RISC-V GCC Bare-Metal Crosscompiler

This repository provides automated builds of a complete RISC-V bare-metal crosscompiler toolchain, including:

• binutils: Assembler, linker, and binary utilities
• GCC: C and C++ compiler
• newlib: Embedded C library

Features

• Portable: Built using manylinux containers for maximum Linux compatibility
• Self-contained: All necessary libraries included with proper RPATH configuration
• Multi-architecture: Supports x86_64 and ARM64 (aarch64) Linux systems
• Automated: Weekly builds with the latest stable versions
• Bare-metal: Configured for embedded systems without OS dependencies

Target Configuration

• Target triple: riscv64-unknown-elf
• Default architecture: rv64imac
• Default ABI: lp64
• Multilib variants: Custom configuration with 4 optimized targets:
  • rv32i/ilp32 - RV32 base integer instruction set
  • rv32imac/ilp32 - RV32 with integer multiply, atomics, compressed
  • rv64i/lp64 - RV64 base integer instruction set
  • rv64imac/lp64 - RV64 with integer multiply, atomics, compressed (default)

Installation

1. Download the appropriate tarball for your system from the Releases page
2. Extract: tar xzf gcc-riscv-*.tar.gz
3. Add to PATH: export PATH=$PWD/gcc-riscv/bin:$PATH

Usage

# Compile with default (rv64imac/lp64)
riscv64-unknown-elf-gcc -o program.elf program.c

# Compile for RV32 base integer
riscv64-unknown-elf-gcc -march=rv32i -mabi=ilp32 -o program.elf program.c

# Compile for RV32 with multiply, atomics, compressed
riscv64-unknown-elf-gcc -march=rv32imac -mabi=ilp32 -o program.elf program.c

# Compile for RV64 base integer
riscv64-unknown-elf-gcc -march=rv64i -mabi=lp64 -o program.elf program.c

# Compile with default (rv64imac)
riscv64-unknown-elf-gcc -march=rv64imac -mabi=lp64 -o program.elf program.c

# Check available multilib variants
riscv64-unknown-elf-gcc -print-multi-lib

Build Process

The build process:

1. Builds binutils for RISC-V target
2. Builds GCC stage 1 (without C library)
3. Builds newlib C library
4. Builds GCC stage 2 (complete with C/C++ support)
5. Strips binaries and fixes RPATH for portability
6. Creates portable tarball

Portability Features

• Uses patchelf to set $ORIGIN-relative RPATHs
• Detects and reports binaries with hardcoded paths
• Verifies all dependencies are satisfied
• Tests compilation after build

CI/CD

Automated builds run:

• On every push
• Weekly (Sundays at 12:00 UTC)
• On manual trigger

Builds are created for:

• manylinux2014_x86_64 (GLIBC 2.17+)
• manylinux_2_28_x86_64 (GLIBC 2.28+)
• manylinux_2_28_aarch64 (ARM64, GLIBC 2.28+)

License

This is a binary distribution. Please refer to the licenses of the individual components:

• GCC: GPL-3.0
• binutils: GPL-3.0
• newlib: Various (BSD-like licenses)