refactor: move to dpi module for memory access

npc/.clang-format

@@ -0,0 +1,2 @@
+---
+BasedOnStyle: LLVM

npc/.gitignore

@@ -15,3 +15,6 @@ hs_err_pid*
 .vscode/
 .direnv/
 compile_commands.json
+
+/.pre-commit-config.yaml
+

npc/CMakeLists.txt

@@ -30,16 +30,17 @@ if(BUILD_SIM_NVBOARD_TARGET)
   find_package(SDL2 REQUIRED)
   find_package(SDL2_image REQUIRED)
 endif()
+find_package(CLI11 CONFIG REQUIRED)
 
 find_library(NVBOARD_LIBRARY NAMES nvboard)
 find_path(NVBOARD_INCLUDE_DIR NAMES nvboard.h)
 
-# FIXME: all scala source file are tracked here, cause all files to rebuild 
-# after a source update. 
+# FIXME: all scala source file are tracked here, cause all files to rebuild
+# after a source update.
 set(SCALA_CORE "${CMAKE_CURRENT_SOURCE_DIR}/core")
 set(CHISEL_MODULE_CLASS "${CMAKE_PROJECT_NAME}.${TOPMODULE}")
 
-# Verilog files are generted in CHISEL_OUTPUT_TMP_DIR and copy to 
+# Verilog files are generted in CHISEL_OUTPUT_TMP_DIR and copy to
 # CHISEL_OUTPUT_DIR if content changes
 set(CHISEL_OUTPUT_DIR ${CMAKE_CURRENT_BINARY_DIR}/${TOPMODULE}/vsrc/)
 set(CHISEL_OUTPUT_TMP_DIR ${CMAKE_CURRENT_BINARY_DIR}/${TOPMODULE}/vsrc_tmp/)
@@ -52,8 +53,8 @@ set(CHISEL_EMIT_ARGS "--target-dir ${CHISEL_OUTPUT_TMP_DIR}")
 #    as we don't know if the result files will be different from cmake
 # NOTE: Must reconfigure if we add new files in SCALA_CORE directory
 file(GLOB_RECURSE SCALA_CORE_SOURCES "${SCALA_CORE}/src/main/scala/*.scala")
-file(GLOB_RECURSE SCALA_CORE_RESOURCES "${SCALA_CORE}/src/resource/*")
-set(CHISEL_DEPENDENCY ${SCALA_CORE_SOURCES} ${SCALA_CORE_RESOURCE} ${SCALA_CORE}/build.sbt)
+file(GLOB_RECURSE SCALA_CORE_RESOURCES "${SCALA_CORE}/src/main/resource/*")
+set(CHISEL_DEPENDENCY ${SCALA_CORE_SOURCES} ${SCALA_CORE_RESOURCES} ${SCALA_CORE}/build.sbt)
 
 if(BUILD_USE_BLOOP)
   set(CHISEL_TARGET bloop_${TOPMODULE})
@@ -105,7 +106,7 @@ if(NOT EXISTS ${CHISEL_OUTPUT_TOPMODULE})
     WORKING_DIRECTORY ${SCALA_CORE}
   )
   execute_process(
-    COMMAND ${CMAKE_COMMAND} -E copy_directory_if_different ${CHISEL_OUTPUT_TMP_DIR} ${CHISEL_OUTPUT_DIR}
+    COMMAND ${CMAKE_COMMAND} -E copy_directory ${CHISEL_OUTPUT_TMP_DIR} ${CHISEL_OUTPUT_DIR}
   )
 endif()
 
@@ -114,7 +115,7 @@ if(BUILD_SIM_NVBOARD_TARGET)
   add_custom_command(
     OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/${TOPMODULE}/auto_bind.cpp
     COMMAND auto_pin_bind ${CMAKE_SOURCE_DIR}/constr/${TOPMODULE}.nxdc ${CMAKE_CURRENT_BINARY_DIR}/${TOPMODULE}/auto_bind.cpp
-    DEPENDS ${CMAKE_SOURCE_DIR}/constr/${TOPMODULE}.nxdc 
+    DEPENDS ${CMAKE_SOURCE_DIR}/constr/${TOPMODULE}.nxdc
   )
 
   file(GLOB_RECURSE SOURCES csrc_nvboard/${TOPMODULE}/*.cpp)
@@ -144,7 +145,6 @@ verilate(V${TOPMODULE} TRACE COVERAGE THREADS
   INCLUDE_DIRS ${CMAKE_CURRENT_BINARY_DIR}/${TOPMODULE}/vsrc
   VERILATOR_ARGS
     "--vpi"   # Enable VPI
-    
 )
 
 

npc/core/src/main/resources/RamDpi.v

@@ -0,0 +1,24 @@
+import "DPI-C" function int pmem_read(input int addr);
+import "DPI-C" function void pmem_write(input int waddr, input int wdata, input byte wmask);
+
+module RamDpi (
+  input writeEnable,
+  input valid,
+  input [31:0] writeAddr,
+  input [31:0] writeData,
+  input [3:0] writeMask,
+  input reg [31:0] readAddr,
+  output reg [31:0] readData
+);
+  always @(*) begin
+    if (valid) begin // 有读写请求时
+      readData = pmem_read(readAddr);
+      if (writeEnable) begin // 有写请求时
+        pmem_write(writeAddr, writeData, { 4'h0, writeMask });
+      end
+    end
+    else begin
+      readData = 0;
+    end
+  end
+endmodule

npc/core/src/main/scala/FlowMain.scala

@@ -74,27 +74,18 @@ class Control(width: Int) extends Module {
     })
 }
 
-import flow.components.{RegisterFile, ProgramCounter, ALU}
+import flow.components.{RegisterFile, ProgramCounter, ALU, RamDpi}
 import chisel3.util.experimental.loadMemoryFromFileInline
 class Flow extends Module {
   val dataType = UInt(32.W)
-
-  val ram = SRAM(
-    size = 1024,
-    tpe = dataType,
-    numReadPorts = 2,
-    numWritePorts = 1,
-    numReadwritePorts = 0,
-    memoryFile = HexMemoryFile("./resource/addi.txt")
-  )
+  val ram = Module(new RamDpi)
   val control = Module(new Control(32))
   val reg = Module(new RegisterFile(dataType, 32, 2))
   val pc = Module(new ProgramCounter(dataType))
   val alu = Module(new ALU(dataType))
 
-  ram.readPorts(0).enable := true.B
-  ram.readPorts(0).address := pc.out - 0x80000000L.U
-  val inst = ram.readPorts(0).data
+  ram.io.readAddr := pc.out
+  val inst = ram.io.readData
 
   Trace.traceName(reg.control.writeEnable)
   dontTouch(reg.control.writeEnable)
@@ -111,18 +102,20 @@ class Flow extends Module {
 
   import control.reg.WriteSelect._
   reg.in.writeData(rAluOut.litValue.toInt) := alu.out.result
+
   // TODO: Read address in load command goes here
-  ram.readPorts(1).enable := false.B
-  ram.readPorts(1).address := 0.U
-  reg.in.writeData(rMemOut.litValue.toInt) := ram.readPorts(1).data
+  reg.in.writeData(rMemOut.litValue.toInt) := DontCare
+
   reg.in.writeAddr := inst(11, 7)
   reg.in.rs(0) := inst(19, 15)
   reg.in.rs(1) := inst(24, 20)
 
   // TODO: Memory write goes here
-  ram.writePorts(0).address := 1.U
-  ram.writePorts(0).data := 1.U
-  ram.writePorts(0).enable := false.B
+  ram.io.writeAddr := DontCare
+  ram.io.writeData := DontCare
+  ram.io.writeMask := DontCare
+  ram.io.writeEnable := false.B
+  ram.io.valid := true.B
 
   import control.alu.SrcSelect._
   alu.in.a(aSrcRs1.litValue.toInt) := reg.out.src(0)

npc/core/src/main/scala/Mem.scala

@@ -1 +1,24 @@
-package flow.components
+package flow.components
+
+import chisel3._
+import chisel3.util.HasBlackBoxPath
+import chisel3.util.HasBlackBoxResource
+import chisel3.util.log2Ceil
+import chisel3.experimental.noPrefix
+import scala.collection.SeqMap
+import javax.swing.plaf.synth.SynthRadioButtonMenuItemUI
+
+class RamInterface[T <: Data](tpe: T, addrWidth: Int) extends Bundle {
+  val valid = Input(Bool())
+  val writeEnable = Input(Bool())
+  val writeAddr = Input(UInt(addrWidth.W))
+  val writeData = Input(tpe)
+  val writeMask = Input(UInt((addrWidth / 8).W))
+  val readAddr = Input(UInt(addrWidth.W))
+  val readData = Output(tpe)
+}
+
+class RamDpi extends BlackBox with HasBlackBoxResource {
+  val io = IO(new RamInterface(UInt(32.W), 32))
+  addResource("/RamDpi.v")
+}

npc/core/src/main/scala/RegisterFile.scala

@@ -12,7 +12,7 @@ class RegControl extends Bundle {
     val rAluOut, rMemOut = Value
   }
 
-  val writeEnable = Input(Bool()) 
+  val writeEnable = Input(Bool())
   val writeSelect = Input(WriteSelect())
 
   type CtrlTypes = Bool :: WriteSelect.Type :: HNil
@@ -25,7 +25,7 @@ class RegControl extends Bundle {
 class RegisterFile[T <: Data](tpe: T, regCount: Int, numReadPorts: Int) extends Module {
   require(numReadPorts >= 0)
   val control = IO(new RegControl)
-  val dataAddrWidth = log2Ceil(tpe.getWidth).W
+  val dataAddrWidth = log2Ceil(regCount).W
   val in = IO(new Bundle {
     val writeAddr = Input(UInt(dataAddrWidth))
     val writeData = Input(Vec(control.WriteSelect.all.length, tpe))

npc/csrc/Flow/components.hpp

@@ -0,0 +1,101 @@
+
+#ifndef _NPC_COMPONENTS_H_
+#define _NPC_COMPONENTS_H_
+#include <array>
+#include <filesystem>
+#include <fstream>
+#include <verilated_vpi.h>
+
+template <typename T, std::size_t nr> class _RegistersBase {
+  std::array<T, nr> regs;
+  virtual T fetch_reg(std::size_t id);
+
+public:
+  void update() {
+    for (int i = 0; i < regs.size(); i++) {
+      regs[i] = fetch_reg(i);
+    }
+  }
+  void print_regs() {
+    for (int i = 0; i < regs.size(); i++) {
+      printf("%d: %d\t", i, regs[i]);
+      if (i % 8 == 7)
+        putchar('\n');
+    }
+    putchar('\n');
+  }
+};
+
+template <typename T, std::size_t nr>
+class _RegistersVPI : public _RegistersBase<T, nr> {
+  std::array<vpiHandle, nr> reg_handles;
+  T fetch_reg(std::size_t id) {
+    s_vpi_value v;
+    v.format = vpiIntVal;
+    vpi_get_value(reg_handles[id], &v);
+    return v.value.integer;
+  }
+
+public:
+  _RegistersVPI<T, nr>(const std::string regs_prefix) {
+    for (int i = 0; i < nr; i++) {
+      std::string regname = regs_prefix + std::to_string(i);
+      vpiHandle vh = vpi_handle_by_name((PLI_BYTE8 *)regname.c_str(), NULL);
+      reg_handles[i] = vh;
+    }
+  }
+};
+
+template <typename T, std::size_t n> class Memory {
+  std::array<T, n> mem;
+  std::size_t addr_to_index(std::size_t addr) {
+    if (addr < 0x80000000) {
+      return 0;
+    }
+    // Linear mapping
+    return (addr >> 2) - 0x20000000;
+  }
+  uint32_t expand_bits(uint8_t bits) {
+    uint32_t x = bits;
+    x = (x | (x << 7) | (x << 14) | (x << 21)) & 0x01010101;
+    x = x * 0xFF;
+    // printf("expand: %hhx->%x\n", bits, x);
+    return x;
+  }
+
+public:
+  Memory(std::filesystem::path filepath, bool is_binary = true) {
+    assert(std::filesystem::exists(filepath));
+    if (is_binary) {
+      std::ifstream file(filepath, std::ios::binary);
+      char *pmem = reinterpret_cast<char *>(mem.data());
+      file.read(pmem, mem.size() / sizeof(mem[0]));
+    } else {
+      std::string line;
+      std::ifstream file(filepath);
+      int i = 0;
+      while (std::getline(file, line)) {
+        mem[i++] = std::stoul(line, 0, 16);
+      }
+    }
+  }
+  const T &operator[](std::size_t addr) { return this->read(addr); }
+  /**
+   * Always reads and returns 4 bytes from the address raddr & ~0x3u.
+   */
+  T read(int raddr) {
+    printf("raddr: 0x%x\n", raddr);
+    return mem[addr_to_index((uint32_t)raddr)];
+  }
+  /**
+   * Always writes to the 4 bytes at the address `waddr` & ~0x3u.
+   * Each bit in `wmask` represents a mask for one byte in wdata.
+   * For example, wmask = 0x3 means only the lowest 2 bytes are written,
+   * and the other bytes in memory remain unchanged.
+   */
+  void write(int waddr, T wdata, char wmask) {
+    printf("waddr: 0x%x\n", waddr);
+    mem[addr_to_index((uint32_t)waddr)] = expand_bits(wmask) & wdata;
+  }
+};
+#endif

npc/csrc/Flow/config.cpp

@@ -0,0 +1,27 @@
+#include "config.hpp"
+
+void Config::cli_parse(int argc, char **argv) {
+  CLI::App app;
+  app.add_option("-m,--memory", memory_file, "Content of memory")
+      ->required()
+      ->check(CLI::ExistingFile);
+  app.add_flag("!--no-bin", memory_file_binary,
+               "Memory file is in text format");
+  app.add_flag("--trace", do_trace, "Enable tracing");
+  app.add_option("--wav", wavefile, "output .vcd file path")
+      ->check([this](const std::string &) {
+        if (!this->do_trace)
+          throw CLI::ValidationError(
+              "dependency", "You must turn on trace before specify wave file");
+        return std::string();
+      });
+  app.add_option("-t", max_sim_time, "Max simulation timestep");
+
+  try {
+    app.parse(argc, argv);
+  } catch (const CLI::ParseError &e) {
+    exit((app).exit(e));
+  }
+}
+
+Config config;

npc/csrc/Flow/config.hpp

@@ -0,0 +1,19 @@
+#ifndef _NPC_CONFIG_H_
+#define _NPC_CONFIG_H_
+#include <CLI/App.hpp>
+#include <CLI/CLI.hpp>
+#include <CLI/Validators.hpp>
+#include <filesystem>
+
+struct Config {
+  std::filesystem::path wavefile;
+  std::filesystem::path memory_file;
+  uint64_t max_sim_time = 1000;
+  bool memory_file_binary = {true};
+  bool do_trace{false};
+  void cli_parse(int argc, char **argv);
+};
+
+extern Config config;
+
+#endif

npc/csrc/Flow/main.cpp

@@ -1,150 +1,39 @@
-#include <array>
-#include <cstddef>
-#include <cstdint>
-#include <filesystem>
-#include <sys/types.h>
-#include <vpi_user.h>
+#include "components.hpp"
+#include "config.hpp"
+#include "vl_wrapper.hpp"
 #include <VFlow.h>
-#include <cstdlib>
-#include <memory>
-#include <verilated.h>
-#include <verilated_vcd_c.h>
-#include <verilated_vpi.h>
-#include <string>
-#define MAX_SIM_TIME 100
-#define VERILATOR_TRACE
 
-template <class T>
-class Tracer {
-#ifdef VERILATOR_TRACE
-  std::shared_ptr<T> top;
-  std::unique_ptr<VerilatedVcdC> m_trace;
-  uint64_t cycle = 0;
-#endif
-  public:
-    Tracer(T *top, std::filesystem::path wavefile) {
-#ifdef VERILATOR_TRACE
-      top = top;
-      Verilated::traceEverOn(true);
-      m_trace = std::make_unique<VerilatedVcdC>();
-      top->trace(m_trace.get(), 5);
-      m_trace->open(wavefile.c_str());
-#endif
-    }
-    ~Tracer() {
-#ifdef VERILATOR_TRACE
-      m_trace->close();
-#endif
-    }
-    
-    /**
-     * Dump signals to waveform file. Must be called once after every top->eval() call.
-     */
-    void update() {
-#ifdef VERILATOR_TRACE
-      m_trace->dump(cycle++);
-#endif
-    }
-};
-template <typename T, std::size_t nr>
-class _RegistersBase {
-  std::array<T, nr> regs;
-  virtual T fetch_reg(size_t id);
-  public:
-    void update() {
-      for(int i = 0; i < regs.size(); i++) {
-        regs[i] = fetch_reg(i);
-      }
-    }
-    void print_regs() {
-      for(int i = 0; i < regs.size(); i++) {
-        printf("%d: %d\t", i, regs[i]);
-        if(i % 8 == 7) putchar('\n');
-      }
-      putchar('\n');
-    }
-};
+using VlModule = VlModuleInterfaceCommon<VFlow>;
+using Registers = _RegistersVPI<uint32_t, 32>;
 
-template <typename T, std::size_t nr>
-class _RegistersVPI : public _RegistersBase<T, nr> {
-  std::array<vpiHandle, nr> reg_handles;
-  T fetch_reg(size_t id) {
-    s_vpi_value v;
-    v.format = vpiIntVal;
-    vpi_get_value(reg_handles[id], &v);
-    return v.value.integer;
-  }
-  public:
-    _RegistersVPI<T, nr>(const std::string regs_prefix) {
-      for(int i = 0; i < nr; i++) {
-        std::string regname = regs_prefix + std::to_string(i);
-        vpiHandle vh = vpi_handle_by_name((PLI_BYTE8 *)regname.c_str(), NULL);
-        reg_handles[i] = vh;
-      }
-    }
-};
+extern "C" {
+void *pmem_get() {
+  static auto pmem = new Memory<int, 128 * 1024>(config.memory_file,
+                                                 config.memory_file_binary);
+  return pmem;
+}
 
-typedef _RegistersVPI<uint32_t, 32> Registers;
+int pmem_read(int raddr) {
+  void *pmem = pmem_get();
+  auto mem = static_cast<Memory<int, 128 * 1024> *>(pmem);
+  return mem->read(raddr);
+}
 
-template <typename T, std::size_t n>
-class Memory {
-  std::array<T, n> mem;
-  size_t addr_to_index(size_t addr) {
-    // Linear mapping
-    return addr - 0x80000000;
-  }
-  public:
-    const T& operator[](size_t addr) {
-      return mem[addr_to_index(index)];
-    }
-};
-
-template <typename T>
-class VlModuleInterfaceCommon : public T {
-  uint64_t sim_time = 0;
-  uint64_t posedge_cnt = 0;
-  std::unique_ptr<Tracer<T>> tracer;
-  public:
-    VlModuleInterfaceCommon<T>(bool do_trace, std::filesystem::path wavefile = "waveform.vcd") {
-      if(do_trace) tracer = std::make_unique<Tracer<T>>(this, wavefile);
-    } 
-    void eval() {
-      if(this->is_posedge()) {
-        posedge_cnt++;
-      }
-      T::clock = !T::clock;
-      sim_time++;
-      T::eval();
-      if(tracer) tracer->update();
-    }
-    void eval(int n) {
-      for(int i = 0; i < n; i++) {
-        this->eval();
-      }
-    }
-    void reset_eval(int n) {
-      this->reset = 1;
-      this->eval(n);
-      this->reset = 0;
-    }
-    bool is_posedge() {
-      // Will be posedge when eval is called
-      return T::clock == 0;
-    }
-};
-
-typedef VlModuleInterfaceCommon<VFlow> VlModule;
+void pmem_write(int waddr, int wdata, char wmask) {
+  void *pmem = pmem_get();
+  auto mem = static_cast<Memory<int, 128 * 1024> *>(pmem);
+  return mem->write((std::size_t)waddr, wdata, wmask);
+}
+}
 
 int main(int argc, char **argv, char **env) {
-  Verilated::commandArgs(argc, argv);
-
-  auto top = std::make_shared<VlModule>(false, "waveform.vcd");
-
+  config.cli_parse(argc, argv);
+  auto top = std::make_shared<VlModule>(config.do_trace, config.wavefile);
   Registers regs("TOP.Flow.reg_0.regFile_");
 
   top->reset_eval(10);
-  for (int i = 0; i < MAX_SIM_TIME; i++) {
-    if(top->is_posedge()) {
+  for (int i = 0; i < config.max_sim_time; i++) {
+    if (top->is_posedge()) {
       // Posedge
       regs.update();
       regs.print_regs();

npc/csrc/Flow/vl_wrapper.hpp

@@ -0,0 +1,65 @@
+#ifndef _NPC_TRACER_H_
+#define _NPC_TRACER_H_
+#include <filesystem>
+#include <verilated_vcd_c.h>
+
+template <class T> class Tracer {
+  std::shared_ptr<T> top;
+  std::unique_ptr<VerilatedVcdC> m_trace;
+  uint64_t cycle = 0;
+
+public:
+  Tracer(T *top, std::filesystem::path wavefile) {
+    top = top;
+    Verilated::traceEverOn(true);
+    m_trace = std::make_unique<VerilatedVcdC>();
+    top->trace(m_trace.get(), 5);
+    m_trace->open(wavefile.c_str());
+  }
+  ~Tracer() { m_trace->close(); }
+
+  /**
+   * Dump signals to waveform file. Must be called once after every top->eval()
+   * call.
+   */
+  void update() { m_trace->dump(cycle++); }
+};
+
+template <typename T> class VlModuleInterfaceCommon : public T {
+  uint64_t sim_time = 0;
+  uint64_t posedge_cnt = 0;
+  std::unique_ptr<Tracer<T>> tracer;
+
+public:
+  VlModuleInterfaceCommon<T>(bool do_trace,
+                             std::filesystem::path wavefile = "waveform.vcd") {
+    if (do_trace)
+      tracer = std::make_unique<Tracer<T>>(this, wavefile);
+  }
+  void eval() {
+    if (this->is_posedge()) {
+      posedge_cnt++;
+    }
+    T::clock = !T::clock;
+    sim_time++;
+    T::eval();
+    if (tracer)
+      tracer->update();
+  }
+  void eval(int n) {
+    for (int i = 0; i < n; i++) {
+      this->eval();
+    }
+  }
+  void reset_eval(int n) {
+    this->reset = 1;
+    this->eval(n);
+    this->reset = 0;
+  }
+  bool is_posedge() {
+    // Will be posedge when eval is called
+    return T::clock == 0;
+  }
+};
+
+#endif

npc/flake.lock

@@ -1,5 +1,21 @@
 {
   "nodes": {
+    "flake-compat": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1696426674,
+        "narHash": "sha256-kvjfFW7WAETZlt09AgDn1MrtKzP7t90Vf7vypd3OL1U=",
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "rev": "0f9255e01c2351cc7d116c072cb317785dd33b33",
+        "type": "github"
+      },
+      "original": {
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "type": "github"
+      }
+    },
     "flake-utils": {
       "inputs": {
         "systems": "systems"
@@ -18,6 +34,45 @@
         "type": "github"
       }
     },
+    "flake-utils_2": {
+      "inputs": {
+        "systems": "systems_2"
+      },
+      "locked": {
+        "lastModified": 1710146030,
+        "narHash": "sha256-SZ5L6eA7HJ/nmkzGG7/ISclqe6oZdOZTNoesiInkXPQ=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "b1d9ab70662946ef0850d488da1c9019f3a9752a",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "gitignore": {
+      "inputs": {
+        "nixpkgs": [
+          "pre-commit-hooks",
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1709087332,
+        "narHash": "sha256-HG2cCnktfHsKV0s4XW83gU3F57gaTljL9KNSuG6bnQs=",
+        "owner": "hercules-ci",
+        "repo": "gitignore.nix",
+        "rev": "637db329424fd7e46cf4185293b9cc8c88c95394",
+        "type": "github"
+      },
+      "original": {
+        "owner": "hercules-ci",
+        "repo": "gitignore.nix",
+        "type": "github"
+      }
+    },
     "nixpkgs": {
       "locked": {
         "lastModified": 1709961763,
@@ -50,6 +105,22 @@
         "type": "github"
       }
     },
+    "nixpkgs-stable": {
+      "locked": {
+        "lastModified": 1710695816,
+        "narHash": "sha256-3Eh7fhEID17pv9ZxrPwCLfqXnYP006RKzSs0JptsN84=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "614b4613980a522ba49f0d194531beddbb7220d3",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-23.11",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
     "nur-xin": {
       "inputs": {
         "nixpkgs": [
@@ -70,12 +141,37 @@
         "url": "https://git.xinyang.life/xin/nur.git"
       }
     },
+    "pre-commit-hooks": {
+      "inputs": {
+        "flake-compat": "flake-compat",
+        "flake-utils": "flake-utils_2",
+        "gitignore": "gitignore",
+        "nixpkgs": [
+          "nixpkgs"
+        ],
+        "nixpkgs-stable": "nixpkgs-stable"
+      },
+      "locked": {
+        "lastModified": 1712055707,
+        "narHash": "sha256-4XLvuSIDZJGS17xEwSrNuJLL7UjDYKGJSbK1WWX2AK8=",
+        "owner": "cachix",
+        "repo": "pre-commit-hooks.nix",
+        "rev": "e35aed5fda3cc79f88ed7f1795021e559582093a",
+        "type": "github"
+      },
+      "original": {
+        "owner": "cachix",
+        "repo": "pre-commit-hooks.nix",
+        "type": "github"
+      }
+    },
     "root": {
       "inputs": {
         "flake-utils": "flake-utils",
         "nixpkgs": "nixpkgs",
         "nixpkgs-circt162": "nixpkgs-circt162",
-        "nur-xin": "nur-xin"
+        "nur-xin": "nur-xin",
+        "pre-commit-hooks": "pre-commit-hooks"
       }
     },
     "systems": {
@@ -92,6 +188,21 @@
         "repo": "default",
         "type": "github"
       }
+    },
+    "systems_2": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
     }
   },
   "root": "root",

npc/flake.nix

@@ -3,6 +3,10 @@
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
     nixpkgs-circt162.url = "github:NixOS/nixpkgs/7995cae3ad60e3d6931283d650d7f43d31aaa5c7";
     flake-utils.url = "github:numtide/flake-utils";
+    pre-commit-hooks = {
+      url = "github:cachix/pre-commit-hooks.nix";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
     nur-xin = {
       url = "git+https://git.xinyang.life/xin/nur.git";
       inputs.nixpkgs.follows = "nixpkgs";
@@ -16,7 +20,21 @@
           { nur.xin = nur-xin.legacyPackages.${system}; };
       in
       {
+        checks = {
+          pre-commit-check = pre-commit-hooks.lib.${system}.run {
+            src = ./.;
+            hooks = {
+              trim-trailing-whitespace.enable = true;
+              clang-format = {
+                enable = true;
+                types_or = pkgs.lib.mkForce [ "c" "c++" ];
+              };
+            };
+          };
+        };
         devShells.default = with pkgs; mkShell {
+          inherit (self.checks.${system}.pre-commit-check) shellHook;
+          buildInputs = self.checks.${system}.pre-commit-check.enabledPackages;
           CHISEL_FIRTOOL_PATH = "${nixpkgs-circt162.legacyPackages.${system}.circt}/bin";
           packages = [
             clang-tools
@@ -43,6 +61,7 @@
             nur.xin.nvboard
             nixpkgs-circt162.legacyPackages.${system}.circt
             yosys
+            cli11
           ];
           buildInputs = [
             verilator
@@ -51,7 +70,7 @@
 
           NEMU_HOME="/home/xin/repo/ysyx-workbench/nemu";
         };
-        
+
         # This version (1.43.0) of circt does not exist in nixpkgs
         # and Chisel 5.1.0 specifically build against it, so here we are.
         # Ref: https://github.com/NixOS/nixpkgs/blob/b6465c8/pkgs/development/compilers/circt/default.nix