Introduce support for NuttX RTOS (#377)

Signed-off-by: Huang Qi <huangqi3@xiaomi.com>

Co-authored-by: Huang Qi <huangqi3@xiaomi.com>

core/shared/platform/nuttx/nuttx_platform.c

@@ -0,0 +1,70 @@
+/*
+ * Copyright (C) 2020 XiaoMi Corporation.  All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+ */
+
+#include "platform_api_extension.h"
+#include "platform_api_vmcore.h"
+
+int
+bh_platform_init()
+{
+    return 0;
+}
+
+void
+bh_platform_destroy()
+{}
+
+void *
+os_malloc(unsigned size)
+{
+    return malloc(size);
+}
+
+void *
+os_realloc(void *ptr, unsigned size)
+{
+    return realloc(ptr, size);
+}
+
+void
+os_free(void *ptr)
+{
+    free(ptr);
+}
+
+void *
+os_mmap(void *hint, size_t size, int prot, int flags)
+{
+    if ((uint64)size >= UINT32_MAX)
+        return NULL;
+    return malloc((uint32)size);
+}
+
+void
+os_munmap(void *addr, size_t size)
+{
+    return free(addr);
+}
+
+int
+os_mprotect(void *addr, size_t size, int prot)
+{
+    return 0;
+}
+
+void
+os_dcache_flush()
+{}
+
+uint64
+os_time_get_boot_microsecond()
+{
+    struct timespec ts;
+    if (clock_gettime(CLOCK_MONOTONIC, &ts) != 0) {
+        return 0;
+    }
+
+    return ((uint64)ts.tv_sec) * 1000 * 1000 + ((uint64)ts.tv_nsec) / 1000;
+}

core/shared/platform/nuttx/nuttx_thread.c

@@ -0,0 +1,86 @@
+/*
+ * Copyright (C) 2020 XiaoMi Corporation.  All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+ */
+
+#include "platform_api_extension.h"
+#include "platform_api_vmcore.h"
+
+korp_tid
+os_self_thread()
+{
+    return (korp_tid)pthread_self();
+}
+
+int
+os_mutex_init(korp_mutex *mutex)
+{
+    return pthread_mutex_init(mutex, NULL) == 0 ? BHT_OK : BHT_ERROR;
+}
+
+int
+os_mutex_destroy(korp_mutex *mutex)
+{
+    int ret;
+
+    assert(mutex);
+    ret = pthread_mutex_destroy(mutex);
+
+    return ret == 0 ? BHT_OK : BHT_ERROR;
+}
+
+int
+os_mutex_lock(korp_mutex *mutex)
+{
+    int ret;
+
+    assert(mutex);
+    ret = pthread_mutex_lock(mutex);
+    if (0 != ret) {
+        os_printf("vm mutex lock failed (ret=%d)!\n", ret);
+        exit(-1);
+    }
+    return ret;
+}
+
+int
+os_mutex_unlock(korp_mutex *mutex)
+{
+    int ret;
+
+    assert(mutex);
+    ret = pthread_mutex_unlock(mutex);
+    if (0 != ret) {
+        os_printf("vm mutex unlock failed (ret=%d)!\n", ret);
+        exit(-1);
+    }
+    return ret;
+}
+
+uint8 *
+os_thread_get_stack_boundary()
+{
+    return NULL;
+}
+
+int
+os_cond_init(korp_cond *cond)
+{
+    assert(cond);
+
+    if (pthread_cond_init(cond, NULL) != BHT_OK)
+        return BHT_ERROR;
+
+    return BHT_OK;
+}
+
+int
+os_cond_destroy(korp_cond *cond)
+{
+    assert(cond);
+
+    if (pthread_cond_destroy(cond) != BHT_OK)
+        return BHT_ERROR;
+
+    return BHT_OK;
+}

core/shared/platform/nuttx/platform_internal.h

@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) 2020 XiaoMi Corporation.  All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+ */
+
+#ifndef _PLATFORM_INTERNAL_H
+#define _PLATFORM_INTERNAL_H
+
+#include <ctype.h>
+#include <errno.h>
+#include <inttypes.h>
+#include <limits.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef BH_PLATFORM_NUTTX
+#define BH_PLATFORM_NUTTX
+#endif
+
+typedef pthread_t korp_tid;
+typedef pthread_mutex_t korp_mutex;
+typedef pthread_cond_t korp_cond;
+typedef pthread_t korp_thread;
+
+#define BH_APPLET_PRESERVED_STACK_SIZE (2 * BH_KB)
+
+/* Default thread priority */
+#define BH_THREAD_DEFAULT_PRIORITY 100
+
+#define os_printf  printf
+#define os_vprintf vprintf
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* end of _BH_PLATFORM_H */

core/shared/platform/nuttx/shared_platform.cmake

@@ -0,0 +1,14 @@
+# Copyright (C) 2020 XiaoMi Corporation.  All rights reserved.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+set (PLATFORM_SHARED_DIR ${CMAKE_CURRENT_LIST_DIR})
+
+add_definitions(-DBH_PLATFORM_NUTTX)
+
+include_directories(${PLATFORM_SHARED_DIR})
+include_directories(${PLATFORM_SHARED_DIR}/../include)
+
+file (GLOB_RECURSE source_all ${PLATFORM_SHARED_DIR}/*.c)
+
+set (PLATFORM_SHARED_SOURCE ${source_all} ${PLATFORM_COMMON_MATH_SOURCE})
+