Flake update: build sim & toolchain (#16)

Author: khaser

cpu-rtl

@@ -3,52 +3,107 @@
 
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-25.05";
+    nixpkgs-circt.url = "github:NixOS/nixpkgs/nixos-25.05";
     flake-utils.url = "github:numtide/flake-utils";
   };
 
-  outputs = { self, nixpkgs, flake-utils }:
+  outputs = { self, nixpkgs, nixpkgs-circt, flake-utils }:
     flake-utils.lib.eachDefaultSystem ( system:
     let
-      pkgs = import nixpkgs { inherit system; };
-      gccForLibs = pkgs.stdenv.cc.cc;
+      pkgs = import nixpkgs { inherit system; config.allowUnfree = true; };
+      circt = (import nixpkgs-circt { inherit system; }).circt;
+      pkgsRV = pkgs.pkgsCross.riscv64;
+      targetLlvmLibraries = pkgsRV.llvmPackages_21;
     in rec {
 
-      defaultPackage = pkgs.stdenv.mkDerivation {
-        name = "llvm";
+      defaultPackage = packages.toolchain;
 
-        dontUnpack = true;
+      packages.toolchain = with pkgsRV; (wrapCCWith rec {
+        cc = (targetLlvmLibraries.clang-unwrapped.override {
+                src = ./.;
+                libllvm = (targetLlvmLibraries.libllvm.override { src = ./.; });
+              });
+        # libstdcxx is taken from gcc in an ad-hoc way in cc-wrapper.
+        libcxx = null;
+        extraPackages = [ targetLlvmLibraries.compiler-rt ];
+        extraBuildCommands = ''
+          rsrc="$out/resource-root"
+          mkdir "$rsrc"
+          ln -s "${lib.getLib cc}/lib/clang/*/include" "$rsrc"
+          echo "-resource-dir=$rsrc" >> $out/nix-support/cc-cflags
+          ln -s "${targetLlvmLibraries.compiler-rt.out}/lib" "$rsrc/lib"
+          ln -s "${targetLlvmLibraries.compiler-rt.out}/share" "$rsrc/share"
+        '';
+      });
 
-        buildInputs = with pkgs; [
+      packages.sim = pkgs.stdenv.mkDerivation {
+        name = "fck-china-sim";
+        # Floating derivation!!!
+        __impure = true;
+
+        src = pkgs.fetchgit {
+          url = "https://github.com/OpenXiangShan/XiangShan.git";
+          rev = "0fb84f8ddbfc9480d870f72cc903ac6453c888c9";
+          fetchSubmodules = true;
+          leaveDotGit = true;
+          sha256 = "sha256-C+y//RJxI8FwYWCs8dmYLh8ZGVNCTAnRoiOVuY913Jg=";
+          deepClone = false;
+        };
+
+        nativeBuildInputs = with pkgs; [
+          mill
+          time
+          git
+          espresso
+          verilator
           python3
-          ninja
-          cmake
         ];
 
-        cmakeFlags = [
-            "-DUSE_DEPRECATED_GCC_INSTALL_PREFIX=1"
-            "-DGCC_INSTALL_PREFIX=${pkgs.gcc}"
-            "-DC_INCLUDE_DIRS=${pkgs.stdenv.cc.libc.dev}/include"
-            "-GNinja"
-            # Debug for debug builds
-            "-DCMAKE_BUILD_TYPE=Release"
-            # inst will be our installation prefix
-            "-DCMAKE_INSTALL_PREFIX=../inst"
-            "-DLLVM_INSTALL_TOOLCHAIN_ONLY=ON"
-            # change this to enable the projects you need
-            "-DLLVM_ENABLE_PROJECTS=clang"
-            # enable libcxx* to come into play at runtimes
-            "-DLLVM_ENABLE_RUNTIMES=libcxx;libcxxabi"
-            # this makes llvm only to produce code for the current platform, this saves CPU time, change it to what you need
-            "-DLLVM_TARGETS_TO_BUILD=host"
-            "-S ${self}/llvm"
+        buildInputs = with pkgs; [
+          sqlite.dev
+          zlib.dev
+          zstd.dev
         ];
+
+        buildPhase = ''
+          runHook preBuild
+
+          # Copy sources
+          export NOOP_HOME=$out/src
+          echo src = $src
+          echo NOOP_HOME = $NOOP_HOME
+          mkdir -p $NOOP_HOME
+          cp -r $src/* $src/.* $NOOP_HOME
+
+          # Patch shebangs
+          chmod u+wx -R $NOOP_HOME
+          patchShebangs --build $NOOP_HOME/scripts/
+
+          # Build
+          export _JAVA_OPTIONS="-XX:+UseZGC -XX:+ZUncommit -XX:ZUncommitDelay=30"
+          FIRTOOL=${circt}/bin/firtool JVM_XMX=20G make -j8 -C $NOOP_HOME emu
+
+          runHook postBuild
+        '';
+
+        installPhase = ''
+          runHook preInstall
+
+          mkdir -p $out/bin
+          chmod u+x -R $out/src/build/
+          cp $out/src/build/verilator-compile/emu $out/bin
+          rm -rf $out/src
+
+          runHook postInstall
+        '';
       };
 
       devShell = (defaultPackage.overrideAttrs (oldAttrs: {
         name = "llvm-env";
-        buildInputs = oldAttrs.buildInputs ++ (with pkgs; [ verilator ]);
+        buildInputs = oldAttrs.buildInputs;
       }));
 
+
     });
 }