#!/bin/bash --norc

# Generate an initramfs image that isolates dump capture capability within

# the default initramfs using zz-fadumpinit dracut module.

if [[ -f /etc/sysconfig/kdump ]]; then

	. /etc/sysconfig/kdump

fi

[[ $dracutbasedir ]] || dracutbasedir=/usr/lib/dracut

. $dracutbasedir/dracut-functions.sh

. /lib/kdump/kdump-lib.sh

. /lib/kdump/kdump-logger.sh

#initiate the kdump logger

if ! dlog_init; then

	echo "mkfadumprd: failed to initiate the kdump logger."

	exit 1

fi

MKFADUMPRD_TMPDIR="$(mktemp -d -t mkfadumprd.XXXXXX)"

[ -d "$MKFADUMPRD_TMPDIR" ] || perror_exit "mkfadumprd: mktemp -d -t mkfadumprd.XXXXXX failed."

trap '

    ret=$?;

    [[ -d $MKFADUMPRD_TMPDIR ]] && rm --one-file-system -rf -- "$MKFADUMPRD_TMPDIR";

    exit $ret;

    ' EXIT

# clean up after ourselves no matter how we die.

trap 'exit 1;' SIGINT

MKDUMPRD="/sbin/mkdumprd -f"

# Default boot initramfs to be rebuilt

REBUILD_INITRD="$1" && shift

TARGET_INITRD="$1" && shift

FADUMP_INITRD="$MKFADUMPRD_TMPDIR/fadump.img"

### First build an initramfs with dump capture capability

# this file tells the initrd is fadump enabled

touch "$MKFADUMPRD_TMPDIR/fadump.initramfs"

ddebug "rebuild fadump initrd: $FADUMP_INITRD $DEFAULT_INITRD $KDUMP_KERNELVER"

# Don't use squash for capture image or default image as it negatively impacts

# compression ratio and increases the size of the initramfs image.

# Don't compress the capture image as uncompressed image is needed immediately.

# Also, early microcode would not be needed here.

if ! $MKDUMPRD "$FADUMP_INITRD" -i "$MKFADUMPRD_TMPDIR/fadump.initramfs" /etc/fadump.initramfs --omit squash --no-compress --no-early-microcode; then

	perror_exit "mkfadumprd: failed to build image with dump capture support"

fi

### Unpack the initramfs having dump capture capability retaining previous file modification time.

# This helps in saving space by hardlinking identical files.

mkdir -p "$MKFADUMPRD_TMPDIR/fadumproot"

if ! cpio -id --preserve-modification-time --quiet -D "$MKFADUMPRD_TMPDIR/fadumproot" < "$FADUMP_INITRD"; then

	derror "mkfadumprd: failed to unpack '$MKFADUMPRD_TMPDIR'"

	exit 1

fi

### Pack it into the normal boot initramfs with zz-fadumpinit module

_dracut_isolate_args=(

	--rebuild "$REBUILD_INITRD" --add zz-fadumpinit

	-i "$MKFADUMPRD_TMPDIR/fadumproot" /fadumproot

	-i "$MKFADUMPRD_TMPDIR/fadumproot/usr/lib/dracut/hostonly-kernel-modules.txt"

	/usr/lib/dracut/fadump-kernel-modules.txt

)

# Use zstd compression method, if available

if ! have_compression_in_dracut_args; then

	if is_zstd_command_available; then

		_dracut_isolate_args+=(--compress zstd)

	fi

fi

if ! dracut --force --quiet "${_dracut_isolate_args[@]}" "$@" "$TARGET_INITRD"; then

	perror_exit "mkfadumprd: failed to setup '$TARGET_INITRD' with dump capture capability"

fi