It all depends on your definition of "open", of course. As far as I know there is no open-source toolchain for any remotely-recent FPGA, so you're still stick with proprietary (paid?) tooling to actually modify it. You're pretty much out of luck if you need more than an iCE40 UP5k.
There's been some interesting recent work to get the QMTech Kintex7-325 board (among others) supported under yosys/nextpnr - https://github.com/openXC7
It works well enough now to build a RISC-V SoC capable of running Linux.
