Copies memory (RAM, ROM, FLASH, etc) from one area to another.
Examples
Copy 16 bits at a time.
RedBoot> mfill -b 0x100000 -l 0x20 -2 -p 0xDEAD
RedBoot> mfill -b 0x200000 -l 0x20 -2 -p 0x0
RedBoot> dump -b 0x200000 -l 0x20 -2
00200000: 0000 0000 0000 0000 0000 0000 0000 0000
00200010: 0000 0000 0000 0000 0000 0000 0000 0000
RedBoot> mcopy -s 0x100000 -d 0x200000 -2 -l 0x20
RedBoot> dump -b 0x200000 -l 0x20 -2
00200000: DEAD DEAD DEAD DEAD DEAD DEAD DEAD DEAD
00200010: DEAD DEAD DEAD DEAD DEAD DEAD DEAD DEAD