# git rev-parse -q --verify 580856e843f091a91f133b311d3e19e3d4374a21^{commit}
580856e843f091a91f133b311d3e19e3d4374a21
already have revision, skipping fetch
# git checkout -q -f -B kisskb 580856e843f091a91f133b311d3e19e3d4374a21
# git clean -qxdf
# < git log -1
# commit 580856e843f091a91f133b311d3e19e3d4374a21
# Author: Parth Pancholi <parth.pancholi@toradex.com>
# Date:   Thu Nov 14 15:56:44 2024 +0100
# 
#     kbuild: switch from lz4c to lz4 for compression
#     
#     Replace lz4c with lz4 for kernel image compression.
#     Although lz4 and lz4c are functionally similar, lz4c has been deprecated
#     upstream since 2018. Since as early as Ubuntu 16.04 and Fedora 25, lz4
#     and lz4c have been packaged together, making it safe to update the
#     requirement from lz4c to lz4.
#     
#     Consequently, some distributions and build systems, such as OpenEmbedded,
#     have fully transitioned to using lz4. OpenEmbedded core adopted this
#     change in commit fe167e082cbd ("bitbake.conf: require lz4 instead of
#     lz4c"), causing compatibility issues when building the mainline kernel
#     in the latest OpenEmbedded environment, as seen in the errors below.
#     
#     This change also updates the LZ4 compression commands to make it backward
#     compatible by replacing stdin and stdout with the '-' option, due to some
#     unclear reason, the stdout keyword does not work for lz4 and '-' works for
#     both. In addition, this modifies the legacy '-c1' with '-9' which is also
#     compatible with both. This fixes the mainline kernel build failures with
#     the latest master OpenEmbedded builds associated with the mentioned
#     compatibility issues.
#     
#     LZ4     arch/arm/boot/compressed/piggy_data
#     /bin/sh: 1: lz4c: not found
#     ...
#     ...
#     ERROR: oe_runmake failed
#     
#     Link: https://github.com/lz4/lz4/pull/553
#     Suggested-by: Francesco Dolcini <francesco.dolcini@toradex.com>
#     Signed-off-by: Parth Pancholi <parth.pancholi@toradex.com>
#     Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
# < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version
# < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-ld --version
# < git log --format=%s --max-count=1 580856e843f091a91f133b311d3e19e3d4374a21
# make -s -j 32 ARCH=powerpc O=/kisskb/build/kbuild_pmac32_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  pmac32_defconfig
# < make -s -j 32 ARCH=powerpc O=/kisskb/build/kbuild_pmac32_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  help
# make -s -j 32 ARCH=powerpc O=/kisskb/build/kbuild_pmac32_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  olddefconfig
# make -s -j 32 ARCH=powerpc O=/kisskb/build/kbuild_pmac32_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  
Completed OK
# rm -rf /kisskb/build/kbuild_pmac32_defconfig_powerpc-gcc5
# Build took: 0:01:22.596363