#!/bin/bash

if ! [[ $KERNEL_INSTALL_MACHINE_ID ]]; then
    exit 0
fi

# PV and PVH Xen DomU guests boot with pygrub that doesn't have BLS support,
# also Xen Dom0 use the menuentries from 20_linux_xen and not the ones from
# 10_linux. So BLS support needs to be disabled for both Xen Dom0 and DomU.
if [[ -e /sys/hypervisor/type ]] && grep -q "^xen$" /sys/hypervisor/type; then
    RUN_MKCONFIG=true
    DISABLE_BLS=true
fi

ARCH=$(uname -m)
# Older ppc64le OPAL firmware don't have BLS support so grub2-mkconfig has to
# be run to generate a GRUB config file that contains menuentry commands.
if [[ $ARCH = "ppc64le" ]]; then
    RUN_MKCONFIG=true
fi

if [[ $DISABLE_BLS = "true" ]]; then
    if grep -q '^GRUB_ENABLE_BLSCFG="*true"*\s*$' /etc/default/grub; then
	sed -i 's/^GRUB_ENABLE_BLSCFG=.*/GRUB_ENABLE_BLSCFG=false/' /etc/default/grub
    fi
fi

# A traditional grub configuration file needs to be generated only in the case when
# the bootloaders are not capable of populating a menu entry from the BLS fragments.
if [[ $RUN_MKCONFIG != "true" ]]; then
    exit 0
fi

[[ -f /etc/default/grub ]] && . /etc/default/grub

COMMAND="$1"

case "$COMMAND" in
    add|remove)
        grub2-mkconfig --no-grubenv-update -o /boot/grub2/grub.cfg >& /dev/null
        ;;
    *)
        ;;
esac