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.