riscv-asm-manual VS riscv-gnu-toolchain

This document has most of the explanations about the input format: https://github.com/riscv-non-isa/riscv-asm-manual/blob/master/riscv-asm.md. There are some small missing bits but all the directives like .text are there.

The is a C and C++ toolchain available https://github.com/riscv-collab/riscv-gnu-toolchain If you feeling brave, https://github.com/riscv-non-isa/riscv-asm-manual/blob/master/riscv-asm.md

> Note: "jalr zero, 1b" can also be written as "j 1b", "jalr zero, 0(ra)" can be written as "ret"

`j` and `ret` are so-called "pseudo instructions" [1], not compressed instructions.

Pseudo instructions are just shortcuts used in assembly language to pretend that some common operations really "exist" with the need to type (or display) the real, more complex instructions. `nop` is a common pseudo instruction. RISC-V has `nop` instructions, but, instead, the "do nothing instruction" is canonically encoded as `addi x0, x0, 0`.

The compressed instruction set (a.k.a "extension C") is a subset of the full [2] instruction set, in which a restricted combinations of operands are possible. The assembly (human readable) code of the compressed instruction set looks similar to that of the full instruction set (including pseudo instructions), but they are encoded as completely different binary sequences.

[1] https://github.com/riscv/riscv-asm-manual/blob/master/riscv-...

[2] https://riscv.org/wp-content/uploads/2019/06/riscv-spec.pdf#...

This should be helpful https://github.com/riscv/riscv-asm-manual/blob/master/riscv-asm.md

> no absurdely and grotesquely massive and complex compilers anywhere

Absence of evidence is not evidence of absence, and anyway there's not even an absence: https://github.com/riscv-collab/riscv-gnu-toolchain https://llvm.org/docs/RISCVUsage.html

> feature creeps on computer language syntax nowhere to be found

At least one of us is very confused, and in case it's me, how do language details matter to RISC-V?

I then looked at the .cargo/config.toml provided by the guide and saw that it wasn't actually statically compiling the code. After a bit of tinkering and building my own toolchain from here, I ended up with this config.toml file:

b) collabriscv - essentially gcc 12.2 + binutils master/2.40 as per https://github.com/riscv-collab/riscv-gnu-toolchain

Or would it be better to take what is in https://github.com/riscv-collab/riscv-gnu-toolchain which is gcc 12.2 and start from there?

I'm not able to build https://github.com/riscv-collab/riscv-gnu-toolchain.git like this: