Build Debian kernel manually from source
Posted by Anonymous on Mon 4th Apr 2022 09:15
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modification of post by Anonymous (view diff)

#!/usr/bin/ksh93

#
# Build Debian RT kernel from source,
# and retain the kernel build including source and *.o
# files so we can build custom kernel modules from
# that
#

compound bconfig=(
        # config
        typeset kernel_maj_min='5.10'
        # 32bit == 'config.i386_rt_686-pae', 64bit == 'config.amd64_rt_amd64'
        typeset kernel_config_name='config.amd64_rt_amd64'
        typeset igb_avb_src_gitbundle='/home/rmainz/work/dev_current/dev026/elbe/igb_avb/rovema_igb_avb_git20220302_001.bundle'
        typeset simatic_src_gitbundle='/home/rmainz/work/dev_current/dev026/elbe/simatickernelmodules/rovema_simatickernelmodules_git20220304_001.bundle'

        # calculated values
        typeset kernel_build_path
)

function build_debian_kernel_from_src
{
        set -o xtrace
        set -o errexit
        set -o nounset

        integer res
        integer num_cpus=$(getconf '_NPROCESSORS_CONF')

        tar xf "/usr/src/linux-source-${bconfig.kernel_maj_min}.tar.xz"

        cd "linux-source-${bconfig.kernel_maj_min}"

        unxz <"/usr/src/linux-patch-${bconfig.kernel_maj_min}-rt.patch.xz" | patch -p1

        cp "/usr/src/linux-config-${bconfig.kernel_maj_min}/${bconfig.kernel_config_name}.xz" .
        unxz "${bconfig.kernel_config_name}.xz"

        # copy config and make kernel build accept it without
        # jumping to the $ make menu # menu
        cp "${bconfig.kernel_config_name}" '.config'
        make oldconfig <'/dev/null'

        # show any modifications $ make oldconfig # did to the kernel config
        print '--------------------------------------'
        diff -u "${bconfig.kernel_config_name}" '.config' || true
        print '--------------------------------------'

        make clean
        time nice -n 19 make -j$((num_cpus*4)) deb-pkg 2>&1 | tee -a buildlog.log
        (( res=$? ))

        printf '#### Kernel build finished, return code = %d\n' res

        if (( res == 0 )) ; then
                # remember the path to the kernel build, but only if we were successful
                bconfig.kernel_build_path="$PWD/"
        fi

        return $res
}

function build_simatic_kernel_modules
{
        set -o xtrace
        set -o errexit
        set -o nounset

        # dummy for now
        #simatic-ipc-modules-lsp-v1.2.0RC1$ make -C /home/rmainz/work/kernel_test001/linux-5.10.52/ M=$PWD

        rm -Rf simatic_build
        mkdir simatic_build
        cd simatic_build

        cp "${bconfig.simatic_src_gitbundle}" .
        git clone rovema_simatickernelmodules_git20220304_001.bundle

        cd rovema_simatickernelmodules_git20220304_001/simatic-ipc-modules-lsp-v1.2.0RC1/
        make -C "${bconfig.kernel_build_path}" KSRC="${bconfig.kernel_build_path}" M=$PWD

        #
        # ToDo: Install in root/ dir, and turn that filesystem hieracy into a
        # Debian package
        # see https://unix.stackexchange.com/questions/30303/how-to-create-a-deb-file-manually
        #

        return 1
}


function build_igb_avb_kernel_module
{
        set -o xtrace
        set -o errexit
        set -o nounset

        rm -Rf igb_avb_build
        mkdir igb_avb_build
        cd igb_avb_build

        cp "${bconfig.igb_avb_src_gitbundle}" .
        git clone rovema_igb_avb_git20220302_001.bundle

        cd rovema_igb_avb_git20220302_001/kmod

        make -C "${bconfig.kernel_build_path}" KSRC="${bconfig.kernel_build_path}" M=$PWD clean
        make -C ${bconfig.kernel_build_path} KSRC="${bconfig.kernel_build_path}" M=$PWD


        cd ../lib
        make

        #
        # ToDo: Install in root/ dir, and turn that filesystem hieracy into a
        # Debian package
        #

        # dummy for now
        # see https://unix.stackexchange.com/questions/30303/how-to-create-a-deb-file-manually

        return 1
}

function main
{
        set -o xtrace
        set -o errexit
        set -o nounset

        typeset bbd="$PWD" # base build directory

        if (( 1 )) ; then
                cd $bbd && build_debian_kernel_from_src
        else
                bconfig.kernel_build_path="$PWD/linux-source-${bconfig.kernel_maj_min}/"
        fi
        cd $bbd ; build_simatic_kernel_modules || true
        cd $bbd ; build_igb_avb_kernel_module
}

#
# main
#
builtin getconf

main "$@"

# EOF.