From d78aa080f5ba5f0920dd3e8a212c8c02cde411a3 Mon Sep 17 00:00:00 2001
From: Graham Christensen <graham@grahamc.com>
Date: Wed, 28 Oct 2020 15:53:10 -0400
Subject: [PATCH 1/2] make-disk-image: support legacy+gpt

---
 nixos/lib/make-disk-image.nix | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/nixos/lib/make-disk-image.nix b/nixos/lib/make-disk-image.nix
index 8aa606a56af8..a4a488a1b3ea 100644
--- a/nixos/lib/make-disk-image.nix
+++ b/nixos/lib/make-disk-image.nix
@@ -28,6 +28,9 @@
   #   partition of reasonable size is created in addition to the root partition.
   # For "legacy", the msdos partition table is used and a single large root
   #   partition is created.
+  # For "legacy+gpt", the GPT partition table is used, a 1MiB no-fs partition for
+  #   use by the bootloader is created, and a single large root partition is
+  #   created.
   # For "hybrid", the GPT partition table is used and a mandatory ESP
   #   partition of reasonable size is created in addition to the root partition.
   #   Also a legacy MBR will be present.
@@ -54,7 +57,7 @@
   format ? "raw"
 }:
 
-assert partitionTableType == "legacy" || partitionTableType == "efi" || partitionTableType == "hybrid" || partitionTableType == "none";
+assert partitionTableType == "legacy" || partitionTableType == "legacy+gpt" || partitionTableType == "efi" || partitionTableType == "hybrid" || partitionTableType == "none";
 # We use -E offset=X below, which is only supported by e2fsprogs
 assert partitionTableType != "none" -> fsType == "ext4";
 
@@ -75,6 +78,7 @@ let format' = format; in let
 
   rootPartition = { # switch-case
     legacy = "1";
+    "legacy+gpt" = "2";
     efi = "2";
     hybrid = "3";
   }.${partitionTableType};
@@ -85,6 +89,16 @@ let format' = format; in let
         mklabel msdos \
         mkpart primary ext4 1MiB -1
     '';
+    "legacy+gpt" = ''
+      parted --script $diskImage -- \
+        mklabel gpt \
+        mkpart no-fs 1MB 2MB \
+        set 1 bios_grub on \
+        align-check optimal 1 \
+        mkpart primary ext4 2MB -1 \
+        align-check optimal 2 \
+        print
+    '';
     efi = ''
       parted --script $diskImage -- \
         mklabel gpt \

From d77ddf2a40641f346d9286e29f78ca9dfc64d533 Mon Sep 17 00:00:00 2001
From: Graham Christensen <graham@grahamc.com>
Date: Wed, 28 Oct 2020 15:54:38 -0400
Subject: [PATCH 2/2] nixos.amazonAmi: use legacy+gpt disk images to support
 partitions >2T

---
 nixos/maintainers/scripts/ec2/amazon-image.nix | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/nixos/maintainers/scripts/ec2/amazon-image.nix b/nixos/maintainers/scripts/ec2/amazon-image.nix
index b09f4ca47a3f..0ecf07669a11 100644
--- a/nixos/maintainers/scripts/ec2/amazon-image.nix
+++ b/nixos/maintainers/scripts/ec2/amazon-image.nix
@@ -57,7 +57,7 @@ in {
     inherit (cfg) contents format name;
     pkgs = import ../../../.. { inherit (pkgs) system; }; # ensure we use the regular qemu-kvm package
     partitionTableType = if config.ec2.efi then "efi"
-                         else if config.ec2.hvm then "legacy"
+                         else if config.ec2.hvm then "legacy+gpt"
                          else "none";
     diskSize = cfg.sizeMB;
     fsType = "ext4";