add malloc, realloc etc implementation in minilibc.

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@1452 bbd45198-f89e-11dd-88c7-29a3b14d5316

components/libc/minilibc/stdlib.c

@@ -38,4 +38,24 @@ int atoi(const char* s)
 	return sign==-1?-v:v;
 }
 
+void *malloc(size_t size)
+{
+	return rt_malloc(size);
+}
+
+void free(void *ptr)
+{
+	rt_free(ptr);
+}
+
+void *realloc(void *ptr, size_t size)
+{
+	return rt_realloc(ptr, size);
+}
+
+void *calloc(size_t nelem, size_t elsize)
+{
+	return rt_calloc(nelem, elsize);
+}
+
 #endif