#!/bin/bash

# Configure grub. Note that the various conditionals here are to handle
# different distributions gracefully.

set -e
set -x

install-packages grub-pc

# XXX: grub-probe on the nbd0/loop0 device returns nothing - workaround, manually
# specify modules. https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/1073731
GRUBNAME=`which grub-install` || echo "trying grub2-install"
if [ -z "$GRUBNAME" ]; then
    GRUBNAME="bash -x `which grub2-install`"
fi
if [ -z "$GRUBNAME" ]; then
    echo "NO grub-install or grub2-install found"
    exit 1
fi
# FIXME:
[ -n "$IMAGE_BLOCK_DEVICE" ]
PART_DEV=$IMAGE_BLOCK_DEVICE
BOOT_DEV=$(echo $IMAGE_BLOCK_DEVICE | sed -e 's/p1//')
GRUB_OPTS=${GRUB_OPTS:""}
# XXX: This is buggy:
# - --target=i386-pc is invalid for non-i386/amd64 architectures
# - and for UEFI too.
#    GRUB_OPTS="$GRUB_OPTS --target=i386-pc"
if [[ ! $GRUB_OPTS == *--target* ]]; then
  # /sys/ comes from the host machine. If the host machine is using EFI
  # but the image being built doesn't have EFI boot-images installed we
  # should set the --target to use a BIOS-based boot-image.
  #
  # * --target tells grub what's the target platform
  # * the boot images are placed in /usr/lib/grub/<cpu>-<platform>
  # * i386-pc is used for BIOS-based machines
  # http://www.gnu.org/software/grub/manual/grub.html#Installation
  #
  if [ -d /sys/firmware/efi ]; then
    if [ ! -d /usr/lib/grub/*-efi ]; then
      case $ARCH in
        "x86_64"|"amd64")
           GRUB_OPTS="$GRUB_OPTS --target=i386-pc"
          ;;
        "i386")
           target=i386-pc
           if [ -e /proc/device-tree ]; then
             for x in /proc/device-tree/*; do
               if [ -e "$x" ]; then
                 target="i386-ieee1275"
               fi
             done
           fi
           GRUB_OPTS="$GRUB_OPTS --target=$target"
          ;;
      esac
    fi
  fi
fi

$GRUBNAME --modules="biosdisk part_msdos" $GRUB_OPTS $BOOT_DEV

# This might be better factored out into a per-distro 'install-bootblock'
# helper.
if [ -f "/boot/grub/grub.cfg" ] ; then
  GRUB_CFG=/boot/grub/grub.cfg
elif [ -f "/boot/grub2/grub.cfg" ] ; then
  GRUB_CFG=/boot/grub2/grub.cfg
fi

# If GRUB configuration file does not exist, generate one
if [ ! $GRUB_CFG ]; then
  if [ -d /boot/grub2 ]; then
    GRUB_CFG=/boot/grub2/grub.cfg
  elif [ -d /boot/grub ]; then
    GRUB_CFG=/boot/grub/grub.cfg
  fi
  grub2-mkconfig -o $GRUB_CFG
fi;

DIST=`lsb_release -is`
[ -n "$DIST" ]
RELEASE=`lsb_release -cs`
[ -n "$RELEASE" ]
# grub-mkconfig generates a config with the device in it,
# This shouldn't be needed, but old code has bugs
if [ $RELEASE = 'precise' ] ; then
  # Replace the search attempt with a hardcoded root as the Ubuntu reference
  # images use.
  sed -i "s%search --no.*%%" $GRUB_CFG
  sed -i "s%set root=.*%set root=(hd0,1)%" $GRUB_CFG
fi
# force use of a LABEL:
# NOTE: Updating the grub config by hand once deployed should work, its just
# prepping it in a different environment that needs fiddling.
sed -i "s%$PART_DEV%LABEL=cloudimg-rootfs%" $GRUB_CFG
sed -i "s%search --no-floppy --fs-uuid --set=root .*$%search --no-floppy --set=root --label cloudimg-rootfs%" $GRUB_CFG
sed -i "s%root=UUID=[A-Za-z0-9\-]*%root=LABEL=cloudimg-rootfs%" $GRUB_CFG
if [ $DIST = 'Fedora' ] ; then
  # enable serial console
  sed -i "s%LABEL=cloudimg-rootfs%LABEL=cloudimg-rootfs console=tty0 console=ttyS0,115200%" $GRUB_CFG
fi