starfive visionfive2: replace 8GB memory patch with overlay

starfive/visionfive/v2/README.md

@@ -31,10 +31,6 @@ Create and configure the `flake.nix` file:
               # networking.interfaces.end0.useDHCP = true;
               # networking.interfaces.end1.useDHCP = true;
 
-              # If you have the 2A variant uncomment the following line
-              # hardware.deviceTree.name =
-              #   lib.mkDefault "starfive/jh7110-starfive-visionfive-2-v1.2a.dtb";
-
               # Additional configuration goes here
 
               sdImage.compressImage = false;
@@ -57,3 +53,33 @@ Build the sd image.
 ``` sh
 nix build .#
 ```
+
+## Additional configuration
+Additional configuration may be needed depending on your specific hardware configuration.
+### Board rev 1.2A
+If you have the 1.2A board revision add the following to your config:
+``` nix
+hardware.deviceTree.name =
+  lib.mkDefault "starfive/jh7110-starfive-visionfive-2-v1.2a.dtb";
+```
+
+### 8GB memory
+If your board has 8GB of RAM add the following to your config:
+
+#### Board rev 1.3B
+``` nix
+hardware.deviceTree.overlays = [{
+  name = "8GB-patch";
+  dtsFile =
+    "${nixos-hardware}/starfive/visionfive/v2/visionfive-2-v1.3b-8GB.dts";
+}];
+```
+
+#### Board rev 1.2A
+``` nix
+hardware.deviceTree.overlays = [{
+  name = "8GB-patch";
+  dtsFile =
+    "${nixos-hardware}/starfive/visionfive/v2/visionfive-2-v1.2a-8GB.dts";
+}];
+```

starfive/visionfive/v2/fix-memory-size.patch

@@ -1,13 +0,0 @@
-diff --git a/arch/riscv/boot/dts/starfive/jh7110-starfive-visionfive-2.dtsi b/arch/riscv/boot/dts/starfive/jh7110-starfive-visionfive-2.dtsi
-index 752bb0b6fd00..93670da6cabd 100644
---- a/arch/riscv/boot/dts/starfive/jh7110-starfive-visionfive-2.dtsi
-+++ b/arch/riscv/boot/dts/starfive/jh7110-starfive-visionfive-2.dtsi
-@@ -30,7 +30,7 @@ cpus {
- 
- 	memory@40000000 {
- 		device_type = "memory";
--		reg = <0x0 0x40000000 0x1 0x0>;
-+		reg = <0x0 0x40000000 0x2 0x0>;
- 	};
- 
- 	thermal-zones {

starfive/visionfive/v2/linux-6.3.nix

@@ -15,7 +15,6 @@ let
 
       inherit modDirVersion;
       kernelPatches = [
-        { patch = ./fix-memory-size.patch; }
         {
           patch = fetchpatch {
             url =

starfive/visionfive/v2/visionfive-2-v1.2a-8GB.dts

@@ -0,0 +1,11 @@
+/dts-v1/;
+/plugin/;
+/ {
+	compatible = "starfive,visionfive-2-v1.2a", "starfive,jh7110";
+	fragment@0 {
+		target-path = "/memory@40000000";
+		__overlay__ {
+			reg = <0x0 0x40000000 0x2 0x0>;
+		};
+	};
+};

starfive/visionfive/v2/visionfive-2-v1.3b-8GB.dts

@@ -0,0 +1,11 @@
+/dts-v1/;
+/plugin/;
+/ {
+	compatible = "starfive,visionfive-2-v1.3b", "starfive,jh7110";
+	fragment@0 {
+		target-path = "/memory@40000000";
+		__overlay__ {
+			reg = <0x0 0x40000000 0x2 0x0>;
+		};
+	};
+};