sw: Fixed wrong return value when using ocd semihosting (#165)

Co-authored-by: Germain Haugou <[email protected]>

sw/snRuntime/src/openocd.h

@@ -5,6 +5,11 @@
 
 #include <stdint.h>
 
+#pragma once
+
+#define SEMIHOST_EXIT_SUCCESS 0x20026
+#define SEMIHOST_EXIT_ERROR 0x20023
+
 /* riscv semihosting standard:
  * IN: a0 holds syscall number
  * IN: a1 holds pointer to arg struct
@@ -32,3 +37,8 @@ static inline int __ocd_semihost_write(int fd, uint8_t *buffer, int len) {
     __asm__ __volatile__("" : : : "memory");
     return __ocd_semihost(0x05, (long)args);
 }
+
+static inline void __ocd_semihost_exit(int status) {
+    __ocd_semihost(0x18,
+                   status == 0 ? SEMIHOST_EXIT_SUCCESS : SEMIHOST_EXIT_ERROR);
+}

sw/snRuntime/src/start.c

@@ -2,6 +2,10 @@
 // Licensed under the Apache License, Version 2.0, see LICENSE for details.
 // SPDX-License-Identifier: Apache-2.0
 
+#ifdef OPENOCD_SEMIHOSTING
+#include "openocd.h"
+#endif
+
 #ifdef SNRT_INIT_CLS
 static inline uint32_t snrt_cls_base_addr() {
     extern volatile uint32_t __cdata_start, __cdata_end;
@@ -100,7 +104,7 @@ static inline void snrt_init_libs() { snrt_alloc_init(); }
 static inline void snrt_exit_default(int exit_code) {
     exit_code = snrt_global_all_to_all_reduction(exit_code);
 #ifdef OPENOCD_SEMIHOSTING
-    if (snrt_global_core_idx() == 0) __ocd_semihost(0x18, (long)exit_code);
+    if (snrt_global_core_idx() == 0) __ocd_semihost_exit(exit_code);
 #else
     if (snrt_global_core_idx() == 0)
         *(snrt_exit_code_destination()) = (exit_code << 1) | 1;