I started hacking TheC64 mini last week, and have made great progress into gaining full control of the device. I managed to install and SD card slot and make it boot standard u-boot and Debian. This was all new for me, and was quite fun even though it was quite frustrating.
The SD card install was straight forward, and through the help of a tutorial for the A20-OLinuXino boards, I managed to create a boot-able SD card with the necessary format. The only issue came from the lack of card detect hardware mapping (Don't know what pin its connected to right now), and so it required a workaround to disable the need for card detect. Once that was done, it was finally booting, and greeted me with a Debian shell on both UART and HDMI.
I call this a success, and once the extra ram comes in from eBay, I should be able to attempt to install more ram again (messed up the first install and don't have the necessary tools to re-ball the ram chip). Hopefully SD card support for TheC64 mini is coming soonish.

