#!/bin/sh
set -eu

if [ $# -ne 2 ]
  then
    echo "Missing argument"
    echo "Usage: script.sh GRUB_HOME EFI_HOME"
    exit 1
fi

GRUB_HOME=$1
EFI_HOME=$2

# create a stub grub2 config in EFI
BOOT_UUID=$(grub2-probe --target=fs_uuid "${GRUB_HOME}")
GRUB_DIR=$(grub2-mkrelpath "${GRUB_HOME}")

echo "Generating grub stub config for drive " "${BOOT_UUID}"
echo "GRUB_DIR=" "${GRUB_DIR}"
echo "EFI_HOME=" "${EFI_HOME}"

cat << EOF > "${EFI_HOME}"/grub.cfg.stb
search --no-floppy --root-dev-only --fs-uuid --set=dev ${BOOT_UUID}
set prefix=(\$dev)${GRUB_DIR}
export \$prefix
configfile \$prefix/grub.cfg
EOF

mv ${EFI_HOME}/grub.cfg.stb ${EFI_HOME}/grub.cfg