#!/bin/bash
#BLURB="Generate an initrd for the kernel"

# If KERNEL is defined already, we'll use that.
# Otherwise we'll use the value for KERNEL in /etc/default/geninitrd, if it
# is defined there.
# Otherwise we'll use the newest kernel we find in /boot.

# Do we already have a value defined for KERNEL? If so, make sure that we
# use it:
if [ ! -z "$KERNEL" ]; then
  KERNEL_OVERRIDE=$KERNEL
fi

# Load defaults:
if [ -r etc/default/geninitrd ]; then
  . etc/default/geninitrd
fi

# Populate any unset options (when not called from the installer):
if [ -z "$INSIDE_INSTALLER" ]; then
  KERNEL=${KERNEL:-/boot/vmlinuz-generic}
  GENINITRD_NAMED_SYMLINK=${GENINITRD_NAMED_SYMLINK:-true}
  GENINITRD_INITRD_GZ_SYMLINK=${GENINITRD_INITRD_GZ_SYMLINK:-true}
  GENERATOR=${GENERATOR:-mkinitrd}
  DRACUT_OPTS=${DRACUT_OPTS:-"--force --hostonly"}
  AUTOGENERATE_INITRD=${AUTOGENERATE_INITRD:-true}
  AUTO_REMOVE_ORPHANED_INITRDS=${AUTO_REMOVE_ORPHANED_INITRDS:-true}
  AUTO_UPDATE_GRUB=${AUTO_UPDATE_GRUB:-true}
  GENINITRD_DIALOG=${GENINITRD_DIALOG:-false}
  GENINITRD_COMMAND_OUTPUT=${GENINITRD_COMMAND_OUTPUT:-true}
else # these are the defaults when called from the installer:
  KERNEL=/boot/vmlinuz-generic
  GENINITRD_NAMED_SYMLINK=true
  GENINITRD_INITRD_GZ_SYMLINK=true
  GENERATOR=mkinitrd
  DRACUT_OPTS="--force --hostonly"
  AUTOGENERATE_INITRD=true
  AUTO_REMOVE_ORPHANED_INITRDS=true
  AUTO_UPDATE_GRUB=true
  GENINITRD_DIALOG=true
  GENINITRD_COMMAND_OUTPUT=false
fi

# If we have a KERNEL_OVERRIDE, set KERNEL to this value:
if [ ! -z "$KERNEL_OVERRIDE" ]; then
  KERNEL=$KERNEL_OVERRIDE
fi

# If this is disabled, exit:
if [ "$KERNEL_DOINST" = "true" -a "$AUTOGENERATE_INITRD" = "false" ]; then
  exit 0
fi

if [ -z "$KERNEL" ]; then
  # If we weren't told anything else, then use the newest kernel:
  KERNEL="$(find /boot -name "vmlinuz-*" -type f | xargs ls -t | head -n 1)"
fi

# If we don't see $KERNEL, try looking in /boot:
if [ ! -r $KERNEL ]; then
  if [ -r boot/$KERNEL ]; then
    KERNEL=boot/$KERNEL
  fi
fi

# In case this is a symlink, get the real file:
KERNEL="$(readlink -f $KERNEL)"

# Find the kernel version:
if [ -r $KERNEL ]; then
  if file $KERNEL | grep -wq "Linux kernel" ; then
    KERNEL_VERSION=$(strings $KERNEL | grep '([^ ]*@[^ ]*) #' | cut -f1 -d' ')
  else
    echo "error: $KERNEL is not a Linux kernel."
    exit 1
  fi 
else
  if [ -z "$KERNEL" ]; then
    echo "error: was not given a KERNEL to make an initrd."
    exit 1
  else
    echo "error: KERNEL=$KERNEL was not found."
    exit 1
  fi
fi

# Sometimes mkinitrd_command_generator.sh does not detect LVM properly. Until I
# get to the bottom of that, it's safer to just always include LVM support.
LVM_OPTION="-L"
# Ditto on RAID:
RAID_OPTION="-R"

# If we asked for mkinitrd, but do not have /etc/mkinitrd.conf, then fall
# back on mkinitrd_command_generator.sh instead:
if [ "$GENERATOR" = "mkinitrd" -a ! -r etc/mkinitrd.conf ]; then
  GENERATOR=mkinitrd_command_generator.sh
fi

# If the GENERATOR does not exist, this is obviously a fatal error:
if [ "$GENERATOR" = "mkinitrd_command_generator.sh" -a ! -x /usr/share/mkinitrd/mkinitrd_command_generator.sh ]; then
  echo "error: GENERATOR mkinitrd_command_generator.sh not found."
  exit 1
elif [ "$GENERATOR" = "mkinitrd" -a ! -x /sbin/mkinitrd ]; then
  echo "error: GENERATOR mkinitrd not found."
  exit 1
elif [ "$GENERATOR" = "dracut" -a ! -x /usr/bin/dracut ]; then
  echo "error: GENERATOR dracut not found."
  exit 1
fi

# Generate the initrd:
if [ "$GENINITRD_DIALOG" = "true" ]; then
  dialog --title "GENERATING INITIAL RAMDISK" --infobox \
  "Generating an initial ramdisk for use with the $KERNEL_VERSION kernel (using $GENERATOR). \
The initial ramdisk contains kernel modules needed to mount the \
root partition, and must be regenerated whenever the kernel is updated. To \
regenerate the initrd, select this setup script from within pkgtool, or run \
'geninitrd' which will produce an initial ramdisk \
(/boot/initrd-${KERNEL_VERSION}.img) for the installed kernel." 0 0
elif [ "$GENINITRD_COMMAND_OUTPUT" = "true" ]; then
  echo "Generating /boot/initrd-${KERNEL_VERSION}.img for use with"
  echo "the $KERNEL_VERSION kernel (using $GENERATOR):"
fi

if [ "$GENERATOR" = "mkinitrd_command_generator.sh" ]; then
  if [ "$GENINITRD_COMMAND_OUTPUT" = "true" ]; then
    chroot . /usr/share/mkinitrd/mkinitrd_command_generator.sh -k $KERNEL_VERSION -a "$LVM_OPTION $RAID_OPTION -o /boot/initrd-${KERNEL_VERSION}.img" | chroot . bash
  else
    chroot . /usr/share/mkinitrd/mkinitrd_command_generator.sh -k $KERNEL_VERSION -a "$LVM_OPTION $RAID_OPTION -o /boot/initrd-${KERNEL_VERSION}.img" | chroot . bash 1> /dev/null 2> /dev/null
  fi
elif [ "$GENERATOR" = "mkinitrd" ]; then
  if [ "$GENINITRD_COMMAND_OUTPUT" = "true" ]; then
    chroot . /sbin/mkinitrd -F /etc/mkinitrd.conf -k $KERNEL_VERSION -o /boot/initrd-${KERNEL_VERSION}.img
  else
    chroot . /sbin/mkinitrd -F /etc/mkinitrd.conf -k $KERNEL_VERSION -o /boot/initrd-${KERNEL_VERSION}.img 1> /dev/null 2> /dev/null
  fi
elif [ "$GENERATOR" = "dracut" ]; then
  if [ "$GENINITRD_COMMAND_OUTPUT" = "true" ]; then
    chroot . /usr/bin/dracut $DRACUT_OPTS /boot/initrd-${KERNEL_VERSION}.img $KERNEL_VERSION
  else
    chroot . /usr/bin/dracut $DRACUT_OPTS /boot/initrd-${KERNEL_VERSION}.img $KERNEL_VERSION 1> /dev/null 2> /dev/null
  fi
else
  echo "error: no handler for GENERATOR=$GENERATOR"
  echo "Unable to generate /boot/initrd-${KERNEL_VERSION}.img."
  exit 1
fi

if [ "$GENINITRD_NAMED_SYMLINK" = "true" ]; then
  # Make initrd symlinks for all matching kernel symlinks:
  ( cd boot
    for symlink in $(find . -type l -name "vmlinuz-*") ; do
      SYMLINK_VERSION=$(strings $symlink | grep '([^ ]*@[^ ]*) #' | cut -f1 -d' ')
      if [ "$SYMLINK_VERSION" = "$KERNEL_VERSION" ]; then
        KERNEL_NAME="$(echo $symlink | cut -f 2- -d -)"
        rm -f initrd-${KERNEL_NAME}.img
        ln -sf initrd-${KERNEL_VERSION}.img initrd-${KERNEL_NAME}.img
        if [ "$GENINITRD_COMMAND_OUTPUT" = "true" ]; then
          echo "Created named symlink: /boot/initrd-${KERNEL_NAME}.img -> initrd-${KERNEL_VERSION}.img"
        fi
      fi
    done
  )
fi

if [ "$GENINITRD_INITRD_GZ_SYMLINK" = "true" ]; then
  ( cd boot
    rm -f initrd.gz
    ln -sf initrd-${KERNEL_VERSION}.img initrd.gz
    if [ "$GENINITRD_COMMAND_OUTPUT" = "true" ]; then
      echo "Created initrd.gz symlink: /boot/initrd.gz -> initrd-${KERNEL_VERSION}.img"
    fi
  )
fi

# If enabled in /etc/default/geninitrd, remove any orphaned initrds
# after generating the initrd:
if [ "$AUTO_REMOVE_ORPHANED_INITRDS" = "true" ]; then
  if [ "$GENINITRD_COMMAND_OUTPUT" = "true" ]; then
    chroot . /usr/sbin/remove-orphaned-initrds
  else
    chroot . /usr/sbin/remove-orphaned-initrds 1> /dev/null 2> /dev/null
  fi
fi

if [ "$AUTO_UPDATE_GRUB" = "true" ]; then
  if [ "$GENINITRD_COMMAND_OUTPUT" = "true" ]; then
    # Filter out bogus warnings from libdevmapper that could be triggered
    # by upgradepkg's use of flock:
    echo "Running /usr/sbin/update-grub (please wait)..."
    chroot . /usr/sbin/update-grub |& grep -v "File descriptor"
  else
    chroot . /usr/sbin/update-grub 1> /dev/null 2> /dev/null
  fi
fi