nixpkgs/boot/boot-stage-1-init.sh

#! @staticShell@

fail() {
    # If starting stage 2 failed, start an interactive shell.
    echo "Stage 2 failed, starting emergency shell..."
    exec @staticShell@
}


# Print a greeting.
echo
echo "<<< NixOS Stage 1 >>>"
echo


# Set the PATH.
export PATH=/empty
for i in @path@; do
    PATH=$PATH:$i/bin
    if test -e $i/sbin; then
        PATH=$PATH:$i/sbin
    fi
done


# Mount special file systems.
mkdir -p /etc # to shut up mount
touch /etc/fstab # idem
mkdir -p /proc
mount -t proc none /proc
mkdir -p /sys
mount -t sysfs none /sys


# Process the kernel command line.
stage2Init=@stage2Init@
for o in $(cat /proc/cmdline); do
    case $o in
        init=*)
            set -- $(IFS==; echo $o)
            stage2Init=$2
            ;;
        debugtrace)
            # Show each command.
            set -x
            ;;
        debug1)
            fail
            ;;
    esac
done


# Create device nodes in /dev.
source @makeDevices@


# Load some kernel modules.
export MODULE_DIR=@modulesDir@/lib/modules/
for i in @modules@; do
    modprobe $i
done


# Try to find and mount the root device.
mkdir /mnt
mkdir /mnt/root

echo "mounting the root device..."

if test -n "@autoDetectRootDevice@"; then

    # Look for the root device by label.
    echo "probing for the NixOS installation CD..."

    for i in /sys/devices/*/*/media; do
        if test "$(cat $i)" = "cdrom"; then

            # Hopefully `drivename' matches the device created in /dev.
            devName=/dev/$(cat $(dirname $i)/drivename)

            echo "  in $devName..."

            if mount -n -o ro -t iso9660 $devName /mnt/root; then
                if test -e "/mnt/root/@rootLabel@"; then
                    found=1
                    break
                fi
                umount /mnt/root
            fi
        
        fi
    done

    if test -z "$found"; then
        echo "CD not found!"
        fail
    fi

else

    # Hard-coded root device.
    rootDevice="@rootDevice@"

    # Check the root device.
    fsck -C -a "$rootDevice"
    fsckResult=$?

    if test $(($fsckResult | 2)) = $fsckResult; then
        echo "fsck finished, rebooting..."
        sleep 3
        # reboot -f -d !!! don't have reboot yet
        fail
    fi

    if test $(($fsckResult | 4)) = $fsckResult; then
        echo "$rootDevice has unrepaired errors, please fix them manually."
        fail
    fi

    if test $fsckResult -ge 8; then
        echo "fsck on $rootDevice failed."
        fail
    fi

    # Mount read-writable.
    mount -n -o rw "$rootDevice" /mnt/root || fail

fi


# Start stage 2.
# !!! Note: we can't use pivot_root here (the kernel gods have
# decreed), but we could use run-init from klibc, which deletes all
# files in the initramfs, remounts the target root on /, and chroots.
cd /mnt/root
mount --move . /
umount /proc # cleanup
umount /sys

echo "INIT = $stage2Init"

if test -z "$stage2Init"; then fail; fi

exec chroot . $stage2Init

fail