#!/bin/bash

# Author: prog32bit
# Description: autocompile & install kernel

function download-and-extract {
        rm -rf temporary > /dev/null
        mkdir temporary
        cd temporary
        wget -q --show-progress https://cdn.kernel.org/pub/linux/kernel/v4.x/linux-4.10.6.tar.xz https://cdn.kernel.org/pub/linux/kernel/v4.x/linux-4.10.6.tar.sign
        unxz linux-4.10.6.tar.xz
        gpg --keyserver hkp://keys.gnupg.net --recv-keys 38DBBDC86092693E
        if gpg --verify linux-4.10.6.tar.sign
        then
                cd ..
                tar -xf temporary/linux-4.10.6.tar
                rm -rf temporary
        else
                cd ..
                download-and-extract
        fi
}

function build {
        zcat /proc/config.gz > .config
        yes "" | make oldconfig
        make -j4
        make -j4 modules
}

function kernel-install {
        # follow commands run as root
        make install
        make modules_install
        # in this folder places all variants to '-k': /usr/lib/modules
        mkinitcpio -k 4.10.6-MANJARO -g /boot/initramfs-4.10.6-x86_64.img
        mv /boot/vmlinuz /boot/vmlinuz-4.10.6-x86_64
        grub-mkconfig -o /boot/grub/grub.cfg
}
export -f kernel-install

function main {
        download-and-extract
        cd linux-4.10.6
        build
        su -c 'kernel-install'
}

main