Merge branch 'fix-difftest' into 'rv64'

Fix difftest

See merge request projectn/nemu!5

src/device/argsrom.c

-#include "common.h"
-#include "device/map.h"
-
-#define ARGSROM_MMIO 0xa2000000
-
-static uint8_t *argsrom_base;
-char* get_mainargs(void);
-
-void init_argsrom() {
-  argsrom_base = new_space(4096);
-  strcpy((char *)argsrom_base, get_mainargs());
-  add_mmio_map("argsrom", ARGSROM_MMIO, argsrom_base, 4096, NULL);
-}

src/device/device.c

 #include "common.h"
 
-void init_argsrom();
-
 #ifdef HAS_IOE
 
 #include <sys/time.h>
@@ -65,7 +63,6 @@ void sdl_clear_event_queue() {
 }
 
 void init_device() {
-  init_argsrom();
   init_serial();
   init_timer();
   init_vga();
@@ -85,7 +82,6 @@ void init_device() {
 #else
 
 void init_device() {
-  init_argsrom();
 }
 
 #endif	/* HAS_IOE */

src/monitor/diff-test/diff-test.c

@@ -17,6 +17,14 @@ static bool is_detach = false;
 void difftest_skip_ref() {
   if (is_detach) return;
   is_skip_ref = true;
+  // If such an instruction is one of the instruction packing in QEMU
+  // (see below), we end the process of catching up with QEMU's pc to
+  // keep the consistent behavior in our best.
+  // Note that this is still not perfect: if the packed instructions
+  // already write some memory, and the incoming instruction in NEMU
+  // will load that memory, we will encounter false negative. But such
+  // situation is infrequent.
+  skip_dut_nr_instr = 0;
 }
 
 // this is used to deal with instruction packing in QEMU.
@@ -70,6 +78,8 @@ void init_difftest(char *ref_so_file, long img_size) {
 
   ref_difftest_init();
   ref_difftest_memcpy_from_dut(PC_START, guest_to_host(IMAGE_START), img_size);
+  char *mainargs = guest_to_host(0);
+  ref_difftest_memcpy_from_dut(PC_START - IMAGE_START, mainargs, strlen(mainargs) + 1);
   ref_difftest_setregs(&cpu);
 }
 

src/monitor/monitor.c

@@ -55,6 +55,9 @@ static inline long load_img() {
     assert(ret == 1);
 
     fclose(fp);
+
+    // mainargs
+    strcpy(guest_to_host(0), mainargs);
   }
   return size;
 }
@@ -77,10 +80,6 @@ static inline void parse_args(int argc, char *argv[]) {
   }
 }
 
-char* get_mainargs(void) {
-  return mainargs;
-}
-
 int init_monitor(int argc, char *argv[]) {
   /* Perform some global initialization. */