From 40df39634be08d11fbd8df389395f3c49d3080ef Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=B6rg=20Thalheim?= <joerg@thalheim.io>
Date: Mon, 5 Sep 2022 05:32:46 +0000
Subject: [PATCH 1/3] kexec: redue memory usage in test

---
 nix/kexec-installer-test.nix | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/nix/kexec-installer-test.nix b/nix/kexec-installer-test.nix
index 17a0eed..dc613fb 100644
--- a/nix/kexec-installer-test.nix
+++ b/nix/kexec-installer-test.nix
@@ -16,7 +16,7 @@ in makeTest' {
   nodes = {
     node1 = { ... }: {
       virtualisation.vlans = [ ];
-      virtualisation.memorySize = 4 * 1024;
+      virtualisation.memorySize = 2 * 1024 + 512;
       virtualisation.diskSize = 4 * 1024;
       virtualisation.useBootLoader = true;
       virtualisation.useEFIBoot = true;

From b630b3fb37320efd1ee827f55da4cff5b793dedf Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=B6rg=20Thalheim?= <joerg@thalheim.io>
Date: Mon, 5 Sep 2022 05:35:19 +0000
Subject: [PATCH 2/3] kexec: create toplevel kexec directory for unpacking

---
 nix/kexec-installer-test.nix |  6 ++----
 nix/kexec-installer.nix      | 16 ++++++++--------
 2 files changed, 10 insertions(+), 12 deletions(-)

diff --git a/nix/kexec-installer-test.nix b/nix/kexec-installer-test.nix
index dc613fb..c38ab27 100644
--- a/nix/kexec-installer-test.nix
+++ b/nix/kexec-installer-test.nix
@@ -55,10 +55,8 @@ in makeTest' {
     # Kexec node1 to the toplevel of node2 via the kexec-boot script
     node1.succeed('touch /run/foo')
     node1.fail('hello')
-    node1.succeed('mkdir -p /root/kexec')
-    node1.succeed('mkdir -p /root/kexec')
-    node1.succeed('tar -xf ${nodes.node2.config.system.build.kexecTarball}/tarball/nixos-kexec-installer-${pkgs.system}.tar.xz -C /root/kexec')
-    node1.execute('/root/kexec/kexec-boot')
+    node1.succeed('tar -xf ${nodes.node2.config.system.build.kexecTarball}/tarball/nixos-kexec-installer-${pkgs.system}.tar.xz -C /root')
+    node1.execute('/root/kexec/run')
     # wait for machine to kexec
     node1.execute('sleep 9999', check_return=False)
     node1.succeed('! test -e /run/foo')
diff --git a/nix/kexec-installer.nix b/nix/kexec-installer.nix
index 6115a77..643a267 100644
--- a/nix/kexec-installer.nix
+++ b/nix/kexec-installer.nix
@@ -9,7 +9,7 @@
 
   # This is a variant of the upstream kexecScript that also allows embedding
   # a ssh key.
-  system.build.kexecBoot = lib.mkForce (pkgs.writeScript "kexec-boot" ''
+  system.build.kexecRun = lib.mkForce (pkgs.writeScript "kexec-run" ''
     #!/usr/bin/env bash
     set -ex
     shopt -s nullglob
@@ -17,7 +17,7 @@
     INITRD_TMP=$(mktemp -d)
     cd "$INITRD_TMP"
     pwd
-    mkdir initrd initrd/ssh
+    mkdir -p initrd/ssh
     pushd initrd
     if [ -e /root/.ssh/authorized_keys ]; then
       cat /root/.ssh/authorized_keys >> ssh/authorized_keys
@@ -28,7 +28,7 @@
     for p in /etc/ssh/ssh_host_*; do
       cp -a "$p" ssh
     done
-    find -type f | cpio -o -H newc | gzip -9 > ../extra.gz
+    find | cpio -o -H newc | gzip -9 > ../extra.gz
     popd
     cat "''${SCRIPT_DIR}/initrd.gz" extra.gz > final.gz
 
@@ -55,19 +55,19 @@
     fileName = "nixos-kexec-installer-${pkgs.stdenv.hostPlatform.system}";
     contents = [
       {
-        target = "/initrd.gz";
+        target = "/kexec/initrd.gz";
         source = "${config.system.build.netbootRamdisk}/initrd";
       }
       {
-        target = "/bzImage";
+        target = "/kexec/bzImage";
         source = "${config.system.build.kernel}/${config.system.boot.loader.kernelFile}";
       }
       {
-        target = "/kexec-boot";
-        source = config.system.build.kexecBoot;
+        target = "/kexec/run";
+        source = config.system.build.kexecRun;
       }
       {
-        target = "/kexec";
+        target = "/kexec/kexec";
         source = "${pkgs.pkgsStatic.kexec-tools}/bin/kexec";
       }
     ];

From 2913702b16844e07426b7f32a2daebf663e5a6e8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=B6rg=20Thalheim?= <joerg@thalheim.io>
Date: Mon, 5 Sep 2022 05:35:55 +0000
Subject: [PATCH 3/3] kexec: add reboot message

---
 nix/kexec-installer.nix | 1 +
 1 file changed, 1 insertion(+)

diff --git a/nix/kexec-installer.nix b/nix/kexec-installer.nix
index 643a267..c135052 100644
--- a/nix/kexec-installer.nix
+++ b/nix/kexec-installer.nix
@@ -40,6 +40,7 @@
     rm -r "$INITRD_TMP"
 
     # Disconnect our background kexec from the terminal
+    echo "machine will boot into nixos in in 6s..."
     if [[ -e /dev/kmsg ]]; then
       # this makes logging visible in `dmesg`, or the system consol or tools like journald
       exec > /dev/kmsg 2>&1