shecc VS selfie

Yes, consider the case of shecc. It requires just a handful of C code lines to interpret directives set in the C preprocessor. Unlike relying on existing tools like cpp, as, or ld, shecc stands alone as a minimalist cross-compiler. This design could be particularly beneficial for students delving into the study of compiler construction. See https://github.com/sysprog21/shecc/blob/master/src/lexer.c#L...

I'm looking at this one for a CPU design I've been working on. :)

https://github.com/jserv/shecc

this sort of exists at https://github.com/cksystemsteaching/selfie

> Selfie is a self-contained 64-bit, 12KLOC C implementation of: (...) a tiny (...) subset of C called C Star (C) (...) to a tiny (...) subset of RISC-V called RISC-U[;] a[n] (...) emulator (...) that executes RISC-U code[;] (...) a (...) hypervisor (...) that provides RISC-U virtual machines*

so they have an instruction set architecture, a compiler, and an operating system, though it's much simpler than xv6. because the instruction set is a subset of risc-v you can run its code on actual risc-v hardware (or qemu-system-riscv), but presumably you could also design risc-u hardware in verilog that was simpler than a full implementation of rv64i with whatever extensions the hypervisor needs