GDB exit status for semihosting

Report exit status to GDB when a semihosted application exits.
Signed-off-by: NPaul Brook <paul@codesourcery.com>

arm-semi.c

@@ -459,6 +459,7 @@ uint32_t do_arm_semihosting(CPUState *env)
             return 0;
         }
     case SYS_EXIT:
+        gdb_exit(env, 0);
         exit(0);
     default:
         fprintf(stderr, "qemu: Unsupported SemiHosting SWI 0x%02x\n", nr);

gdbstub.c

@@ -2373,6 +2373,26 @@ static void gdb_read_byte(GDBState *s, int ch)
     }
 }
 
+/* Tell the remote gdb that the process has exited.  */
+void gdb_exit(CPUState *env, int code)
+{
+  GDBState *s;
+  char buf[4];
+
+  s = gdbserver_state;
+  if (!s) {
+      return;
+  }
+#ifdef CONFIG_USER_ONLY
+  if (gdbserver_fd < 0 || s->fd < 0) {
+      return;
+  }
+#endif
+
+  snprintf(buf, sizeof(buf), "W%02x", (uint8_t)code);
+  put_packet(s, buf);
+}
+
 #ifdef CONFIG_USER_ONLY
 int
 gdb_queuesig (void)
@@ -2436,20 +2456,6 @@ gdb_handlesig (CPUState *env, int sig)
   return sig;
 }
 
-/* Tell the remote gdb that the process has exited.  */
-void gdb_exit(CPUState *env, int code)
-{
-  GDBState *s;
-  char buf[4];
-
-  s = gdbserver_state;
-  if (gdbserver_fd < 0 || s->fd < 0)
-    return;
-
-  snprintf(buf, sizeof(buf), "W%02x", code);
-  put_packet(s, buf);
-}
-
 /* Tell the remote gdb that the process has exited due to SIG.  */
 void gdb_signalled(CPUState *env, int sig)
 {

gdbstub.h

@@ -17,10 +17,10 @@ typedef void (*gdb_syscall_complete_cb)(CPUState *env,
 void gdb_do_syscall(gdb_syscall_complete_cb cb, const char *fmt, ...);
 int use_gdb_syscalls(void);
 void gdb_set_stop_cpu(CPUState *env);
+void gdb_exit(CPUState *, int);
 #ifdef CONFIG_USER_ONLY
 int gdb_queuesig (void);
 int gdb_handlesig (CPUState *, int);
-void gdb_exit(CPUState *, int);
 void gdb_signalled(CPUState *, int);
 void gdbserver_fork(CPUState *);
 #endif

m68k-semi.c

@@ -172,6 +172,7 @@ void do_m68k_semihosting(CPUM68KState *env, int nr)
     args = env->dregs[1];
     switch (nr) {
     case HOSTED_EXIT:
+        gdb_exit(env, env->dregs[0]);
         exit(env->dregs[0]);
     case HOSTED_OPEN:
         if (use_gdb_syscalls()) {