Add flake.nix for Chipyard development

flake.nix

@@ -0,0 +1,75 @@
+{
+  description = "Development shell for Chipyard";
+
+  # Nixpkgs version to use
+  inputs.nixpkgs.url = "nixpkgs/nixos-23.05";
+
+  outputs = { self, nixpkgs }:
+    let
+      # System types to support.
+      # I have only ever tested this on x86_64-linux, so we limit to that.
+      supportedSystems = [ "x86_64-linux" ]; # "x86_64-darwin" "aarch64-linux" "aarch64-darwin" ];
+
+      # Helper function to generate an attrset '{ x86_64-linux = f "x86_64-linux"; ... }'.
+      forAllSystems = nixpkgs.lib.genAttrs supportedSystems;
+
+      # Nixpkgs instantiated for supported system types.
+      nixpkgsFor = forAllSystems (system: import nixpkgs { inherit system; });
+    in
+      {
+        # This flake does not provide any packages
+        packages = {};
+
+        # This flake does not provide any packages, so it cannot have apps
+        # either.
+        # apps is meant to play with the "nix run" command.
+        apps = {};
+
+        # What we really want
+        devShells = forAllSystems (system:
+          let pkgs = nixpkgsFor.${system};
+          in {
+            default = pkgs.mkShell {
+              buildInputs = with pkgs; [
+                svls      # SystemVerilog Language Server
+                verilator # (System)Verilog Simulator/Compiler
+
+                autoconf automake
+                sbt
+                scala
+
+                # ChipYard Dependencies
+                coreutils moreutils binutils
+                bison
+                flex
+                gmp mpfr libmpc zlib
+                vim git jdk17
+                texinfo gengetopt
+                expat libusb ncurses cmake
+                perl perlPackages.ExtUtilsMakeMaker
+                # Deps for poky
+                python3 patch diffstat texinfo subversion chrpath git wget
+                # Deps for qemu
+                gtk3 pkg-config
+                # Deps for firemarshall
+                python3 python3Packages.pip
+                rsync libguestfs texinfo expat ctags
+                # Install dtc
+                dtc
+
+                # keep this line if you use bash
+                bashInteractive
+              ];
+
+              # Ensure locales are present
+              LOCALE_ARCHIVE = "${pkgs.glibcLocales}/lib/locale/locale-archive";
+
+              hardeningDisable = [ "all" ];
+
+              shellHook = ''
+                unset OBJCOPY
+              '';
+            };
+          });
+      };
+}