move basic device handling to verilator by DPI

* TODO: implement keyboard and vga

src/test/csrc/common.h

@@ -4,6 +4,8 @@
 #include <cstdio>
 #include <cstring>
 #include <cstdlib>
+#include <stdint.h>
+#include <assert.h>
 
 #ifdef __cplusplus
 # include <stdexcept>

src/test/csrc/device.cpp

+#include "common.h"
+#include <sys/time.h>
+
+static struct timeval boot = {};
+
+void device_init(void) {
+  gettimeofday(&boot, NULL);
+}
+
+uint32_t uptime(void) {
+  struct timeval t;
+  gettimeofday(&t, NULL);
+
+  int s = t.tv_sec - boot.tv_sec;
+  int us = t.tv_usec - boot.tv_usec;
+  if (us < 0) {
+    s --;
+    us += 1000000;
+  }
+
+  return s * 1000 + (us + 500) / 1000;
+}
+
+extern "C" void device_helper(
+    uint8_t req_wen, uint32_t req_addr, uint32_t req_wdata, uint32_t *resp_rdata) {
+  switch (req_addr) {
+      // read uartlite stat register
+    case 0x40600008:
+      // read uartlite ctrl register
+    case 0x4060000c: *resp_rdata = 0; break;
+      // write uartlite data register
+    case 0x40600004: if (req_wen) eprintf("%c", (uint8_t)req_wdata); break;
+      // read RTC
+    case 0x40700000: *resp_rdata = uptime(); break;
+      // read key
+    case 0x40900000: *resp_rdata = 0; break;
+      // read screen size
+    case 0x40800000: *resp_rdata = 0; break;
+      // write vga sync
+    case 0x40800004: *resp_rdata = 0; break;
+    default:
+      if (req_addr >= 0x40000000 && req_addr < 0x40400000 && req_wen) {
+        // write to vmem
+      }
+      else {
+        assert(0);
+      }
+  }
+}

src/test/csrc/main.cpp

@@ -90,10 +90,13 @@ int main(int argc, const char** argv) {
     return emu.get_cycles();
   };
 
-  struct timeval t0, t1;
-  gettimeofday(&t0, NULL);
+  extern void device_init(void);
+  device_init();
+
   auto timeout = emu.execute();
-  gettimeofday(&t1, NULL);
+
+  extern uint32_t uptime(void);
+  uint32_t ms = uptime();
 
   if (timeout) {
     eprintf(ANSI_COLOR_RED "Timeout after %lld cycles\n" ANSI_COLOR_RESET, (long long)emu.get_max_cycles());
@@ -101,13 +104,7 @@ int main(int argc, const char** argv) {
     extern void display_trapinfo(void);
     display_trapinfo();
 
-    int s = t1.tv_sec - t0.tv_sec;
-    int us = t1.tv_usec - t0.tv_usec;
-    if (us < 0) {
-      s --;
-      us += 1000000;
-    }
-    eprintf(ANSI_COLOR_BLUE "Host time spent: %ds %6dus\n" ANSI_COLOR_RESET, s, us);
+    eprintf(ANSI_COLOR_BLUE "Host time spent: %dms\n" ANSI_COLOR_RESET, ms);
   }
 
   return timeout;

src/test/scala/top/SimMMIO.scala

@@ -5,6 +5,17 @@ import chisel3.util._
 
 import bus.simplebus.SimpleBus
 
+class DeviceHelper extends BlackBox {
+  val io = IO(new Bundle {
+    val clk = Input(Clock())
+    val reqValid = Input(Bool())
+    val reqWen = Input(Bool())
+    val reqAddr = Input(UInt(32.W))
+    val reqWdata = Input(UInt(32.W))
+    val respRdata = Output(UInt(32.W))
+  })
+}
+
 class SimMMIO extends Module {
   val io = IO(new Bundle {
     val rw = Flipped(new SimpleBus)
@@ -22,6 +33,18 @@ class SimMMIO extends Module {
   io.mmioTrap.valid := false.B
   io.mmioTrap.cmd := 0.U
 
+  val helper = Module(new DeviceHelper)
+  helper.io.clk := clock
+  helper.io.reqValid := io.rw.req.valid
+  helper.io.reqWen := wen
+  helper.io.reqAddr := io.rw.req.bits.addr
+  helper.io.reqWdata := io.rw.req.bits.wdata
+  io.rw.resp.bits.rdata := helper.io.respRdata
+
+  io.rw.req.ready := true.B
+  io.rw.resp.valid := io.rw.req.valid
+
+/*
   when (io.rw.req.valid) {
     switch (io.rw.req.bits.addr) {
       is (0x40600008.U) {
@@ -67,10 +90,11 @@ class SimMMIO extends Module {
       io.mmioTrap.cmd := 5.U
     }
   }
+  */
 
-  io.rw.req.ready := true.B
-  io.rw.resp.bits.rdata := io.mmioTrap.rdata
-  io.rw.resp.valid := io.mmioTrap.valid
+  //io.rw.req.ready := true.B
+  //io.rw.resp.bits.rdata := io.mmioTrap.rdata
+  //io.rw.resp.valid := io.mmioTrap.valid
 
-  assert(!io.rw.req.valid || io.mmioTrap.valid, "bad addr = 0x%x", io.rw.req.bits.addr)
+  //assert(!io.rw.req.valid || io.mmioTrap.valid, "bad addr = 0x%x", io.rw.req.bits.addr)
 }

src/test/vsrc/device.v

+import "DPI-C" function void device_helper
+(
+  input  bit    req_wen,
+  input  int    req_addr,
+  input  int    req_wdata,
+  output int    resp_rdata
+);
+
+module DeviceHelper(
+  input         clk,
+  input         reqValid,
+  input         reqWen,
+  input  [31:0] reqAddr,
+  input  [31:0] reqWdata,
+  output [31:0] respRdata
+);
+
+  always @(posedge clk) begin
+    if (reqValid) device_helper(reqWen, reqAddr, reqWdata, respRdata);
+  end
+
+endmodule