From 96dc68a349663d38f0846165750acd0e3c3426eb Mon Sep 17 00:00:00 2001
From: Valentin Brandl <mail@vbrandl.net>
Date: Mon, 14 Nov 2022 00:19:51 +0100
Subject: [PATCH] Set kernel parameters to allow for hibernation

---
 machines/morpheus.nix | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/machines/morpheus.nix b/machines/morpheus.nix
index c6e11f8..0ef0aec 100644
--- a/machines/morpheus.nix
+++ b/machines/morpheus.nix
@@ -2,6 +2,7 @@ inputs:
 let
   system = "x86_64-linux";
   hostname = "morpheus";
+  swapUUID = "93bdadfc-961a-4ea6-aef0-d3cd50847f0b";
 in
 inputs.nixpkgs.lib.nixosSystem {
   inherit system;
@@ -71,6 +72,13 @@ inputs.nixpkgs.lib.nixosSystem {
         kernelModules = [ "kvm-amd" ];
         # use latest kernel
         kernelPackages = pkgs.linuxPackages_latest;
+        kernelParams = [
+          /* enable hibernation with swapfile */
+          /* https://wiki.archlinux.org/title/Power_management/Suspend_and_hibernate#Hibernation_into_swap_file */
+          ("resume=UUID=" + swapUUID)
+/* sudo filefrag -v /swap/swapfile | awk '$1=="0:" {print substr($4, 1, length($4)-2)}' */
+          "resume_offset=269568"
+        ];
         kernel.sysctl = {
           # function keys on keychron keyboard won't work otherwise
           "module.hid_apple.parameters.fnmode" = "2";
@@ -113,7 +121,7 @@ inputs.nixpkgs.lib.nixosSystem {
         };
 
       fileSystems."/swap" =
-        { device = "/dev/disk/by-uuid/93bdadfc-961a-4ea6-aef0-d3cd50847f0b";
+        { device = "/dev/disk/by-uuid/" + swapUUID;
           fsType = "btrfs";
           options = [ "subvol=swap" "noatime" ];
         };