per-device dts

default.nix

@@ -37,7 +37,7 @@ let
       inherit (config.kernel) config;
     };
     dtb =  (callPackage ./kernel/dtb.nix {}) {
-      dts = "${openwrt}/target/linux/ath79/dts/qca9531_glinet_gl-ar750.dts";
+      dts = config.kernel.dts { inherit openwrt; };
       includes = [
         "${openwrt}/target/linux/ath79/dts"
         "${kernel.headers}/include"

devices/gl-ar750/default.nix

@@ -62,6 +62,7 @@
       };
     };
   kernel = rec {
+    dts = { openwrt,... }:"${openwrt}/target/linux/ath79/dts/qca9531_glinet_gl-ar750.dts";
     config = {
       MIPS_ELF_APPENDED_DTB = "y";
       OF = "y";

modules/base.nix

@@ -24,6 +24,7 @@ in {
     };
     filesystem = mkOption { type = types.anything; };
     kernel = {
+      dts = mkOption { type = types.functionTo types.string; };
       config = mkOption {
         # mostly the values are y n or m, but sometimes
         # other strings are also used