Resume Hook (Hibernation)

README.md

@@ -11,6 +11,7 @@ Tiny initramfs written in POSIX shell
 - ZFS + native encryption support
 - LUKS (detached header, key), LVM
 - mdev, mdevd, eudev, systemd-udevd
+- Resume from swap partition
 
 ## Dependencies
 

doc/tinyramfs.5

@@ -144,6 +144,14 @@ lvm_tag
 The tag of your LVM logical volume.\&
 .P
 .RE
+.SS RESUME
+.P
+resume
+.P
+.RS 4
+The location of your swap partition.\&
+.P
+.RE
 .SS ZFS
 .P
 zfs_key

doc/tinyramfs.5.scd

@@ -103,6 +103,12 @@ lvm_tag
 
 	The tag of your LVM logical volume.
 
+## RESUME
+
+resume
+
+	The location of your swap partition.
+
 ## ZFS
 
 zfs_key

hook/resume/resume

@@ -0,0 +1,8 @@
+# vim: set ft=sh:
+# shellcheck shell=sh
+#
+# https://shellcheck.net/wiki/SC2154
+# shellcheck disable=2154
+
+copy_exec readlink
+copy_exec cat

hook/resume/resume.init

@@ -0,0 +1,14 @@
+# vim: set ft=sh:
+# shellcheck shell=sh
+#
+# https://shellcheck.net/wiki/SC2154
+# shellcheck disable=2154
+
+resolve_device "$resume"
+
+if [ -n "$device" ]; then
+	dev_link=$(readlink "$device")
+
+	cat /sys/class/block/"${dev_link##*/}"/dev > /sys/power/resume || \
+	panic "failed to resume"
+fi