Re: [PATCH v6 3/5] linux-custom: Provide target and host specific kernel kbuild packages

[Jan Kiszka <jan.kiszka@siemens.com>]

On 14.02.24 11:10, Stefan Koch wrote:
> When using a cross build this patch does introduce
> target and host specific kernel kbuild packages that
> ship the "scripts" and "tools" binaries.
> 
> The "-kbuildtarget" and "-native" multiarch bitbake targets are useable to run
> additional target or host specific builds for kbuild scripts and tools.
> 
> Using the "-kbuildtarget" bitbake target enables the build of
> a target specific kbuild package at cross builds.
> So using "linux-kbuild" provides the package for the target platform.
> 
> Using the "-native" bitbake target enables the build of
> a host specific kbuild package at cross builds.
> When cross building using "linux-kbuild-native"
> provides the package for the host platform.
> 
> Only the "host" specific package is built automatically at cross builds.
> 
> This solves this from doc/custom_kernel.inc:
> - The kernel headers package has not supported both native
>   and cross compilation of kernel modules when itself was cross built
> - Future roadmap: Generate kernel headers package for both host
>   and target when using a cross build
> 
> Signed-off-by: Stefan Koch <stefan-koch@siemens.com>

This causes the kernel source packages being built twice, and the result 
is not even identical:

├── linux-starfive_6.6-visionfive2+r0.tar
│ ├── file list
│ │ @@ -28357,15 +28357,15 @@
│ │  -rw-r--r--   0        0        0     3843 2023-11-21 02:56:42.000000 linux-9fe004eaf1aa5b23bd5d03b4cfe9c3858bd884c4/crypto/xor.c
│ │  -rw-r--r--   0        0        0    12021 2023-11-21 02:56:42.000000 linux-9fe004eaf1aa5b23bd5d03b4cfe9c3858bd884c4/crypto/xts.c
│ │  -rw-r--r--   0        0        0     2445 2023-11-21 02:56:42.000000 linux-9fe004eaf1aa5b23bd5d03b4cfe9c3858bd884c4/crypto/xxhash_generic.c
│ │  -rw-r--r--   0        0        0     5090 2023-11-21 02:56:42.000000 linux-9fe004eaf1aa5b23bd5d03b4cfe9c3858bd884c4/crypto/zstd.c
│ │  drwxr-xr-x   0        0        0        0 2023-11-21 02:56:42.000000 linux-9fe004eaf1aa5b23bd5d03b4cfe9c3858bd884c4/debian/
│ │  -rw-r--r--   0        0        0      162 2023-11-21 02:56:42.000000 linux-9fe004eaf1aa5b23bd5d03b4cfe9c3858bd884c4/debian/changelog
│ │  -rw-r--r--   0        0        0        3 2023-11-21 02:56:42.000000 linux-9fe004eaf1aa5b23bd5d03b4cfe9c3858bd884c4/debian/compat
│ │ --rw-r--r--   0        0        0     2694 2023-11-21 02:56:42.000000 linux-9fe004eaf1aa5b23bd5d03b4cfe9c3858bd884c4/debian/control
│ │ +-rw-r--r--   0        0        0     2664 2023-11-21 02:56:42.000000 linux-9fe004eaf1aa5b23bd5d03b4cfe9c3858bd884c4/debian/control
│ │  drwxr-xr-x   0        0        0        0 2023-11-21 02:56:42.000000 linux-9fe004eaf1aa5b23bd5d03b4cfe9c3858bd884c4/debian/fragments/
│ │  -rw-r--r--   0        0        0      155 2023-11-21 02:56:42.000000 linux-9fe004eaf1aa5b23bd5d03b4cfe9c3858bd884c4/debian/fragments/starfive2_extra.cfg
│ │  drwxr-xr-x   0        0        0        0 2023-11-21 02:56:42.000000 linux-9fe004eaf1aa5b23bd5d03b4cfe9c3858bd884c4/debian/isar/
│ │  -rw-r--r--   0        0        0     1875 2023-11-21 02:56:42.000000 linux-9fe004eaf1aa5b23bd5d03b4cfe9c3858bd884c4/debian/isar/build
│ │  -rw-r--r--   0        0        0      355 2023-11-21 02:56:42.000000 linux-9fe004eaf1aa5b23bd5d03b4cfe9c3858bd884c4/debian/isar/clean
│ │  -rw-r--r--   0        0        0     1830 2023-11-21 02:56:42.000000 linux-9fe004eaf1aa5b23bd5d03b4cfe9c3858bd884c4/debian/isar/common
│ │  -rw-r--r--   0        0        0      587 2023-11-21 02:56:42.000000 linux-9fe004eaf1aa5b23bd5d03b4cfe9c3858bd884c4/debian/isar/configure
│ ├── linux-9fe004eaf1aa5b23bd5d03b4cfe9c3858bd884c4/debian/control
│ │ @@ -12,15 +12,15 @@
│ │  Description: starfive Linux kernel, version @KR@
│ │   This package contains the Linux kernel, modules and corresponding other
│ │   files, version: @KR@.
│ │  
│ │  Package: linux-headers-starfive
│ │  Build-Profiles: <kernel>
│ │  Architecture: any
│ │ -Depends: libc6,                                   libssl3,, linux-kbuild-starfive:amd64 | linux-kbuild-starfive, ${perl:Depends}, ${shlib:Depends}
│ │ +Depends: libc6,                                   libssl3,, linux-kbuild-starfive, ${perl:Depends}, ${shlib:Depends}
│ │  Description: starfive Linux kernel headers for @KR@
│ │   This package provides kernel header files for @KR@ on riscv64
│ │   .
│ │   This is useful for people who need to build external modules
│ │  
│ │  Package: linux-libc-dev
│ │  Build-Profiles: <!nolibcdev kernel>
│ ├── linux-9fe004eaf1aa5b23bd5d03b4cfe9c3858bd884c4/debian/linux-image-starfive.postinst
│ │ @@ -2,15 +2,15 @@
│ │  # based on https://salsa.debian.org/kernel-team/linux/blob/479cb120ecb2b3f2c4d929a7b57860248d6f79bd/debian/templates/image.postinst.in
│ │  # SPDX-License-Identifier: GPL-2.0-only
│ │  
│ │  # Tell initramfs builder whether it's wanted
│ │  export INITRD=Yes
│ │  
│ │  version=@KR@
│ │ -image_path=/boot/vmlinux-${version}
│ │ +image_path=/boot/vmlinuz-${version}
│ │  
│ │  if [ "$1" != configure ]; then
│ │      exit 0
│ │  fi
│ │  
│ │  depmod $version
│ ├── linux-9fe004eaf1aa5b23bd5d03b4cfe9c3858bd884c4/debian/linux-image-starfive.postrm
│ │ @@ -2,15 +2,15 @@
│ │  # based on https://salsa.debian.org/kernel-team/linux/blob/479cb120ecb2b3f2c4d929a7b57860248d6f79bd/debian/templates/image.postrm.in
│ │  # SPDX-License-Identifier: GPL-2.0-only
│ │  
│ │  # Tell initramfs builder whether it's wanted
│ │  export INITRD=Yes
│ │  
│ │  version=@KR@
│ │ -image_path=/boot/vmlinux-${version}
│ │ +image_path=/boot/vmlinuz-${version}
│ │  
│ │  rm -f /lib/modules/$version/.fresh-install
│ │  
│ │  if [ "$1" != upgrade ] && command -v linux-update-symlinks >/dev/null; then
│ │      linux-update-symlinks remove $version $image_path
│ │  fi
│ ├── linux-9fe004eaf1aa5b23bd5d03b4cfe9c3858bd884c4/debian/linux-image-starfive.preinst
│ │ @@ -2,15 +2,15 @@
│ │  # based on https://salsa.debian.org/kernel-team/linux/blob/479cb120ecb2b3f2c4d929a7b57860248d6f79bd/debian/templates/image.preinst.in
│ │  # SPDX-License-Identifier: GPL-2.0-only
│ │  
│ │  # Tell initramfs builder whether it's wanted
│ │  export INITRD=Yes
│ │  
│ │  version=@KR@
│ │ -image_path=/boot/vmlinux-${version}
│ │ +image_path=/boot/vmlinuz-${version}
│ │  
│ │  if [ "$1" = abort-upgrade ]; then
│ │      exit 0
│ │  fi
│ │  
│ │  if [ "$1" = install ]; then
│ │      # Create a flag file for postinst
│ ├── linux-9fe004eaf1aa5b23bd5d03b4cfe9c3858bd884c4/debian/linux-image-starfive.prerm
│ │ @@ -2,15 +2,15 @@
│ │  # based on https://salsa.debian.org/kernel-team/linux/blob/479cb120ecb2b3f2c4d929a7b57860248d6f79bd/debian/templates/image.prerm.in
│ │  # SPDX-License-Identifier: GPL-2.0-only
│ │  
│ │  # Tell initramfs builder whether it's wanted
│ │  export INITRD=Yes
│ │  
│ │  version=@KR@
│ │ -image_path=/boot/vmlinux-${version}
│ │ +image_path=/boot/vmlinuz-${version}
│ │  
│ │  if [ "$1" != remove ]; then
│ │      exit 0
│ │  fi
│ │  
│ │  linux-check-removal $version


Running the source build twice is not just a problem of the kernel 
recipe (the delta surely is and should be understood as well). But the 
kernel package is fairly large, so this at least wastes time. And if 
anyone would actually pull the sources from isar-apt during the build, 
we had an ugly race.

I have an (apparantely) working patch here that builds the sources only 
in the base package. Will share later.

Jan

-- 
Siemens AG, Technology
Linux Expert Center