[imstate]

currently the PCIe card would need some kind of driver to be written on the OS to communicate with it.

There's SoC devices that have a soft processor on it that runs a linux kernel and can communicate with the FPGA.

[mikepurvis]

Are many of those devices actually reprogramming the FPGA at runtime from the OS running on the soft processor, though?

My impression was that you tended to define pretty static blocks of functionality (you know, hash calculators for your bitcoin mining or whatever), and then just communicate to those from the OS using interrupts and a shared memory interface like any other peripheral.

[coreblocks]

On the Zynq family of devices, you can load bitstreams at runtime from Linux through a device file in /dev