From de2d6aea4dfe1b284ed0d485f0acd16303ff253b Mon Sep 17 00:00:00 2001
From: Fred Loader <145092902+loadfred@users.noreply.github.com>
Date: Sat, 4 Nov 2023 23:08:42 +0000
Subject: [PATCH] Resume Hook (Hibernation) (#41)

* hook/resume: hibernation support

* doc/*: added resume to docs

* readme: added resume to readme

* hook/resume: replaced stat

* hook/resume/resume.init: shellcheck fix

---------

Co-authored-by: Fred Loader <16803702-frealo@user.noreply.gitlab.com>
---
 README.md               |  1 +
 doc/tinyramfs.5         |  8 ++++++++
 doc/tinyramfs.5.scd     |  6 ++++++
 hook/resume/resume      |  8 ++++++++
 hook/resume/resume.init | 14 ++++++++++++++
 5 files changed, 37 insertions(+)
 create mode 100644 hook/resume/resume
 create mode 100644 hook/resume/resume.init

diff --git a/README.md b/README.md
index 66f78ed..becd4a6 100644
--- a/README.md
+++ b/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
 
diff --git a/doc/tinyramfs.5 b/doc/tinyramfs.5
index f93ffa1..250b4c7 100644
--- a/doc/tinyramfs.5
+++ b/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
diff --git a/doc/tinyramfs.5.scd b/doc/tinyramfs.5.scd
index ea81ce6..c892218 100644
--- a/doc/tinyramfs.5.scd
+++ b/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
diff --git a/hook/resume/resume b/hook/resume/resume
new file mode 100644
index 0000000..f4137f8
--- /dev/null
+++ b/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
diff --git a/hook/resume/resume.init b/hook/resume/resume.init
new file mode 100644
index 0000000..2c3de5e
--- /dev/null
+++ b/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