Help needed: AirTight C-55 initramfs image

[packet6868]

Hi,

I am new to OpenWrt and need some help with image flashing.

I got my hands on an old AirTight C-55 WiFi Access Point with (useless) factory image and would like to flash it with OpenWrt. The problem is I don't know which image I can use to initially flash it with (so I can finally install sysupgrade image).

I followed the process described here:

AirTight C-55: OpenWrt installation method

Hi! I'm trying to understand how to install OpenWRT binary onto AirTight C-55 hardware. Sadly I was not able to find enough information about the process. C-55 does not try to access TFTP server during boot, U-Boot doesnt allow to interrupted the boot process through console, so I'm a bit frustrated. Search in the forum topics gives only a few posts without the necessary information. Maybe somebody, who have already succesfully reflashed this AP, will point me the right direction? …

but could not find the initramfs image referenced there (only sysupgrade image available).
I tried multiple factory images for ar71xx but none worked.

Any help much appreciated!