RedBoot> fis free
  0xA8730000 .. 0xA87E0000
RedBoot>

ubuntu@ubuntu-laptop:~/openwrt/atheros$ bc
bc 1.06
Copyright 1991-1994, 1997, 1998, 2000 Free Software Foundation, Inc.
This is free software with ABSOLUTELY NO WARRANTY.
For details type `warranty'. 
obase=16
ibase=16
A87E0000 - A8730000
B0000
ubuntu@ubuntu-laptop:~/openwrt/atheros$ 

RedBoot> fis init                                                                                     
About to initialize [format] FLASH image system - continue (y/n)? y                                   
*** Initialize FLASH Image System                                                                     
... Erase from 0xa87e0000-0xa87f0000: .                                                               
... Program from 0x80ff0000-0x81000000 at 0xa87e0000: .                                               
RedBoot> load -r -v -b %{FREEMEMLO} rootfs -m ymodem                                                  
CRaw file loaded 0x80040800-0x801e07ff, assumed entry at 0x80040800                                   
xyzModem - CRC mode, 13314(SOH)/0(STX)/0(CAN) packets, 3 retries                                      
RedBoot> fis create -l 0xB0000 rootfs                                                                 
... Erase from 0xa8030000-0xa80e0000: ...........                                                     
... Program from 0x80040800-0x801e0800 at 0xa8030000: ..........................                      
... Erase from 0xa87e0000-0xa87f0000: .                                                               
... Program from 0x80ff0000-0x81000000 at 0xa87e0000: .                                               
RedBoot> load -r -v -b %{FREEMEMLO} vmlinux -m ymodem                                                 
CRaw file loaded 0x80040800-0x801007ff, assumed entry at 0x80040800                                   
xyzModem - CRC mode, 6146(SOH)/0(STX)/0(CAN) packets, 3 retries                                       
RedBoot> fis create -r 0x80041000 -e 0x80041000 vmlinux.bin.l7                                        
... Erase from 0xa80e0000-0xa81a0000: ............                                                    
... Program from 0x80040800-0x80100800 at 0xa80e0000: ............                                    
... Erase from 0xa87e0000-0xa87f0000: .                                                               
... Program from 0x80ff0000-0x81000000 at 0xa87e0000: .                                               
RedBoot> reset