fis erase {-f flash_address} {-l length}
This command is used to erase a portion of flash memory forcibly. There is no cross-checking to ensure that the area being erased does not correspond to an existing image.
Erase an area of the flash
RedBoot> fis erase -f 0xa0040000 -l 0x20000 ... Erase from 0xa0040000-0xa0060000: .