bbc-c

C compiler for the BBC Micro series of micros

The repository is aranged as such

Folder	Contents
bbcasm	6502 assembler outputting a with a custom object file header
bbcc	the C compiler proper
bbcdisk	utilities for BBC Micro FDD disk images
bbcld	linker for said custom 6502 object files
bbcnix	the begginings of *nix for the Beeb (should probably have it's own repo)
bbcpython	a simple python interpreter for the Beeb (should also be in its own repo)
bbctape	utilities for BBC Micro tape images
bbcvm	a custom 32-bit x86-like virtual machine for the 6502
bbcvmasm	an assembler for the custom VM
bbcvmem	a python GUI emulator implementing the VM's instruction set
bbcvmld	linker for the VM object files
lib	compiled C standard library
lib_src	source of the C standard library
memory-expansion	kicad files for a 24-bit bus memory expansion module for the Beeb

Usage

This project requires python 3.

main.py is the entrypoint for everything.

usage: main.py [-h] [-o OUTPUT] [-Wa [WA [WA ...]]] [-Wl [WL [WL ...]]] [-S]
               [-c] [-shared] [-static] [-strip] [-6502]
               files [files ...]

Compiler suite for the BBC Microcomputer

positional arguments:
  files                 Input files

optional arguments:
  -h, --help            show this help message and exit
  -o OUTPUT, --output OUTPUT
                        Output file name
  -Wa [WA [WA ...]]     Assembler options
  -Wl [WL [WL ...]]     Linker options
  -S                    Compile only
  -c                    Compile and assemble but do not link
  -shared               Create a shared library
  -static               Create a statically linked executable
  -strip                Strip names of internal symbols from executable header
  -6502                 Assemble and link (unable to compile) for 6502 instead of VM

If no output is specified the generated .s .o and out files be put in the current directory. Otherwise the out (output executable) file will be the specified output file, and the .s and .o files will go in the same directory as the output file.

All input files must have the same extension (of the same type). If they are .c then they will be compiled (VM output only) assembled and linked (unless specified otherwise). If they are .s then they will be assembled and linked (unless otherwise specified). If they are .o then they will be linked.

The VM

The VM is documented in greater detail in it's bbcvm/instruction_set.md file. The 6502 implementation of the VM is in the bbcvm/vm.s file.

The bbcvm/loader.s file reads files from the BBC Micro filing system into the memory on the extender module, connected to the system's expansion bus.

There is a python emulator for the VM that reads in files linked with both -static and -shared set. The emulator requires WXPython.

C standard library

The source of the current standard library is in lib_src. Compiled versions are in lib, however if you wish to compile them again the build-lib.sh script exists.