feat: export gdbstub api to be used by difftest

nemu/src/isa/riscv32/reg.c

@@ -14,9 +14,10 @@
 ***************************************************************************************/
 
 #include "local-include/reg.h"
-#include "gdbstub.h"
 #include "macro.h"
+#include <difftest-def.h>
 #include <errno.h>
+#include <gdbstub.h>
 #include <isa.h>
 
 const char *regs[] = {"$0", "ra", "sp",  "gp",  "tp", "t0", "t1", "t2",
@@ -76,6 +77,6 @@ int isa_write_reg(void *args, int regno, size_t data) {
   return 0;
 }
 
-arch_info_t isa_arch_info = {.reg_num = 33,
+__EXPORT arch_info_t isa_arch_info = {.reg_num = 32,
                                       .reg_byte = MUXDEF(CONFIG_RV64, 8, 4),
                                       .target_desc = TARGET_RV32};

nemu/src/monitor/filelist.mk

@@ -1,3 +1,4 @@
 DIRS-y += src/monitor
 
 CXXSRC += src/monitor/gdbstub.cc
+LIBS += -lgdbstub

nemu/src/monitor/gdbstub.cc

@@ -4,27 +4,27 @@
 extern "C" {
 #include <cpu/cpu.h>
 #include <debug.h>
+#include <difftest-def.h>
 #include <errno.h>
 #include <gdbstub.h>
 #include <isa.h>
 #include <memory/paddr.h>
 #include <stddef.h>
 #include <stdlib.h>
-}
 
 typedef struct {
   std::vector<breakpoint_t> *bp;
   bool halt;
 } DbgState;
 
-int nemu_read_mem(void *args, size_t addr, size_t len, void *val) {
+__EXPORT int nemu_read_mem(void *args, size_t addr, size_t len, void *val) {
   if (!in_pmem(addr))
     return EINVAL;
   memcpy(val, guest_to_host(addr), len);
   return 0;
 }
 
-int nemu_write_mem(void *args, size_t addr, size_t len, void *val) {
+__EXPORT int nemu_write_mem(void *args, size_t addr, size_t len, void *val) {
   if (!in_pmem(addr))
     return EINVAL;
   memcpy(guest_to_host(addr), val, len);
@@ -35,6 +35,9 @@ static void nemu_is_stopped(gdb_action_t *act, breakpoint_t *stopped_at) {
   switch (nemu_state.state) {
   case NEMU_RUNNING:
     nemu_state.state = NEMU_STOP;
+    if (stopped_at == NULL) {
+      act->reason = gdb_action_t::ACT_NONE;
+    } else {
       switch (stopped_at->type) {
       case BP_SOFTWARE:
         act->reason = gdb_action_t::ACT_BREAKPOINT;
@@ -50,6 +53,7 @@ static void nemu_is_stopped(gdb_action_t *act, breakpoint_t *stopped_at) {
         break;
       }
       act->data = stopped_at->addr;
+    }
     break;
 
   default:
@@ -58,21 +62,21 @@ static void nemu_is_stopped(gdb_action_t *act, breakpoint_t *stopped_at) {
   }
 }
 
-void nemu_cont(void *args, gdb_action_t *res) {
+__EXPORT void nemu_cont(void *args, gdb_action_t *res) {
   DbgState *dbg_state = (DbgState *)args;
   breakpoint_t *stopped_at =
       cpu_exec_with_bp(-1, dbg_state->bp->data(), dbg_state->bp->size());
   nemu_is_stopped(res, stopped_at);
 }
 
-void nemu_stepi(void *args, gdb_action_t *res) {
+__EXPORT void nemu_stepi(void *args, gdb_action_t *res) {
   DbgState *dbg_state = (DbgState *)args;
   breakpoint_t *stopped_at =
       cpu_exec_with_bp(1, dbg_state->bp->data(), dbg_state->bp->size());
   nemu_is_stopped(res, stopped_at);
 }
 
-bool nemu_set_bp(void *args, size_t addr, bp_type_t type) {
+__EXPORT bool nemu_set_bp(void *args, size_t addr, bp_type_t type) {
   DbgState *dbg_state = (DbgState *)args;
   for (const auto &bp : *dbg_state->bp) {
     if (bp.addr == addr && bp.type == type) {
@@ -83,7 +87,7 @@ bool nemu_set_bp(void *args, size_t addr, bp_type_t type) {
   return true;
 }
 
-bool nemu_del_bp(void *args, size_t addr, bp_type_t type) {
+__EXPORT bool nemu_del_bp(void *args, size_t addr, bp_type_t type) {
   DbgState *dbg_state = (DbgState *)args;
   for (auto it = dbg_state->bp->begin(); it != dbg_state->bp->end(); it++) {
     if (it->addr == addr && it->type == type) {
@@ -95,24 +99,44 @@ bool nemu_del_bp(void *args, size_t addr, bp_type_t type) {
   return false;
 }
 
-void nemu_on_interrupt(void *args) {
+__EXPORT void nemu_on_interrupt(void *args) {
   // fputs("Not implemented", stderr);
 }
 
+__EXPORT int nemu_read_reg(void *args, int regno, size_t *data) {
+  return isa_read_reg(args, regno, data);
+}
+__EXPORT int nemu_write_reg(void *args, int regno, size_t data) {
+  return isa_write_reg(args, regno, data);
+}
+__EXPORT size_t argsize = sizeof(DbgState);
+
 static struct target_ops nemu_gdbstub_ops = {.cont = nemu_cont,
                                              .stepi = nemu_stepi,
-                                             .read_reg = isa_read_reg,
-                                             .write_reg = isa_write_reg,
+                                             .read_reg = nemu_read_reg,
+                                             .write_reg = nemu_write_reg,
                                              .read_mem = nemu_read_mem,
                                              .write_mem = nemu_write_mem,
                                              .set_bp = nemu_set_bp,
                                              .del_bp = nemu_del_bp,
                                              .on_interrupt = NULL};
 static DbgState dbg;
-extern "C" {
 static gdbstub_t gdbstub_priv;
 #define SOCKET_ADDR "127.0.0.1:1234"
-int nemu_gdbstub_init() {
+
+__EXPORT void nemu_init(void *args) {
+  DbgState *dbg_state = (DbgState *)args;
+  dbg_state->bp = new std::vector<breakpoint_t>();
+  dbg_state->halt = 0;
+  Assert(dbg_state->bp != NULL, "Failed to allocate breakpoint");
+
+  void init_mem();
+  init_mem();
+  /* Perform ISA dependent initialization. */
+  init_isa();
+}
+
+__EXPORT int nemu_gdbstub_init() {
   dbg.bp = new std::vector<breakpoint_t>();
   assert(dbg.bp);
   if (!gdbstub_init(&gdbstub_priv, &nemu_gdbstub_ops,
@@ -121,7 +145,8 @@ int nemu_gdbstub_init() {
   }
   return 0;
 }
-int nemu_gdbstub_run() {
+
+__EXPORT int nemu_gdbstub_run() {
   puts("Waiting for gdb connection at " SOCKET_ADDR);
   bool success = gdbstub_run(&gdbstub_priv, &dbg);
   gdbstub_close(&gdbstub_priv);

nemu/src/monitor/monitor.c

@@ -25,7 +25,7 @@ void init_mem();
 void init_difftest(char *ref_so_file, long img_size, int port);
 void init_device();
 void init_disasm(const char *triple);
-int nemu_gdbstub_init();
+void nemu_init();
 
 static void welcome() {
   Log("Trace: %s", MUXDEF(CONFIG_TRACE, ANSI_FMT("ON", ANSI_FG_GREEN),
@@ -60,7 +60,8 @@ static long load_img() {
   // Image file is searched from paths in environment variable NEMU_IMAGES_PATH if it's a relative path
   if (img_file[0] != '/') {
     char *search_paths = getenv("NEMU_IMAGES_PATH");
-    if(search_paths == NULL) search_paths = "./";
+    if (search_paths == NULL)
+      search_paths = "./";
     search_paths = strdup(search_paths);
     Trace("NEMU_IMAGES_PATH=%s", search_paths);
 
@@ -68,8 +69,10 @@ static long load_img() {
     char *p_start = search_paths;
     do {
       char *p = strchr(p_start, ':');
-      if (p != NULL) *p = '\0';
-      else p = paths_end;
+      if (p != NULL)
+        *p = '\0';
+      else
+        p = paths_end;
 
       char *file_path = malloc(p - p_start + img_filename_len + 2);
       strcpy(file_path, p_start);
@@ -86,7 +89,7 @@ static long load_img() {
 
       Assert(fp != NULL || errno == ENOENT, "Cannot open '%s'", img_file);
       p_start = p + 1;
-    } while(p_start < paths_end);
+    } while (p_start < paths_end);
     free(search_paths);
 
     Assert(fp, "Cannot find '%s'", img_file);
@@ -178,10 +181,11 @@ void init_monitor(int argc, char *argv[]) {
   init_difftest(diff_so_file, img_size, difftest_port);
 
   /* Initialize debugger */
-  if (nemu_gdbstub_init()) {
-    Error("Failed to init");
-    exit(1);
-  }
+  // if (nemu_init()) {
+  //   Error("Failed to init");
+  //   exit(1);
+  // }
+  nemu_init();
 
   // printf("elf_file: %s\n", elf_file);
   if (elf_file != NULL) {