Missing macOS installation instructions in README after setup steps

[DePoli97]

Hello,

I noticed that the README includes commands for macOS to install dependencies via Homebrew (for example, brew install autoconf automake ...), which suggests that macOS is partially supported.

However, after following these steps, there are no further instructions or examples showing how to actually build or install the toolchain on macOS. The Linux instructions use make build-rv32imc, but that target doesn’t exist when building on macOS — and no equivalent steps are provided.

[FrancescoConti]

You are confusing the target (pulp/newlib/linux) with the host (macOS/some linux distribution). Assuming you want to install GCC7 with xpulpv2 extensions, you have to follow the instructions here: https://github.com/pulp-platform/pulp-riscv-gnu-toolchain?tab=readme-ov-file#installation-pulp

There is no need for separate macOS- vs Linux-dedicated instructions as both macOS and Linux are Unix-based OSes, the same instructions will work in both of them. I have never built for the linux target from this source, that comes directly from the toolchain from which this one was forked a very long time ago (https://github.com/riscv-collab/riscv-gnu-toolchain) and might be broken. But the pulp target should work fine on macOS, I built it no problem a while ago.

OTOH, it might be more difficult to make other PULP-related frameworks work under macOS (particularly GVSOC, at least it used to be so some time ago). If you encounter challenges, my suggestion is to work in a Linux VM or Docker, which should significantly simplify your life.

[DePoli97]

Hi @FrancescoConti

Indeed PULP target should build on macOS, but in practice the process fails when running the same commands provided in the official documentation, e.g.:

./configure --prefix=/opt/riscv --with-arch=rv32imc --with-cmodel=medlow --enable-multilib
make

On macOS (tested on Tahoe, Apple Clang), this sequence consistently breaks due to a few BSD vs GNU differences:

• readline module — Fails with identifier 'ECHOCTL' is undefined and missing ioctl declarations.
• gcc/cp/enum-flags.h — Template and underlying_type handling differed on Apple Clang (C++11 vs GNU G++), causing compilation errors.
• gcc/config/riscv/riscv.h — Some host-specific logic implicitly assumed a GNU host; added a guarded define for APPLE to make host-dependent behavior explicit.

All the fixes are behind #ifdef APPLE guards, so Linux builds are completely unaffected.
After applying these patches, the toolchain builds cleanly end-to-end on macOS using the same configure/make steps as Linux.

I’ve opened pull requests for the affected submodules and the top-level toolchain:
• pulp-riscv-binutils-gdb
• pulp-riscv-gcc
• pulp-riscv-newlib
• pulp-riscv-gnu-toolchain

These collectively fix the macOS build without impacting existing Linux users.

Thanks you; hopefully this contribution makes macOS support officially consistent with the documentation!