FM / hooks

/usr/share/initramfs-tools/hooks

Name	Size	Mode	Actions
bcache	543	0755	edit dl rm
btrfs	568	0755	edit dl rm
cloud-initramfs-dyn-netconf	118	0755	edit dl rm
compcache	3633	0755	edit dl rm
console_setup	3142	0755	edit dl rm
copymods	280	0755	edit dl rm
cryptgnupg	921	0755	edit dl rm
cryptgnupg-sc	2242	0755	edit dl rm
cryptkeyctl	424	0755	edit dl rm
cryptopensc	1676	0755	edit dl rm
cryptpassdev	888	0755	edit dl rm
cryptroot	17244	0755	edit dl rm
cryptroot-unlock	637	0755	edit dl rm
dmsetup	506	0755	edit dl rm
fixrtc	436	0755	edit dl rm
framebuffer	579	0755	edit dl rm
fsck	1983	0755	edit dl rm
fuse	230	0755	edit dl rm
iscsi	732	0755	edit dl rm
kbd	301	0755	edit dl rm
klibc-utils	646	0755	edit dl rm
kmod	432	0755	edit dl rm
lvm2	670	0755	edit dl rm
mdadm	2897	0755	edit dl rm
ntfs_3g	304	0755	edit dl rm
overlayroot	732	0755	edit dl rm
plymouth	5873	0755	edit dl rm
resume	3116	0755	edit dl rm
sg3-utils	485	0755	edit dl rm
thermal	1324	0755	edit dl rm
thin-provisioning-tools	369	0755	edit dl rm
udev	1703	0755	edit dl rm
xfs	850	0755	edit dl rm
zz-busybox-initramfs	2233	0755	edit dl rm
zz-dhclient	411	0755	edit dl rm

Edit: /usr/share/initramfs-tools/hooks/resume (3116B)

#!/bin/sh

PREREQ=""

prereqs()
{
	echo "$PREREQ"
}

case $1 in
# get pre-requisites
prereqs)
	prereqs
	exit 0
	;;
esac

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

# First check if a location is set and is a valid swap partition.
# If so, the config file will be copied in and there is nothing to do.
if [ -n "$RESUME" ] && [ "$RESUME" != auto ]; then
	if [ "$RESUME" = none ]; then
		exit 0
	fi
	if resume_dev_node="$(resolve_device "$RESUME")" && \
	   blkid -p -n swap "$resume_dev_node" >/dev/null 2>&1; then
		exit 0
	fi

echo >&2 "W: initramfs-tools configuration sets RESUME=$RESUME"
	echo >&2 "W: but no matching swap device is available."
fi

# If we were not explicitly requested to select a device, or the -v
# option is used, report that we are doing so
report_auto()
{
	test "${verbose?}" != y && test "$RESUME" = auto || echo "I: $*"
}

# Report in excruciating detail if the -v option is used
report_verbose()
{
	test "${verbose?}" != y || echo "I: $*"
}

report_verbose "Configuration sets RESUME=$RESUME"

# Try to autodetect the RESUME partition, using biggest swap device that
# is not ephemeral.  We need to be able to read the listed swap partitions.
resume_auto=
if ! ischroot && [ -r /proc/swaps ]; then
	# shellcheck disable=SC2013
	for resume_auto in $(grep ^/dev/ /proc/swaps | sort -rnk3 | cut -d " " -f 1); do
		report_verbose "Checking swap device $resume_auto"
		ephemeral=false
		dm_name="$(dmsetup info -c --noheadings -o name "$resume_auto" 2>/dev/null)"

# dm-crypt is ephemeral if the key file is /dev/urandom
		if [ -n "$dm_name" ] && [ -e /etc/crypttab ]; then
			report_verbose "$resume_auto has device-mapper name $dm_name; checking crypttab"
			# shellcheck disable=SC2034
			while read -r cryptdev srcdev keyfile junk; do
				report_verbose "Found cryptdev=$cryptdev keyfile=$keyfile"
				if [ "$cryptdev" = "$dm_name" ] && [ "$keyfile" = /dev/urandom ]; then
					report_verbose "Rejecting $resume_auto since it has no permanent key"
					ephemeral=true
				fi
			done < /etc/crypttab
		fi

# zram is ephemeral
		case "$resume_auto" in
		/dev/zram*)
			report_verbose "Rejecting $resume_auto since it is zram"
			ephemeral=true
			;;
		esac

$ephemeral || break
	done

if $ephemeral; then
		resume_auto=
	fi
	if [ -n "$resume_auto" ]; then
		if [ -n "$dm_name" ]; then
			resume_auto_canon="/dev/mapper/$dm_name"
		elif UUID=$(blkid -s UUID -o value "$resume_auto"); then
			resume_auto_canon="UUID=$UUID"
		else
			resume_auto_canon=
		fi
		report_auto "The initramfs will attempt to resume from $resume_auto"
		if [ -n "$resume_auto_canon" ]; then
			report_auto "($resume_auto_canon)"
			resume_auto="$resume_auto_canon"
		fi
		report_auto "Set the RESUME variable to override this."
	fi
fi

# Write selected resume device to intramfs conf.d
if [ "$RESUME" = auto ] || [ -n "$resume_auto" ]; then
	# If we were explicitly requested to select a device, and we failed,
	# report that
	if [ -z "$resume_auto" ]; then
		echo >&2 "W: initramfs-tools failed to select a resume device"
	fi
	echo "RESUME=${resume_auto}" > "${DESTDIR}/conf/conf.d/zz-resume-auto"
fi

cmd: