I work on a custom board with a Cyclone V SoC FPGA. I have created preloader & (u-boot) bootloader successfully. I have generated a linux 4.15.7 kernel with Buildroot and it also loads without problem. I can access the FPGA matrix with my custom drivers and so on…
All parts are loaded at boot time by the u-boot startup script.
Now I want to load the FPGA from my linux userland. I’ve read several threads on rocketboard, SO, etc… I understand that the first solution was to copy the RBF file onto /dev/fpga0 but this is not yet supported. (https://rocketboards.org/foswiki/Documentation/GSRD131ProgrammingFPGA)
The new solution is to use Device tree Overlay (How to program FPGA from HPS (de10-nano)).
But Device-tree overlay is not yet supported in recent linux kernel. My question is : What’s is the recommended method to load the FPGA matrix from linux ?