PSXHAX

#!/boot/bzImage

# Linux kernel initialization code, translated to bash
# (Minus floppy disk handling, because seriously, it's 2017.)
# Not 100% accurate, but gives you a good idea of how kernel init works
# GPLv2, Copyright 2017 Hector Martin <[email protected]>
# Based on Linux 4.10-rc2.

# Note: pretend chroot is a builtin and affects the current process
# Note: kernel actually uses major/minor device numbers instead of device name
#       strings in a few places, but I simplified it by using strings
#       everywhere even though that is not completely accurate.

panic() {
    echo "$*"
    while true; do
        sleep 1
    done
}

do_mount_root() {
    mount -t $2 "$1" /root $rootflags || return $?
    cd /root
    echo "VFS: Mounted root ($2 filesystem) on device $major:$minor"
}

mount_block_root() {
    if [ -z $rootfstype ]; then
        rootfstype=$built_in_filesystem_types
    fi
    for fs in ${rootfstype//,/ }; do
        do_mount_root $1 $fs
        ret=$?
        case $ret in
            13|22) # EACCES or EINVAL
                ;;
            *)
                echo "VFS: Cannot open root device \"$root_device_name\" or $1: error $ret"
                echo "Please append a correct \"root=\" boot option; here are the available partitions:"
                printk_all_partitions
                panic "VFS: Unable to mount root fs on $1"
        esac
    done
    echo "List of all partitions:"
    printk_all_partitions
    echo "No filesystem could mount root, tried...