libriscv VS vemips

Seeking: https://github.com/fwsGonzo/libriscv

This is a C++ RISC-V emulator that focuses on isolating a single process, aka userspace emulation. I am currently working mostly on binary translation, and recently I have made a push to move it from experimental state to fully supported. Another experimental feature is embedding libtcc and using that for binary translation. It is fairly fast to compile, and gives decent speedups. The challenge is what to do now that (perhaps) some low hanging fruits have been picked.

I definitely recommend people to consider the base ISA of RISC-V if they want to try to implement a CPU or even full-system emulation. I understand that implementing a GameBoy emulator might be more attractive because you are working towards something graphical, but you can definitely get something similar with RISC-V, eg. Doom (SDL example: https://github.com/fwsGonzo/libriscv/tree/master/examples/do...)

This is the example project: https://github.com/fwsGonzo/libriscv/tree/master/examples/msvc

Pretty much two days of work: https://github.com/fwsGonzo/libriscv/commits/master

Show HN: Libriscv – RISC-V userspace emulator library\ (7 comments)

There is a doom emulation demo here now: https://github.com/fwsGonzo/libriscv/tree/master/emulator/do...

You will need to add the shareware doom1.wad yourself. :)

Also, if anyone wants to see a hastily-written ELF loader that I haven't cared enough about to go back and clean up in C++, I have one here.

I suggest MIPS.

I actually wrote VeMIPS for this specific purpose.

Unfortunately, I don't remember specifically. It was about when I wrote VeMIPS and was also working on figuring out an alternative ISA for a 3d printer board, and I'd noticed that a specific conversion instruction was missing on it. Maybe it was moving a double-precision register to the general purpose registers on 32-bit? Not sure anymore. I can look over IRC logs maybe to find out.

This is the exact purpose that I wrote VeMIPS for.

Looks similar to vemips. Same rationale as well (embedding within a game or simulation).

Probably wouldn't be too hard to add Chip8 as a backend to VeMIPS, though VeMIPS presently doesn't run on Android (only Win64 and in Javascript using asm.js).

I personally dislike disassembling MIPS, and I wrote VeMIPS!

However, I did end up releasing VeMIPS, which is an embeddable MIPS32r6 emulator/VM which is heavily configurable, has a dynamic recompiler, and has instruction-level execution granularity, meaning that you can tell it "execute 10 instructions and return". This lets you implement things like cost per instruction, virtual CPUs with different performance characteristics, and so forth.