#!/usr/bin/env bash

##
## grub-mkconfig helper script specific to Arch Linux
## Contributed by "Keshav Amburay" <the ddoott ridikulus ddoott rat aatt geemmayil ddoott ccoomm>
## Updated on 08 February 2014
##
## Script based on do_grub_config() function in Arch Linux Archboot ISO Installer/Setup script 
## Some parts taken from /etc/grub.d/10_linux script shipped by GRUB(2) upstream
##
## This script can be freely distributed and/or modified 
## under the terms of the GNU General Public License as published by
## the Free Software Foundation, either version 3 of the License, or
## (at your option) any later version.
##
## This script is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
## GNU General Public License for more details.
##

## Adapted for use with the xen AUR package, to ensure feature comparity
## Modified by "David Sutton" <kantras - gmail com>

_FUNC_GRUB_FILE_PRESENT() {
    
    [[ -z "${GRUB_PLATFORM}" ]] && GRUB_PLATFORM="x86"
    
    if [[ "${GRUB_PLATFORM}" == "x86" ]]; then
        check="--is-x86-linux32"
    elif [[ "${GRUB_PLATFORM}" == "i386-xen-pae" ]]; then
        check="--is-i386-xen-pae-domu"
    elif [[ "${GRUB_PLATFORM}" == "x86_64-xen" ]]; then
        check="--is-x86_64-xen-domu"
    else
        check="--is-${GRUB_PLATFORM}-linux"
    fi
    
    case "${GRUB_PLATFORM}" in
        x86)
            list="$(for i in "${GRUB_ROOT}"/boot/vmlinuz-linux* ; do
                        if grub_file_is_not_garbage "${i}" && "${grub_file}" ${check} "${i}" ; then echo -n "${i} " ; fi
                    done)" ;;
        *) 
          list="$(for i in "${GRUB_ROOT}"/boot/vmlinuz-linux* ; do
                      if grub_file_is_not_garbage "${i}" && "${grub_file}" ${check} "${i}" ; then echo -n "${i} " ; fi
                  done)" ;;
    esac
}

set -e

prefix="/usr"
exec_prefix="${prefix}"
datarootdir="/usr/share"
datadir="${datarootdir}"
sysconfdir="/etc"

. "${datarootdir}/grub/grub-mkconfig_lib"

. "${sysconfdir}/default/grub"

export XEN_HYPERVISOR_CMDLINE="xsave=1"
export XEN_LINUX_CMDLINE="console=tty0"

[[ -r "${sysconfdir}/xen/grub.conf" ]] && . "${sysconfdir}/xen/grub.conf"

[[ -z "${XEN_LINUX_CMDLINE_OVERRIDE}" ]] && XEN_LINUX_CMDLINE_OVERRIDE="0"

export TEXTDOMAIN="grub"
export TEXTDOMAINDIR="${datarootdir}/locale"

CLASS="--class xen --class arch-linux --class arch --class gnu-linux --class gnu --class os"

[[ "${grub_file}" != "" ]] && _FUNC_GRUB_FILE_PRESENT

BOOT_PART_FS_UUID="$(${grub_probe} --target="fs_uuid" "/boot" 2>/dev/null)"
BOOT_PART_HINTS_STRING="$(${grub_probe} --target="hints_string" "/boot" 2>/dev/null || true)"
BOOT_PART_FS="$(${grub_probe} --target="fs" "/boot" 2>/dev/null)"

ROOT_PART_GRUB_DEVICE="$(${grub_probe} --target=device / || true)"
ROOT_PART_FS="$(${grub_probe} --device ${ROOT_PART_GRUB_DEVICE} --target=fs 2> /dev/null || echo "unknown")"

if [[ "${GRUB_LINUX_ROOT_DEVICE}" == "" ]]; then
    
    case "${ROOT_PART_FS}" in
        btrfs)
            rootsubvol="$(make_system_path_relative_to_its_root /)"
            rootsubvol="${rootsubvol#/}"
            if [[ "${rootsubvol}" != "" ]]; then
                GRUB_LINUX_ROOT_DEVICE="subvol=${rootsubvol}"
            fi
        ;;
        zfs)
            rpool="$(${grub_probe} --device ${GRUB_DEVICE} --target=fs_label 2>/dev/null || true)"
            bootfs="$(make_system_path_relative_to_its_root / | sed -e "s,@$,,")"
            GRUB_LINUX_ROOT_DEVICE="ZFS=${rpool}${bootfs}"
        ;;
    esac
    
    if [[ "${GRUB_DEVICE_UUID}" == "" ]] || \
       [[ "${GRUB_DISABLE_LINUX_UUID}" == "true" ]] || \
       [[ ! -e "/dev/disk/by-uuid/${GRUB_DEVICE_UUID}" ]] || \
       uses_abstraction "${GRUB_DEVICE}" lvm ; then
           GRUB_LINUX_ROOT_DEVICE="${GRUB_DEVICE}"
    else
       GRUB_LINUX_ROOT_DEVICE="UUID=${GRUB_DEVICE_UUID}"
    fi
fi

[[ "${GRUB_LINUX_PARAMS}" == "" ]] && GRUB_LINUX_PARAMS="${GRUB_CMDLINE_LINUX} ${GRUB_CMDLINE_LINUX_DEFAULT}"
if [[ "${XEN_LINUX_CMDLINE_OVERRIDE}" == "0" ]]; then
    GRUB_LINUX_PARAMS="${GRUB_LINUX_PARAMS} ${XEN_LINUX_CMDLINE}"
else
    GRUB_LINUX_PARAMS="${XEN_LINUX_CMDLINE}"
fi

xen_list=`for i in /boot/xen-*.gz /xen-*.gz ; do
       if grub_file_is_not_garbage "$i" ; then echo -n "$i "; fi
done`

while [ "x$xen_list" != "x" ] ; do
    xen=`version_find_latest $xen_list`
    echo "Found Xen hypervisor image: $xen" >&2
    XEN_BASENAME=`basename $xen`
    XEN_VERSION=`echo $XEN_BASENAME | sed -e "s,^[^0-9]*-,,g" | sed -e "s,.gz,,g"`

    for _KERNEL_ in ${list} ; do
    
        echo "Found linux image: ${_KERNEL_}" >&2
    
        basename="$(basename "${_KERNEL_}")"
        dirname="$(dirname "${_KERNEL_}")"
        REAL_DIR="$(make_system_path_relative_to_its_root "${dirname}")"
  
        _KERNEL_FILE_="$(echo ${_KERNEL_} | sed 's,/boot/,,g')"
        _KERNEL_PKG_="pkg-$(echo ${_KERNEL_FILE_} | sed 's,vmlinuz-,,g')"
    
        _INITRAMFS_="${_KERNEL_FILE_/vmlinuz-/initramfs-}.img"
    
        if [[ -e "/boot/${_INITRAMFS_}" ]]; then
    
            echo "Found initramfs image: /boot/${_INITRAMFS_}" >&2
    
            cat << EOF

menuentry "Xen ${XEN_VERSION} / Arch Linux ${_KERNEL_PKG_} kernel" ${CLASS} {
    $(save_default_entry)
    if [ x\$feature_all_video_module = xy ]; then
        insmod all_video
    fi
    set gfxpayload=keep
    insmod ${BOOT_PART_FS}
    if [ x\$feature_platform_search_hint = xy ]; then
        search --no-floppy --fs-uuid  --set=root ${BOOT_PART_HINTS_STRING} ${BOOT_PART_FS_UUID}
    else
        search --no-floppy --fs-uuid  --set=root ${BOOT_PART_FS_UUID}
    fi
    echo '$(printf "Loading Xen %s ..." ${XEN_VERSION})'
    multiboot2 ${REAL_DIR}/${XEN_BASENAME} ${REAL_DIR}/${XEN_BASENAME} ${XEN_HYPERVISOR_CMDLINE}
    echo 'Loading Arch Linux ${_KERNEL_PKG_} kernel ...'
    module2 ${REAL_DIR}/${_KERNEL_FILE_} ${REAL_DIR}/${_KERNEL_FILE_} root=${GRUB_LINUX_ROOT_DEVICE} rw ${GRUB_LINUX_PARAMS}
    echo 'Loading Arch Linux ${_KERNEL_PKG_} kernel initramfs ...'
    module2 ${REAL_DIR}/${_INITRAMFS_}
}

EOF
        fi
    
        _INITRAMFS_FALLBACK_="${_KERNEL_FILE_/vmlinuz-/initramfs-}-fallback.img"
    
        if [[ -e "/boot/${_INITRAMFS_FALLBACK_}" ]]; then
    
            echo "Found fallback initramfs image: /boot/${_INITRAMFS_FALLBACK_}" >&2
    
            cat << EOF

menuentry "Xen ${XEN_VERSION} / Arch Linux ${_KERNEL_PKG_} kernel (fallback initramfs)" ${CLASS} {
    $(save_default_entry)
    if [ x\$feature_all_video_module = xy ]; then
        insmod all_video
    fi
    set gfxpayload=keep
    insmod ${BOOT_PART_FS}
    if [ x\$feature_platform_search_hint = xy ]; then
        search --no-floppy --fs-uuid  --set=root ${BOOT_PART_HINTS_STRING} ${BOOT_PART_FS_UUID}
    else
        search --no-floppy --fs-uuid  --set=root ${BOOT_PART_FS_UUID}
    fi
    echo '$(printf "Loading Xen %s ..." ${XEN_VERSION})'
    multiboot2 ${REAL_DIR}/${XEN_BASENAME} ${REAL_DIR}/${XEN_BASENAME} ${XEN_HYPERVISOR_CMDLINE}
    echo 'Loading Arch Linux ${_KERNEL_PKG_} kernel ...'
    module2 ${REAL_DIR}/${_KERNEL_FILE_} ${REAL_DIR}/${_KERNEL_FILE_} root=${GRUB_LINUX_ROOT_DEVICE} rw ${GRUB_LINUX_PARAMS}
    echo 'Loading Arch Linux ${_KERNEL_PKG_} kernel fallback initramfs ...'
    module2 ${REAL_DIR}/${_INITRAMFS_FALLBACK_}
}

EOF
        fi
    
        if [[ ! -e "/boot/${_INITRAMFS_}" ]] && [[ ! -e "/boot/${_INITRAMFS_FALLBACK_}" ]]; then
            cat << EOF

menuentry "Xen ${XEN_VERSION} / Arch Linux ${_KERNEL_PKG_} kernel (no initramfs)" ${CLASS} {
    $(save_default_entry)
    if [ x\$feature_all_video_module = xy ]; then
        insmod all_video
    fi
    set gfxpayload=keep
    insmod ${BOOT_PART_FS}
    if [ x\$feature_platform_search_hint = xy ]; then
        search --no-floppy --fs-uuid  --set=root ${BOOT_PART_HINTS_STRING} ${BOOT_PART_FS_UUID}
    else
        search --no-floppy --fs-uuid  --set=root ${BOOT_PART_FS_UUID}
    fi
    echo '$(printf "Loading Xen %s ..." ${XEN_VERSION})'
    multiboot2 ${REAL_DIR}/${XEN_BASENAME} ${REAL_DIR}/${XEN_BASENAME} ${XEN_HYPERVISOR_CMDLINE}
    echo 'Loading Arch Linux ${_KERNEL_PKG_} kernel ...'
    module2 ${REAL_DIR}/${_KERNEL_FILE_} ${REAL_DIR}/${_KERNEL_FILE_} root=${GRUB_LINUX_ROOT_DEVICE} rw ${GRUB_LINUX_PARAMS}
}

EOF
        fi
    
    done

    xen_list=`echo $xen_list | tr ' ' '\n' | grep -vx $xen | tr '\n' ' '`
done