2. Modify the return code to -1 when failed 3. Change the mounting filesystem from ramfs to sdcard 4. Replace RT_USING_RTGUI with PKG_USING_GUIENGINE and remove RT_USING_FTK
2. Modify the return code to -1 when failed 3. Change the mounting filesystem from ramfs to sdcard 4. Replace RT_USING_RTGUI with PKG_USING_GUIENGINE and remove RT_USING_FTK