From 4d667685c24c3e99cc70156f3172d5ed5f2ceaa6 Mon Sep 17 00:00:00 2001
From: Linus Heckemann <git@sphalerite.org>
Date: Fri, 26 Apr 2019 00:33:40 +0200
Subject: [PATCH] nixos/kexec: don't clobber existing kexec-loaded kernel

---
 nixos/modules/system/boot/kexec.nix | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/nixos/modules/system/boot/kexec.nix b/nixos/modules/system/boot/kexec.nix
index 61f9c6d0e7e..ecbeea74ab8 100644
--- a/nixos/modules/system/boot/kexec.nix
+++ b/nixos/modules/system/boot/kexec.nix
@@ -13,6 +13,9 @@
         path = [ pkgs.kexectools ];
         script =
           ''
+            # Don't load the current system profile if we already have a kernel loaded
+            [[ 1 = "$(</sys/kernel/kexec_loaded)" ]] && exit
+
             p=$(readlink -f /nix/var/nix/profiles/system)
             if ! [ -d $p ]; then exit 1; fi
             exec kexec --load $p/kernel --initrd=$p/initrd --append="$(cat $p/kernel-params) init=$p/init"