it? We already support various boot targets in arm64 but not one that includes the DTs, so far as I can see. The old arm 'uImage' target is pretty out-of-date now.
Signed-off-by: Simon Glass sjg@chromium.org
MAINTAINERS | 7 + arch/arm64/Makefile | 3 +- arch/arm64/boot/Makefile | 8 +- scripts/Makefile.lib | 16 ++- scripts/make_fit.py | 285 +++++++++++++++++++++++++++++++++++++++ 5 files changed, 315 insertions(+), 4 deletions(-) create mode 100755 scripts/make_fit.py
diff --git a/MAINTAINERS b/MAINTAINERS index 2d13bbd69adb..d6955ebc3c24 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -1575,6 +1575,13 @@ F: Documentation/process/maintainer-soc*.rst F: arch/arm/boot/dts/Makefile F: arch/arm64/boot/dts/Makefile
+ARM64 FIT SUPPORT +M: Simon Glass sjg@chromium.org +L: linux-arm-kernel@lists.infradead.org (moderated for non-subscribers) +S: Maintained +F: arch/arm64/boot/Makefile +F: scripts/make_fit.py
ARM ARCHITECTED TIMER DRIVER M: Mark Rutland mark.rutland@arm.com M: Marc Zyngier maz@kernel.org diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile index 7b77b63e978f..d8290dcab6b6 100644 --- a/arch/arm64/Makefile +++ b/arch/arm64/Makefile @@ -150,7 +150,7 @@ libs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a # Default target when executing plain make boot := arch/arm64/boot
-BOOT_TARGETS := Image.gz vmlinuz.efi +BOOT_TARGETS := Image.gz vmlinuz.efi image.fit
PHONY += $(BOOT_TARGETS)
@@ -215,6 +215,7 @@ virtconfig: define archhelp echo '* Image.gz - Compressed kernel image (arch/$(ARCH)/boot/Image.gz)' echo ' Image - Uncompressed kernel image (arch/$(ARCH)/boot/Image)' +$(if $(CONFIG_EFI_ZBOOT),,echo ' image.fit - Flat Image Tree (arch/$(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/Makefile b/arch/arm64/boot/Makefile index 1761f5972443..a6e5b20b22bd 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$(obj)/Image: vmlinux FORCE $(call if_changed,objcopy) @@ -39,6 +40,11 @@ $(obj)/Image.lzo: $(obj)/Image FORCE $(obj)/Image.zst: $(obj)/Image FORCE $(call if_changed,zstd)
+ifndef CONFIG_EFI_ZBOOT +$(obj)/image.fit: $(obj)/Image $(obj)/dts FORCE
This is wrong.
$(obj)/dts is a directory.
There is no point for comparing timestamps between $(obj)/image.fit and $(obj)/dts.
Updates of *.dtb do not result in the update of the $(obj)/dts timestamp.
if_changed never works correctly.
Yes I am aware that this doesn't actually deal with changes. I'll see if I can figure out another way.
$(call if_changed,fit,gzip)+endif
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 68d0134bdbf9..4e4364ad641a 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -487,14 +487,26 @@ UIMAGE_OPTS-y ?= UIMAGE_TYPE ?= kernel UIMAGE_LOADADDR ?= arch_must_set_this UIMAGE_ENTRYADDR ?= $(UIMAGE_LOADADDR) -UIMAGE_NAME ?= 'Linux-$(KERNELRELEASE)' +UIMAGE_NAME ?= "Linux-$(KERNELRELEASE)"
Unneeded noise change.
I'll move that to a separate patch. We don't want the single quotes in the name.
Regards, Simon