#!/bin/sh

set -e

COMMAND="$1"
KVER="$2"

ESP_MOUNTPOINT=/boot/efi
EFI_DIR="$ESP_MOUNTPOINT/qubes"

if [ ! -d "$EFI_DIR" ]; then
    # non-EFI system
    exit 0;
fi

case "$COMMAND" in
    add)
        # take the default section and use it as a template for the new entry
        awk -F = --assign "kver=${KVER}" '
          /^\[/ {
              # section header - previous section (if any) ended

              # if default section already processed, that is all
              if (in_default) exit;
              in_global=0; 
              in_default=0; 
          } 
          /\[global\]/ { 
              in_global=1; 
          }
          /^\[/ {
              if ("[" default_name "]" == $0) {
                  in_default=1;
                  print "[" kver "]";
                  next;
              }
          }
          /^default=/ {
              if (in_global)
                  default_name=$2;
          }
          /^kernel=/ {
              if (in_default) {
                  sub("=[^ ]*", "=vmlinuz-" kver);
              }
          }
          /^ramdisk=/ {
              if (in_default) {
                  sub("=[^ ]*", "=initramfs-" kver ".img");
              }
          }
          {
              if (in_default) {
                  print;
              }
          }' $EFI_DIR/xen.cfg >> $EFI_DIR/xen.cfg
        
        # then change the default
        sed -e "s/default=.*/default=$KVER/" -i $EFI_DIR/xen.cfg

        dracut -f "$EFI_DIR/initramfs-${KVER}.img" "$KVER"
        ;;
    remove)
        # don't care about changing default= line - yum should prevent removing
        # currently running kernel
        awk -F = --assign "kver=${KVER}" '
          /^\[/ {
              # section header - previous section (if any) ended

              in_current=0; 
          } 
          /^\[/ {
              if ($0 == "[" kver "]")
                  in_current=1;
          }
          {
              if (!in_current) {
                  print;
              }
          }' $EFI_DIR/xen.cfg > $EFI_DIR/xen.cfg.new
          mv $EFI_DIR/xen.cfg.new $EFI_DIR/xen.cfg
        rm -f "$EFI_DIR/initramfs-${KVER}.img"
        ;;
esac