添加rtthread相关代码

riscv/rtthread/include/rtm.h

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2006-2021, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ */
+
+#ifndef __RTM_H__
+#define __RTM_H__
+
+#include <rtdef.h>
+#include <rtthread.h>
+
+#ifdef RT_USING_MODULE
+struct rt_module_symtab
+{
+    void       *addr;
+    const char *name;
+};
+
+#if defined(_MSC_VER)
+#pragma section("RTMSymTab$f",read)
+#define RTM_EXPORT(symbol)                                            \
+__declspec(allocate("RTMSymTab$f"))const char __rtmsym_##symbol##_name[] = "__vs_rtm_"#symbol;
+#pragma comment(linker, "/merge:RTMSymTab=mytext")
+
+#elif defined(__MINGW32__)
+#define RTM_EXPORT(symbol)
+
+#else
+#define RTM_EXPORT(symbol)                                            \
+const char __rtmsym_##symbol##_name[] rt_section(".rodata.name") = #symbol;     \
+const struct rt_module_symtab __rtmsym_##symbol rt_section("RTMSymTab")= \
+{                                                                     \
+    (void *)&symbol,                                                  \
+    __rtmsym_##symbol##_name                                          \
+};
+#endif
+
+#else
+#define RTM_EXPORT(symbol)
+#endif
+
+#endif