* about 1MB (2040 blocks), Env is stored after the image, and the env size is
* 0x2000 (16 blocks), 8 + 2040 + 16 = 2064, enlarge it to 18432(0x4800).
*/
* about 1MB (2040 blocks), Env is stored after the image, and the env size is
* 0x2000 (16 blocks), 8 + 2040 + 16 = 2064, enlarge it to 18432(0x4800).
*/