llvm-mos SDK

Introduction

This is a project to develop a software development kit for practical MOS 6502-compatible computers. It contains CMake source scripts, source files, and linker files to demonstrate using the llvm-mos compiler to generate ready-to-run executables for several popular 6502 targets.

To see the current list of supported targets, check out the LLVM_MOS_PLATFORMS variable in cmake/Constants.cmake .

Requirements

You'll need CMake 3.10 or later.

You'll also need the llvm-mos compiler suite properly built and installed for your machine.

You can download a precompiled llvm-mos toolchain, if you want to save time. Alternatively, security-minded folks may prefer to roll their own llvm-mos compiler from source.

If you decide to build this toolchain locally, use the cmake/LLVM-cache.cmake file to prime the CMake cache, in order to build a compatible llvm-mos toolchain:

git clone https://github.com/llvm-mos/llvm-mos
cd llvm-mos
mkdir build
cd build
cmake ../llvm \
      -C /path/to/llvm-mos/LLVM-cache.cmake \
      -DCMAKE_INSTALL_PREFIX=./install \
      -DCMAKE_BUILD_TYPE=Release
cmake --build . --target distribution

Installation

To use the SDK, use CMake in a build directory to configure your project. From the root of this SDK:

mkdir build
cd build
cmake .. 
cmake --build .

The CMake configure step will attempt to find a working llvm-mos installation along the path. You can provide a hint to CMake where to find the llvm-mos executables:

cmake .. -D_CMAKE_TOOLCHAIN_PREFIX=/path/to/llvm-mos/build/install/bin

Directory structure

The cmake subdirectory contains CMake scripts for finding a compatible compiler and assembler combination, and configuring it to compile the contents of this SDK.

The src/common directory contains linker scripts and includable source files that are common across multiple targets.

The src/example directory contains example programs which can be compiled and run on multiple targets.

The src/platform directory contains per-platform linker scripts and source code.

CMake configuration settings

Name	Type	Description
`LLVM_MOS_GENERATE_LINK_REPORTS`	Boolean	Generate lots of debug information when compiling an executable, including the output of llvm-readelf, llvm-objdump, and llvm-dwarfdump.
`LLVM_MOS_PLATFORMS`	List	The list of 65xx platforms to be targeted in a build. These platforms should have the same names as their MAME equivalents.

See also the CMake constants in cmake/Constants.cmake, which you may override if necessary.

johnwbyrd / llvm-mos-sdk