Cisco 877W recover IOS using tftpdnld from ROMMON

256M memory, 36M (20+16) flash

1. get IOS and setup a TFTP server
2. connect the TFTP server DIRECT to a FE port of  877W using a cat5 cable
3. go into rommon mode by hit "ctrl + Break"
4. delete old IOS from flash
rommon 1 >delete flash:c870-adventerprisek9-mz.150-1.XA4.bin
Are you sure you want to delete "flash:c870-adventerprisek9-mz.150-1.XA4.bin" (y
/n)?y
Delete operation will take approximately 37 to 940 seconds

5. issue continually ping from TFTP to 877W (e.g. ping -t 192.168.1.1)
6. configure IP so 877W can reach the TFTP server
rommon 1 >IP_ADDRESS=192.168.1.1
rommon 1 >TFTP_SERVER=192.168.1.2
rommon 1 >TFTP_FILE=c870-advipservicesk9-mz.124-15.XY3.bin
rommon 1 >IP_SUBNET_MASK=255.255.255.0
rommon 1 >DEFAULT_GATEWAY=192.168.1.2
rommon 1 >tftpdnld
***********check the result, you want all escalation mark - !!!!!!; anything else means fail************

7.configure to boot from now IOS
rommon 1 >BOOT=flash:c870-advipservicesk9-mz.124-15.XY3.bin
8. reset

Tips: be patient, it took me several times to get it right.
Make sure NO other interferences such as TV; USB HD, PCs, mobile, etc.

I once got below error and ping (procedure 5) fixed it

Receiving c870-advipservicesk9-mz.151-3.T.bin from 192.168.2.28 !!!!!!!!!!!!!!!!
!!!!!!!!!!!!
ARP: address resolution for 192.168.2.1 timed out.
ARP failed with failure code 3.  TFTP transfer aborted.
TFTP: Operation terminated prematurely.

Ref:http://www.cisco.com/en/US/products/hw/routers/ps259/products_tech_note09186a008015bf9e.shtml
http://bayupw.blogspot.com/2008/08/recover-ios-using-tftpdnld-from-rommon.html