This command is used to write-protect (lock) a portion of flash memory, to prevent accidental overwriting of images. In order to make any modifications to the flash, a matching fis unlock command must be issued. This command is optional and will only be provided on hardware which can support write-protection of the flash space.
Note: Depending on the system, attempting to write to write-protected flash may generate errors or warnings, or be benignly quiet.
Lock an area of the flash
RedBoot> fis lock -f 0xa0040000 -l 0x20000 ... Lock from 0xa0040000-0xa0060000: .