FM / hooks

/usr/share/initramfs-tools/hooks

Name	Size	Mode	Actions
amd64_microcode	3856	0755	edit dl rm
bcache	543	0755	edit dl rm
btrfs	701	0755	edit dl rm
cloud-initramfs-dyn-netconf	118	0755	edit dl rm
console_setup	3142	0755	edit dl rm
copymods	280	0755	edit dl rm
cryptgnupg	958	0755	edit dl rm
cryptgnupg-sc	2242	0755	edit dl rm
cryptkeyctl	457	0755	edit dl rm
cryptopensc	1518	0755	edit dl rm
cryptpassdev	888	0755	edit dl rm
cryptroot	15360	0755	edit dl rm
cryptroot-unlock	1010	0755	edit dl rm
dmsetup	506	0755	edit dl rm
fixrtc	436	0755	edit dl rm
framebuffer	579	0755	edit dl rm
fsck	2109	0755	edit dl rm
fuse	231	0755	edit dl rm
intel_microcode	4944	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
linux-firmware	865	0755	edit dl rm
lvm2	691	0755	edit dl rm
mdadm	2975	0755	edit dl rm
ntfs_3g	304	0755	edit dl rm
overlayroot	732	0755	edit dl rm
plymouth	5823	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	1890	0755	edit dl rm
xfs	850	0755	edit dl rm
zz-busybox-initramfs	2233	0755	edit dl rm
zz-dhclient	478	0755	edit dl rm

Edit: /usr/share/initramfs-tools/hooks/udev (1890B)

#!/bin/sh -e

PREREQS=""

prereqs() { echo "$PREREQS"; }

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

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

mkdir -p "$DESTDIR/lib/systemd"
copy_exec /lib/systemd/systemd-udevd      /lib/systemd
copy_exec /bin/udevadm    /bin

mkdir -p "$DESTDIR/etc/udev"
cp -p /etc/udev/udev.conf "$DESTDIR/etc/udev/"

# copy hwdb.bin
if [ -e /usr/lib/udev/hwdb.bin ]; then
    mkdir -p "$DESTDIR/usr/lib/udev"
    cp -p /usr/lib/udev/hwdb.bin "$DESTDIR/usr/lib/udev/hwdb.bin"
fi

# copy .link files containing interface naming definitions
mkdir -p "$DESTDIR/lib/systemd/network/"
find -L /lib/systemd/network -name '*.link' -execdir cp -pt "$DESTDIR/lib/systemd/network/" '{}' +
if [ -d /etc/systemd/network ]; then
  find -L /etc/systemd/network -name '*.link' -execdir cp -pt "$DESTDIR/lib/systemd/network/" '{}' +
fi

mkdir -p "$DESTDIR/lib/udev/rules.d/"
for rules in 50-firmware.rules 50-udev-default.rules \
        60-block.rules 60-persistent-storage.rules \
        61-persistent-storage-android.rules 71-seat.rules \
        73-special-net-names.rules 75-net-description.rules \
        80-net-setup-link.rules 80-drivers.rules; do
  if   [ -e /etc/udev/rules.d/$rules ]; then
    cp -p /etc/udev/rules.d/$rules "$DESTDIR/lib/udev/rules.d/"
  elif [ -e /lib/udev/rules.d/$rules ]; then
    cp -p /lib/udev/rules.d/$rules "$DESTDIR/lib/udev/rules.d/"
  fi
done

# now copy all custom udev rules which don't have an equivalent in /lib (e. g.
# 70-persistent-net.rules or similar); They might contain network names or
# other bits which are relevant for the initramfs.
for rules in /etc/udev/rules.d/*.rules; do
  if [ -e "$rules" ] && [ ! -e "/lib/${rules#/etc/}" ]; then
    cp -p "$rules" "$DESTDIR/lib/udev/rules.d/"
  fi
done

for program in ata_id scsi_id; do
  copy_exec /lib/udev/$program /lib/udev
done
copy_exec /sbin/blkid /sbin

cmd: