Buffalo WHR-AMG54

Overview
On wifi.com.cn (internal images)
 * "WHR4-AG54A REV: XC" and a date code of 0542 is silkscreened on the board.
 * The format would seem to indicate CyberTAN manuf

Links of Interest
On the OpenWrt forums

Buffalo WHR-G54S、WHR-HP-G54、WHR-AMG54、WHR-AM54G54 Firm On the DD-WRT Forum

Per the DD-WRT Supported Devices table, you can use the WHR-HP-G54 firmware.

Flashing dd-wrt
Supported by dd-wrt as of = v24 sp2

use firmware for WHR-HP-G54

Please insert instructions here

Pictures
Images from wifi.com.cn