difftest: do initialization in emu->execute

src/test/csrc/verilator/emu.cpp

@@ -18,6 +18,8 @@
 #include "sdcard.h"
 #include "difftest.h"
 #include "nemuproxy.h"
+#include "goldenmem.h"
+#include "device.h"
 #include <getopt.h>
 #include <signal.h>
 #include <unistd.h>
@@ -229,6 +231,13 @@ inline void Emulator::single_cycle() {
 }
 
 uint64_t Emulator::execute(uint64_t max_cycle, uint64_t max_instr) {
+
+  if (args.enable_diff) {
+    init_goldenmem();
+  }
+  difftest_init();
+  init_device();
+
   uint32_t lasttime_poll = 0;
   uint32_t lasttime_snapshot = 0;
   // const int stuck_limit = 5000;

src/test/csrc/verilator/main.cpp

@@ -17,9 +17,6 @@
 #include <locale.h>
 #include <csignal>
 #include "emu.h"
-#include "difftest.h"
-#include "device.h"
-#include "goldenmem.h"
 
 static char mybuf[BUFSIZ];
 
@@ -40,11 +37,6 @@ int main(int argc, const char** argv) {
   }
 
   auto emu = new Emulator(argc, argv);
-  init_goldenmem();
-  difftest_init();
-
-  // init device
-  init_device();
 
   get_sc_time_stamp = [&emu]() -> double {
     return emu->get_cycles();