[U-Boot] [U-boot] monitor length question

[TigerLiu at viatech.com.cn]

Hi, experts:
I am studying u-boot latest code now.
I have a question about monitor length.
1. in board_init_f() function in arch\arm\lib\board.c
   Gd->mon_len = _bss_end_ofs;
2. in board_init_r() function in arch\arm\lib\board.c
　　Monitor_flash_len = _end_ofs;

Because _end_ofs < _bss_end_ofs, so it confused me!
Why need to discard some data when re-calculating monitor_in board_init_r() function.
Best wishes,