#!/bin/sh
# intel-microcode initramfs-tools hook script version 3
# Copyright (C) 2012-2016 Henrique de Moraes Holschuh <hmh@debian.org>
# Released under the GNU GPL v2 or later license
#
# Generates a copy of the Intel microcode (by default tailored to the
# running system), and installs it in the early initramfs.
#
# iucode_tool v1.0 or later is required.
#

PREREQ=""
IUCODE_CONFIG=/etc/default/intel-microcode

prereqs()
{
   echo "$PREREQ"
}

case $1 in
prereqs)
   prereqs
   exit 0
   ;;
esac

. /usr/share/initramfs-tools/hook-functions

verbose()
{
	if [ "${verbose}" = "y" ] ; then
		echo "intel-microcode: $*"
	fi
	:
}

if [ "${verbose}" = "y" ] ; then
	IUCODE_TOOL_OPTIONS="-l"
else
	IUCODE_TOOL_OPTIONS="-q"
fi

IUCODE_TOOL=$(command -v iucode_tool)
if [ -z "${IUCODE_TOOL}" ] && [ -x /usr/sbin/iucode_tool ] ; then
	IUCODE_TOOL=/usr/sbin/iucode_tool
fi

IUCODE_FW_DIR=/usr/lib/firmware/intel-ucode
if [ "$MODULES" = "most" ]; then
	IUCODE_TOOL_INITRAMFS=early
	IUCODE_TOOL_SCANCPUS=no
else
	IUCODE_TOOL_INITRAMFS=auto
	IUCODE_TOOL_SCANCPUS=yes
fi
IUCODE_TOOL_EXTRA_OPTIONS=

[ -r ${IUCODE_CONFIG} ] && . ${IUCODE_CONFIG}

[ -z "${IUCODE_TOOL_INITRAMFS}" ] && IUCODE_TOOL_INITRAMFS=no

case "${IUCODE_TOOL_INITRAMFS}" in
    no|0)
	verbose "intel-microcode: disabled by ${IUCODE_CONFIG}"
	exit 0
	;;
    auto|early)
	;;
    yes|1)
	IUCODE_TOOL_INITRAMFS=early
	echo "W: intel-microcode: initramfs mode not supported, using early initramfs mode" >&2
	;;
    *)
	echo "E: intel-microcode: invalid IUCODE_TOOL_INITRAMFS, using automatic mode" >&2
	IUCODE_TOOL_INITRAMFS=auto
esac

# don't do anything unless there's an Intel processor in the system in auto mode
if [ "${IUCODE_TOOL_INITRAMFS}" = "auto" ] ; then
	grep -q "^vendor_id[[:blank:]]*:[[:blank:]]*.*GenuineIntel" /proc/cpuinfo || {
		verbose "no Intel processors detected, nothing to do"
		exit 0
	}
fi

# we require iucode_tool, but something is broken
if [ ! -x "${IUCODE_TOOL}" ] ; then
	echo "E: intel-microcode: cannot run iucode_tool!" >&2
	exit 0
fi

# Blacklist all kernel versions before v3.10, as they don't support early
# initramfs mode.
#
# This doesn't blacklist early 3.10 kernels in the LTS branches, we don't have
# enough information at the initramfs-tools layer, due to the way Debian and
# Ubuntu version kernel packages.
if dpkg --compare-versions "${version}" lt 3.10 ; then
       echo "E: intel-microcode: unsupported kernel version!" >&2
       exit 0
fi

if [ "${IUCODE_TOOL_SCANCPUS}" != "yes" ] ; then
	verbose "adding microcode for either all or selected Intel processor models"
else
	verbose "adding microcode for currently online and selected Intel processors"
	grep -q cpu/cpuid /proc/devices || modprobe -q cpuid
	IUCODE_TOOL_OPTIONS="${IUCODE_TOOL_OPTIONS} --scan-system"
fi

# paranoia
[ -z "${DESTDIR}" ] && {
	echo "E: intel-microcode: DESTDIR empty!" >&2
	exit 1
}
[ -z "${IUCODE_FW_DIR}" ] && {
	echo "E: intel-microcode: IUCODE_FW_DIR empty!" >&2
	exit 1
}

# include the microcode module in the initramfs for logging purposes, but
# ensure it will have no microcode data files to load.  This is also a safety
# net: we don't want it to be acidentally loaded outside the initramfs.
#
# This shouldn't be expensive, as the in-kernel firmware loader is quite
# fast at detecting missing data files and doesn't wait for them.
#
# note: force_load will load a blacklisted module. We depend on that behavior.
#
# For 4.4 and later kernels, the microcode driver cannot be a module and will
# be built-in.
dpkg --compare-versions "${version}" lt 4.4 && {
    [ -d "${DESTDIR}${IUCODE_FW_DIR}" ] && rm -fr "${DESTDIR}${IUCODE_FW_DIR}"

    manual_add_modules microcode && {
        # force_load has broken semanthics when the .ko file is missing
        find "${DESTDIR}/${MODULESDIR}" -type f -print | grep -qc '/microcode\.ko$' && {
            verbose "modular microcode driver detected"
            force_load microcode
        }
    }
}

# generate early initramfs image and prepend
verbose "using early initramfs microcode update mode..."
EFW=$(mktemp "${TMPDIR:-/var/tmp}/mkinitramfs-EFW_XXXXXXXXXX") || {
	echo "E: intel-microcode: cannot create temporary file" >&2
	exit 1
    }
( find /usr/share/misc -maxdepth 1 -type f -name 'intel-microcode*' -print0 ;
  find "${IUCODE_FW_DIR}" -maxdepth 0 -type d -print0 ) 2>/dev/null \
| xargs -0 -r -x ${IUCODE_TOOL} ${IUCODE_TOOL_OPTIONS} \
		--write-earlyfw="${EFW}" --overwrite \
		${IUCODE_TOOL_EXTRA_OPTIONS} \
&& prepend_earlyinitramfs "${EFW}" && {
	rm "${EFW}"
	exit 0
}

# usually we get here when initramfs-tools is missing prepend_earlyinitramfs()
# or when iucode_tool does not support --write-earlyfw, i.e. when old versions
# of these tools are installed.

rm "${EFW}" || true

echo "E: intel-microcode: failed to create or prepend the early initramfs to the initramfs" >&2

: