That will help you:
1.) Download the APBoot-Image from Aruba Networks
Download Software -> AP Boot Image -> AP-12x
filename: ap12x-1.0.0.9-18209.ari
(If you are not able to download it, ask Aruba TAC if you can get it, I am not sure if I am allowed to give it to you.)
2.) Place the file into a TFTP-Server (root-level)
3.) Connect to the AP-12x and via console
Connect an Cable to ETH0
4.) Boot the AP and stop the autoboot hitting ENTER.
5.) Request a DHCP-Paket manually
apboot> dhcp
OR
set the ip addess manually
setenv ipaddr <addr>
setenv netmask <mask>
setenv gatewayip <gateway>
save
(You can test the connectivity to the TFTP-Server via a ping command after that.)
6.) Upgrade the boot image
apboot> upgrade boot <ip_tftp_server>:<filename>
e.g. apboot> upgrade boot 192.168.10.10:ap12x-1.0.0.9-18209.ari
7.) boot the ap
apboot> boot
I attached the technical bulletin.
Regards,
Thomas