DOOM port for PolkaVM

This is a DOOM port for PolkaVM.

It's based on doomgeneric, but it's even more portable. The source code is completely standalone and doesn't even require a libc. It also has out-of-box support for audio due to built-in OPL emulation, which doomgeneric doesn't have.

Building

1. Get a clang for RV{32,64}E (RISC-V embedded)
   • Upstream LLVM from version 18.X and above support those
   • Scripts to build a toolchain are available here or here
2. Make sure that the compatible LLVM build is found via $PATH. Verify: clang --target=riscv32 -print-supported-extensions 2>&1 | grep 'RV{32,64}E'
3. Run ./build.sh 32 or ./build.sh 64 to get a 32bit or 64bit build respectively
4. Run polkatool link -s output/doom.elf -o output/doom.polkavm.

License

GPLv2+

Many third-party libraries are used here with varying licenses; see the libs directory for details.