They presented this at FOSDEM today, and ran the entire presentation (and a demo afterwards) on the actual hardware. They used PCI via an FPGA to interface with a standard ATI gfx card iirc. I don't know if the video is out yet, but have a look!

No video yet that i can find, but it seem the slides are available.

https://fosdem.org/2018/schedule/event/riscv/

That's what I hoped could be done. Did they use an open source ATI driver compiled for risc-v? That would make for a very interesting development rig.

The page mentions an FMC connector for future expansion, a standard FPGA expansion interface supplying 34 to 160 10Gb/s signals.† I don't know about varieties and compatibility, but Hitec makes a great number of interface cards for it, including an 8 lane PCI Express.‡

␄

† https://en.wikipedia.org/wiki/FPGA_Mezzanine_Card

‡ http://www.hitechglobal.com/Accessories/FMC_Modules.htm

I wonder what signals they actually route out the FMC card. The website doesn't give a lot of information, but it seems like probably just ChipLink which they claim is their serialized TileLink bus protocol. So, you probably wouldn't be able to just plug a low-cost FMC module into the board. But with something like https://www.xilinx.com/products/boards-and-kits/ek-s6-sp605-... for another $500, you could theoretically use the DVI connector to provide a framebuffer, the PCI connector to interface to an NVME drive, and the FPGA to implement the logic of a TileLink endpoint as well as a minimal framebuffer and PCIe root complex.

ChipLink is indeed routed out to the FMC. The demo during FOSDEM was done with a FPGA card attached to the FMC which then drove additional peripherals.

Jack, SiFive

The instructions for some of the previous dev kits point to "known good" FMC compatible adapters.

The one that caught my interest right away is the PCIe module:

http://www.hitechglobal.com/FMCModules/FMC_PCIExpress.htm

There's also a PCIe expansion that works with it, so increase the number of slots to five:

https://www.onestopsystems.com/product/%C2%B5cube3-expansion...

With those, it seems like enough to test out development for storage applications. eg NAS, etc.

There must be a UART because there's a FT223H and USB port at the top left.

For a FT232H on early development hardware, my first thought would be JTAG, not UART. Could be both if it's a '2232, though.

That micro port may only be for power.

Or perhaps a client port to allow a PC to talk to the board without a network connection.

Yeah, that's totally a console port. The micro-B device connector gives that away.