riscv-isa-sim VS nanoCH32V305

Someone correct me if I'm wrong, but Spike is considered the gold standard for RISV-V simulation, in terms of support for extensions and overall correctness. As I understand it, QEMU is faster and easier to use for day-to-day for general software development.

Spike is an RISC-V instruction set simulator: https://github.com/riscv-software-src/riscv-isa-sim

I really like the source code for the Spike RISC-V ISA Simulator. It's not very heavily commented, though, so you really need to read the code.

If you want to run bare metal with no RTOS, it should be possible, but you will need to replace the main startup program (https://github.com/riscv-software-src/riscv-isa-sim/blob/master/spike_main/spike.cc) with some program to set up the hardware and instantiate the simulator, load the OS image etc and then have a decent runtime environment to that supports malloc() etc and redirect IO to serial or flash memory etc. There is a bit of work you would need to do.

I guess you will also use Spike and the Sail model for RISC-V.

If you are willing to try r/RISCV ones, then nanoCH32V203 (with two Full-Speed interfaces) and nanoCH32V305 (with one Full-Speed and one High-Speed interface) might be enough.

There are dual USB r/RISCV boards with GPIO pins exposed, like nanoCH32V203 and nanoCH32V305.

There are RISC-V MCUs that have two USB interfaces, but those are not supported by QMK yet. I tried some of those boards in kite project.

Kite has standard shortcuts option too, but it runs on dedicated MCU board, not host PC.

RISC-V boards cost $3-$6 depending if you want high speed USB or full speed one.

u/Bounty1Berry is exploring RISC-V nanoCH32V305 board, but it's a new board that is not supported by (Q|T|Z)MK yet, so not really go-to option at this stage.

Their earlier boards like nanoCH32V203 and nanoCH32V305 were more user friendly, one could flash those via USB without WCH-Link.

Muse Lab has MCU boards like nanoCH32V203 and nanoCH32V305.

It runs on nanoCH32V305 dual USB r/RISCV MCU board.