From 17d2029ba21647344c389c882c1babe9848f7501 Mon Sep 17 00:00:00 2001
From: colin <colin@uninsane.org>
Date: Fri, 24 Jun 2022 00:53:43 -0700
Subject: [PATCH] image: make the gpt headerHole configurable

---
 machines/moby/firmware.nix | 3 +++
 modules/image.nix          | 7 +++++--
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/machines/moby/firmware.nix b/machines/moby/firmware.nix
index 29a30fca..a8a89ead 100644
--- a/machines/moby/firmware.nix
+++ b/machines/moby/firmware.nix
@@ -1,5 +1,8 @@
 { config, pkgs, ... }:
 {
+  # we need space in the GPT header to place tow-boot.
+  # only actually need 1 MB, but better to over-allocate than under-allocate
+  colinsane.image.extraGPTPadding = 16 * 1024 * 1024;
   system.build.img = pkgs.runCommandNoCC "nixos_full-disk-image.img" {} ''
     cp -v ${config.system.build.img-without-firmware}/nixos.img $out
     chmod +w $out
diff --git a/modules/image.nix b/modules/image.nix
index 45134b64..5673221b 100644
--- a/modules/image.nix
+++ b/modules/image.nix
@@ -10,6 +10,10 @@ in
       default = [];
       type = types.listOf types.package;
     };
+    colinsane.image.extraGPTPadding = mkOption {
+      default = 0;
+      type = types.int;
+    };
   };
   config = let
     # return true if super starts with sub
@@ -52,8 +56,7 @@ in
       # leave some space for firmware
       # TODO: we'd prefer to turn this into a protected firmware partition, rather than reserving space in the GPT header itself
       # Tow-Boot manages to do that; not sure how.
-      # TODO: does this method work on all systems (test on lappy)
-      headerHole = imageBuilder.size.MiB 16;
+      headerHole = cfg.extraGPTPadding;
       partitions = [
         (fsBuilderMapBoot."${bootFs.fsType}" {
           # fs properties