Implement native function pointer check, addr conversion and register, update documents (#185)

Modified WASM runtime API:
- wasm_runtime_module_malloc()
- wasm_runtime_lookup_function()
Introduced runtime API
- wasm_runtime_register_natives()

core/shared/include/config.h

@@ -80,6 +80,10 @@ enum {
 #define WASM_ENABLE_BASE_LIB 0
 #endif
 
+#ifndef WASM_ENABLE_APP_FRAMEWORK
+#define WASM_ENABLE_APP_FRAMEWORK 0
+#endif
+
 /* WASM log system */
 #ifndef WASM_ENABLE_LOG
 #define WASM_ENABLE_LOG 1
@@ -148,8 +152,8 @@ enum {
 #define APP_THREAD_STACK_SIZE_MIN (16 * 1024)
 #define APP_THREAD_STACK_SIZE_MAX (256 * 1024)
 #else
-#define APP_THREAD_STACK_SIZE_DEFAULT (4 * 1024)
-#define APP_THREAD_STACK_SIZE_MIN (2 * 1024)
+#define APP_THREAD_STACK_SIZE_DEFAULT (6 * 1024)
+#define APP_THREAD_STACK_SIZE_MIN (4 * 1024)
 #define APP_THREAD_STACK_SIZE_MAX (256 * 1024)
 #endif
 

core/shared/platform/zephyr/bh_platform.c

@@ -91,7 +91,7 @@ bh_mprotect(void *addr, uint32 size, int prot)
 void
 bh_dcache_flush()
 {
-#if defined(CONFIG_CPU_CORTEX_M7)
+#if defined(CONFIG_CPU_CORTEX_M7) && defined(CONFIG_ARM_MPU)
     uint32 key;
     key = irq_lock();
     SCB_CleanDCache();