extract common code for patching kernel source fdorm openwrt

pkgs/default.nix

@@ -38,4 +38,6 @@
   lzma = callPackage ./lzma {};
 
   swconfig = callPackage ./swconfig {};
+
+  openwrt = callPackage ./openwrt {};
 }

pkgs/openwrt/default.nix

@@ -0,0 +1,41 @@
+{
+  fetchFromGitHub
+, writeShellScript
+}:
+let
+  src = fetchFromGitHub {
+    name = "openwrt-source";
+    repo = "openwrt";
+    owner = "openwrt";
+    rev = "a5265497a4f6da158e95d6a450cb2cb6dc085cab";
+    hash = "sha256-YYi4gkpLjbOK7bM2MGQjAyEBuXJ9JNXoz/JEmYf8xE8=";
+  };
+in {
+  inherit src;
+  applyPatches.ath79 = writeShellScript "apply-patches-ath79" ''
+    cp -av ${src}/target/linux/generic/files/* .
+    chmod -R u+w .
+    cp -av ${src}/target/linux/ath79/files/* .
+    chmod -R u+w .
+    patches() {
+      for i in $* ; do patch --batch --forward -p1 < $i ;done
+    }
+    patches ${src}/target/linux/generic/backport-5.15/*.patch
+    patches ${src}/target/linux/generic/pending-5.15/*.patch
+    patches ${src}/target/linux/generic/hack-5.15/*.patch
+    patches ${src}/target/linux/ath79/patches-5.15/*.patch
+  '';
+  applyPatches.ramips = writeShellScript "apply-patches-ramips" ''
+    cp -av ${src}/target/linux/generic/files/* .
+    chmod -R u+w .
+    cp -av ${src}/target/linux/ramips/files/* .
+    chmod -R u+w .
+    patches() {
+      for i in $* ; do patch --batch --forward -p1 < $i ;done
+    }
+    patches ${src}/target/linux/generic/backport-5.15/*.patch
+    patches ${src}/target/linux/generic/pending-5.15/*.patch
+    patches ${src}/target/linux/generic/hack-5.15/*.patch
+    patches ${src}/target/linux/ramips/patches-5.15/*.patch
+  '';
+}