[rt-smart] kernel virtual memory management layer (#6809)

synchronize virtual memory system works.
adding kernel virtual memory management layer for page-based MMU enabled architecture
porting libcpu MMU codes
porting lwp memory related codes

include/rtdef.h

@@ -356,7 +356,9 @@ typedef int (*init_fn_t)(void);
 #define RT_EIO                          8               /**< IO error */
 #define RT_EINTR                        9               /**< Interrupted system call */
 #define RT_EINVAL                       10              /**< Invalid argument */
-#define RT_ETRAP                        11              /**< trap event */
+#define RT_ETRAP                        11              /**< Trap event */
+#define RT_ENOENT                       12              /**< No entry */
+#define RT_ENOSPC                       13              /**< No space left */
 
 /**@}*/
 

include/rthw.h

@@ -54,6 +54,11 @@ enum RT_HW_CACHE_OPS
  * CPU interfaces
  */
 #ifdef RT_USING_CACHE
+
+#ifdef ARCH_RISCV64
+#include <cache.h>
+#endif
+
 void rt_hw_cpu_icache_enable(void);
 void rt_hw_cpu_icache_disable(void);
 rt_base_t rt_hw_cpu_icache_status(void);