pi-kernel

#!/usr/bin/env bash
#
# SPDX-License-Identifier: GPL-3.0-or-later
#
# Copyright (C) 2018 Nathan Chancellor
#
# Script to build and install a Raspberry Pi kernel image

source "$(cd "$(dirname "$(readlink -f "${BASH_SOURCE[0]}")")" || return; pwd)/common"
trap 'echo; die "Manually aborted!"' SIGINT SIGTERM

# Hide all non-error output unless verbosity is requsted
[[ ! "${*}" =~ "-v" ]] && exec > /dev/null

# Allow specification of 32-bit versus 64-bit
[[ "${*}" =~ "-32" ]] && ARCH=arm
[[ "${*}" =~ "-64" ]] && ARCH=arm64
[[ -z ${ARCH} ]] && ARCH=arm

# Kernel variable
KERNEL=kernel7

# Message file for Telegram messages
TG_MSG_FILE=$(mktemp)
trap 'rm -f "${TG_MSG_FILE}"' EXIT

# Check if we are compiling on the Raspberry Pi or not
[[ "$(whoami)" = "pi" ]] && PI=true

# Set toolchain to use
if [[ -n ${PI} ]]; then
    cd "${HOME}/Documents/Kernel" || die "Kernel source doesn't exist!"
else
    # SC2153: Possible misspelling: TC_FOLDER may not be assigned, but GCC_FOLDER is.
    # shellcheck disable=SC2153
    case "${*}" in
        *"-7"*) GCC_FOLDER=${TC_FOLDER}/btg-linaro-gcc-7.3.1-${ARCH} ;;
        *"-8"*) GCC_FOLDER=${TC_FOLDER}/btg-gcc-8.2.1-${ARCH} ;;
    esac
    [[ -z ${GCC_FOLDER} ]] && GCC_FOLDER=${TC_FOLDER}/btg-gcc-8.2.1-${ARCH}
    GCC=$(find "${GCC_FOLDER}/bin" \( -type f -o -type l \) -name '*-gcc' | head -n1)
    [[ -z ${GCC} ]] && die "GCC toolchain could not be found!"
    CC=${GCC%gcc}

    SOURCE_FOLDER=${HOME}/kernels/pi
    cd "${SOURCE_FOLDER}" || die "Kernel source doesn't exist!"
fi

# Make function for both host and cross compiling
function kmake() {
    if [[ -n ${PI} ]]; then
        make "${JOBS_FLAG}" O=out "${@}"
    else
        make "${JOBS_FLAG}" ARCH=${ARCH} CROSS_COMPILE="${CCACHE} ${CC}" O=out "${@}"
    fi
}

function build() {
    START="$(date +"%s")"

    {
        echo "\`\`\`"
        echo "Raspberry Pi kernel build starting..."
        echo
        echo "Version $(make kernelversion)"
        echo "\`\`\`"
    } > "${TG_MSG_FILE}"
    [[ -n ${PI} || "${*}" =~ "-t" ]] && notify "$(cat "${TG_MSG_FILE}")"

    rm -rf out

    if [[ ${ARCH} = "arm" ]]; then
        DEFCONFIG=bcm2709_defconfig
        IMAGE=zImage
    else
        DEFCONFIG=bcmrpi3_defconfig
        IMAGE=Image
    fi

    kmake "${DEFCONFIG}"

    if time kmake "${IMAGE}" modules dtbs; then
        RESULT_STRING="completed successfully"
    else
        RESULT_STRING="failed"
    fi

    {
        TIME_STRING="$(format_time "${START}" "$(date +"%s")")"
        echo "\`\`\`"
        echo "Raspberry Pi kernel build ${RESULT_STRING}!"
        echo
        echo "Duration: ${TIME_STRING,,}"
        echo "\`\`\`"
    } > "${TG_MSG_FILE}"
    [[ -n ${PI} || "${*}" =~ "-t" ]] && notify "$(cat "${TG_MSG_FILE}")"

    if [[ -z ${PI} ]]; then
        mkdir -p "${SOURCE_FOLDER}/out/pi_root"
        kmake INSTALL_MOD_PATH="${SOURCE_FOLDER}/out/pi_root" modules_install
    fi
}

function install() {
    if [[ -f out/arch/arm/boot/zImage ]]; then
        sudo make O=out modules_install
        sudo cp out/arch/arm/boot/dts/*.dtb /boot/
        sudo cp out/arch/arm/boot/dts/overlays/*.dtb* /boot/overlays/
        sudo cp arch/arm/boot/dts/overlays/README /boot/overlays/
        sudo cp out/arch/arm/boot/zImage /boot/$KERNEL.img
    fi
}

[[ "${*}" =~ "-b" ]] && build "${@}"
[[ "${*}" =~ "-i" && ${PI} ]] && install