#!/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 (petitboot version < 1.8.0) don't have BLS support
# so grub2-mkconfig has to be run to generate a config with menuentry commands.
if [[ $ARCH = "ppc64le" ]] && [ -d /sys/firmware/opal ]; then

    petitboot_path="/sys/firmware/devicetree/base/ibm,firmware-versions/petitboot"

    if test -e ${petitboot_path}; then
        read -r -d '' petitboot_version < ${petitboot_path}
        petitboot_version="$(echo ${petitboot_version//v})"
        major_version="$(echo ${petitboot_version} | cut -d . -f1)"
        minor_version="$(echo ${petitboot_version} | cut -d . -f2)"

        if test -z ${petitboot_version} || test ${major_version} -lt 1 || \
           test ${major_version} -eq 1 -a ${minor_version} -lt 8; then
            RUN_MKCONFIG=true
        fi
    else
        RUN_MKCONFIG=true
    fi
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

[ -f /etc/default/grub ] && . /etc/default/grub
if [ x$GRUB_ENABLE_BLSCFG = xfalse ]; then
   RUN_MKCONFIG=true
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

COMMAND="$1"

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