From 58c287ef6ad4b2a387252acd9890938670322ea5 Mon Sep 17 00:00:00 2001
From: Daniel Barlow <dan@telent.net>
Date: Fri, 7 Oct 2022 00:21:04 +0100
Subject: [PATCH] add config option for kernel commmand line

---
 default.nix      | 3 ++-
 modules/base.nix | 8 ++++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/default.nix b/default.nix
index d92c5eb..e403b60 100644
--- a/default.nix
+++ b/default.nix
@@ -5,6 +5,7 @@ let
   overlay = import ./overlay.nix;
   nixpkgs = import <nixpkgs> ( device.system // {overlays = [overlay]; });
   inherit (nixpkgs.pkgs) callPackage writeText liminix;
+  inherit (nixpkgs.lib) concatStringsSep;
   config = (import ./merge-modules.nix) [
     ./modules/base.nix
     ({ lib, ... } : { config = { inherit (device) kernel; }; })
@@ -24,7 +25,7 @@ let
 
     };
     uimage = kernel.uimage {
-      commandLine = "earlyprintk=serial,ttyS0 console=ttyS0,115200 panic=10 oops=panic init=/bin/init loglevel=8 rootfstype=squashfs";
+      commandLine = concatStringsSep " " config.boot.commandLine;
       inherit (device.boot) loadAddress entryPoint;
       inherit (kernel) vmlinux;
       inherit dtb;
diff --git a/modules/base.nix b/modules/base.nix
index 9607541..ca31a88 100644
--- a/modules/base.nix
+++ b/modules/base.nix
@@ -34,6 +34,9 @@ in {
         default = {};
       };
     };
+    boot.commandLine = mkOption {
+      type = types.listOf types.nonEmptyStr;
+    };
     groups =  mkOption {
       type = types.attrsOf types.anything;
     };
@@ -50,9 +53,14 @@ in {
         IKCONFIG = "y";
         IKCONFIG_PROC = "y";
         PROC_FS = "y";
+        # s6-linux-init mounts this on /dev
+        DEVTMPFS = "y";
       };
       checkedConfig = config;
     };
+    boot.commandLine = [
+      "earlyprintk=serial,ttyS0 console=ttyS0,115200 panic=10 oops=panic init=/bin/init loglevel=8 rootfstype=squashfs"
+    ];
     users.root = {
       uid = 0; gid= 0; gecos = "Root of all evaluation";
       dir = "/";