[PATCH] arm64: Allow packing uncompressed images into distro packages

[Bjorn Andersson]

On Fri, Aug 23, 2024 at 11:58:54AM +0100, Will Deacon wrote:
> On Mon, Aug 19, 2024 at 08:11:58PM -0700, Bjorn Andersson wrote:
> > From: Bjorn Andersson <quic_bjorande at quicinc.com>
> > 
> > The distro packages (deb-pkg, pacman-pkg, rpm-pkg) are generated using
> > the compressed kernel image, which means that the kernel once installed
> > can not be booted with systemd-boot.
> > 
> > This differs from the packages generated by the distros themselves,
> > which uses the uncompressed image.
> > 
> > Expand the newly introduced CONFIG_COMPRESSED_INSTALL option to allow
> > selection of which version of the kernel image should be packaged into
> > the distro packages.
> > 
> > Signed-off-by: Bjorn Andersson <quic_bjorande at quicinc.com>
> > ---
> >  arch/arm64/Makefile | 15 ++++++---------
> >  1 file changed, 6 insertions(+), 9 deletions(-)
> > 
> > diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
> > index f6bc3da1ef11..7bb9a0a5500a 100644
> > --- a/arch/arm64/Makefile
> > +++ b/arch/arm64/Makefile
> > @@ -166,9 +166,13 @@ BOOT_TARGETS	:= Image vmlinuz.efi image.fit
> >  PHONY += $(BOOT_TARGETS)
> >  
> >  ifeq ($(CONFIG_EFI_ZBOOT),)
> > -KBUILD_IMAGE	:= $(boot)/Image.gz
> > +  ifeq ($(CONFIG_COMPRESSED_INSTALL),y)
> > +    KBUILD_IMAGE := $(boot)/Image.gz
> > +  else
> > +    KBUILD_IMAGE := $(boot)/Image
> > +  endif
> >  else
> > -KBUILD_IMAGE	:= $(boot)/vmlinuz.efi
> > +  KBUILD_IMAGE := $(boot)/vmlinuz.efi
> >  endif
> >  
> >  all:	$(notdir $(KBUILD_IMAGE))
> > @@ -182,13 +186,6 @@ $(BOOT_TARGETS): vmlinux
> >  Image.%: Image
> >  	$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
> >  
> > -ifeq ($(CONFIG_COMPRESSED_INSTALL),y)
> > - DEFAULT_KBUILD_IMAGE = $(KBUILD_IMAGE)
> > -else
> > - DEFAULT_KBUILD_IMAGE = $(boot)/Image
> > -endif
> > -
> > -install: KBUILD_IMAGE := $(DEFAULT_KBUILD_IMAGE)
> 
> Hmm, doesn't this mean that we always install vmlinuz.efi if
> CONFIG_EFI_ZBOOT=y?
> 

Hmm, you're right, I failed to parse that part.

That said, prior to Linus' change we'd always install "Image" and I read
his commit message to allow installing "Image.gz".

But the change also made it possible to install "vmlinuz.efi", by
setting both options to =y. Was this intentional?

Can you confirm that this is what we want:

ZBOOT | COMPRESS | BUILD_IMAGE | install
------+----------+-------------+--------
  N   |    N     | Image       | Image
  N   |    Y     | Image.gz    | Image.gz
  Y   |    N     | vmlinuz.efi | Image (?)
  Y   |    Y     | vmlinuz.efi | vmlinuz.efi (was Image in v6.10)

It seems reasonable to keep the two last entries in the "install" column
either "Image/Image.gz" or "vmlinuz.efi/vmlinuz.efi" (if it should be
possible to pass vmlinuz.efi to installkernel).

Regards,
Bjorn