Build kernel for raspberrypi and archive as tar for easy installation

rpi-buildskript.sh

#!/bin/bash
# inspired by the github-actions build-script https://github.com/raspberrypi/linux/blob/rpi-6.1.y/.github/workflows/kernel-build.yml

# on the pi, can be installed like so # SKIP_BACKUP=1 SKIP_DOWNLOAD=1 rpi-update http://192.168.178.32:8081/bcm2711_arm64_6.1.32-c2251ce04.tar.gz
set -x
name=bcm2711_arm64
arch=arm64
defconfig=bcm2711_defconfig
matrix_defconfig=$defconfig
kernel=kernel8
gh_wspace=/dev/shm/wspace

#rm -rf $gh_wspace
#mkdir -p $gh_wspace

export ARCH=$arch

        if [[ "$ARCH" == "arm64" ]]; then
          export CROSS_COMPILE=aarch64-linux-gnu-
          export DTS_SUBDIR=broadcom
          export IMAGE=Image.gz
        else
          export CROSS_COMPILE=arm-linux-gnueabihf-
          export DTS_SUBDIR=
          export IMAGE=zImage
        fi

        make O=$gh_wspace/build $matrix_defconfig
        scripts/config --file $gh_wspace/build/.config --set-val CONFIG_WERROR y
        scripts/config --file $gh_wspace/build/.config --set-val XFS_FS n
        scripts/config --file $gh_wspace/build/.config --set-val SOUND n
        scripts/config --file $gh_wspace/build/.config --set-val MEDIA_DIGITAL_TV_SUPPORT n
        scripts/config --file $gh_wspace/build/.config --set-val DVB_CORE n
        scripts/config --file $gh_wspace/build/.config --set-val NETWORK_FILESYSTEMS n
        scripts/config --file $gh_wspace/build/.config --set-val LOCALVERSION_AUTO y

        make O=$gh_wspace/build -j $(nproc) $IMAGE modules dtbs
        rm -rf $gh_wspace/install
        mkdir -p $gh_wspace/install/boot/overlays
        make O=$gh_wspace/build INSTALL_MOD_PATH=$gh_wspace/install modules_install
        cp $gh_wspace/build/arch/${ARCH}/boot/dts/${DTS_SUBDIR}/*.dtb $gh_wspace/install/boot/
        cp $gh_wspace/build/arch/${ARCH}/boot/dts/overlays/*.dtb* $gh_wspace/install/boot/overlays/
        cp $gh_wspace/arch/${ARCH}/boot/dts/overlays/README $gh_wspace/install/boot/overlays/
        cp $gh_wspace/build/arch/${ARCH}/boot/$IMAGE $gh_wspace/install/boot/$kernel.img
        buildver=$(find  $gh_wspace/install/lib/modules/  -maxdepth 1 -mindepth 1 -type d -exec basename {} \;)
        tar -czvf ${name}_$buildver.tar.gz -C $gh_wspace/install .