From 72bb3fd7b0359e72723eb662298759adba9995cc Mon Sep 17 00:00:00 2001
From: zowoq <59103226+zowoq@users.noreply.github.com>
Date: Sat, 12 Oct 2024 14:34:11 +1000
Subject: [PATCH] set gcc.arch, extra-platforms, system-features

---
 hosts/build01/default.nix |  2 ++
 hosts/build02/default.nix |  2 ++
 hosts/build03/default.nix |  6 ++++++
 hosts/build04/default.nix |  2 ++
 modules/nixos/builder.nix | 20 ++++++++++++++++++++
 5 files changed, 32 insertions(+)

diff --git a/hosts/build01/default.nix b/hosts/build01/default.nix
index d5f608cf0..b2e411fee 100644
--- a/hosts/build01/default.nix
+++ b/hosts/build01/default.nix
@@ -7,6 +7,8 @@
     inputs.self.nixosModules.community-builder
   ];
 
+  nixpkgs.hostPlatform.gcc.arch = "znver2";
+
   # Emulate riscv64 until we have proper builders
   boot.binfmt.emulatedSystems = [ "riscv64-linux" ];
 
diff --git a/hosts/build02/default.nix b/hosts/build02/default.nix
index 2bbc8d974..57ce99140 100644
--- a/hosts/build02/default.nix
+++ b/hosts/build02/default.nix
@@ -10,6 +10,8 @@
     inputs.self.nixosModules.disko-zfs
   ];
 
+  nixpkgs.hostPlatform.gcc.arch = "znver2";
+
   # set in srvos, remove when reinstalling
   networking.hostId = "deadbeef";
 
diff --git a/hosts/build03/default.nix b/hosts/build03/default.nix
index 17e984bc1..2c799ca74 100644
--- a/hosts/build03/default.nix
+++ b/hosts/build03/default.nix
@@ -16,6 +16,12 @@
     ./postgresql.nix
   ];
 
+  nixpkgs.hostPlatform.gcc.arch = "znver4";
+
+  nix.settings.extra-platforms = [
+    "x86_64-v4-linux"
+  ];
+
   systemd.network.networks."10-uplink".networkConfig.Address = "2a01:4f8:2190:2698::2";
 
   system.stateVersion = "23.11";
diff --git a/hosts/build04/default.nix b/hosts/build04/default.nix
index c270f6fb1..c777e1344 100644
--- a/hosts/build04/default.nix
+++ b/hosts/build04/default.nix
@@ -8,6 +8,8 @@
     inputs.self.nixosModules.remote-builder
   ];
 
+  nixpkgs.hostPlatform.gcc.arch = "armv8-a";
+
   # error: failed to start SSH connection
   # https://github.com/nix-community/infra/issues/1416
   services.openssh.settings.MaxStartups = 100;
diff --git a/modules/nixos/builder.nix b/modules/nixos/builder.nix
index d6e1061df..9a0173610 100644
--- a/modules/nixos/builder.nix
+++ b/modules/nixos/builder.nix
@@ -1,12 +1,32 @@
 {
   config,
   inputs,
+  lib,
   pkgs,
   ...
 }:
 {
   nix.gc.automatic = false;
 
+  nixpkgs.hostPlatform = {
+    inherit (pkgs.hostPlatform) system;
+  };
+
+  nix.settings.extra-platforms = lib.mkIf (config.nixpkgs.hostPlatform.system == "x86_64-linux") [
+    "i686-linux"
+    "x86_64-v1-linux"
+    "x86_64-v2-linux"
+    "x86_64-v3-linux"
+  ];
+
+  nix.settings.system-features = [
+    "benchmark"
+    "big-parallel"
+    "gccarch-${config.nixpkgs.hostPlatform.gcc.arch}"
+    "kvm"
+    "nixos-test"
+  ];
+
   systemd.services.free-space = {
     serviceConfig.Type = "oneshot";
     startAt = "hourly";