Hello,
I have successfully installed Openwrt on Cisco ON-100 platform, that is Marvell Kirkwood (1,6Ghz), 512MB DDR3 RAM, 512MB NAND Flash, 2x 1Gbps ethernet interfaces (one with PoE), 1x USB port, SD-CARD slot, no WIFI interfaces.
Have a look at the description over here:
http://www.filedropper.com/ciscoon100-openwrt-howto
Product video:
https://www.youtube.com/watch?v=FwP2kTn9WgM
Thanks,
Tom.