Cockatrice III — 64-bit Port

This branch ports Cockatrice III (a BasiliskII derivative) from 32-bit-only builds to native 64-bit builds on macOS (Apple Silicon and Intel) and Windows (x64 and ARM64), while keeping the existing 32-bit Windows build working.

The historical release notes live in README / README.old. This file only covers what changed to make 64-bit builds possible.

Why this was needed

BasiliskII's 68k CPU emulator (UAE) and memory subsystem were written with the assumption that a host pointer fits in 32 bits. Several places in the codebase either truncated a pointer into a 32-bit UAE register or typedef'd uintptr to a fixed 32-bit integer. On a 64-bit host that truncation silently drops the top 32 bits of a real pointer, which reliably crashes or corrupts memory as soon as the emulator touches Mac RAM/ROM above the low 4GB of address space (or, in practice, whenever the host allocator hands back a 64-bit address, which it always does).

Key changes

• uintptr is now a real pointer-sized integer. BasiliskII/mingw/sysdeps.h previously hardcoded typedef unsigned int uintptr; (32-bit, always). It now uses typedef uintptr_t uintptr; from <stdint.h>. The new BasiliskII/OSX64/sysdeps.h does the same. This is what uae_cpu/memory.cpp relies on for RAMBaseDiff/ROMBaseDiff/ FrameBaseDiff to correctly round-trip a host pointer.

• Ethernet packet delivery no longer truncates a host pointer into a 32-bit UAE register. BasiliskII/SDL/sdl_pcap.cpp used to pass the host packet buffer address as r.a[0] = (uint32)p + 14, which loses the high bits of the pointer on 64-bit hosts. It now stashes the pointer out-of-band via EtherSetPacketData() and clears r.a[0]; the new ether_packet_data side channel in BasiliskII/ether.cpp (declared in BasiliskII/include/ether.h) is what EtherReadPacket() reads from instead of trusting the 32-bit register. BasiliskII/emul_op.cpp was updated to match the new EtherReadPacket calling convention.

• Unaligned memory access helpers use compiler builtins instead of hand-rolled bit tricks. do_get_mem_long/do_put_mem_long/etc. in sysdeps.h (mingw and OSX64) now use __builtin_bswap32/__builtin_bswap16 and are enabled for __x86_64__, __aarch64__, _M_X64, and _M_ARM64, in addition to the original __i386__/__powerpc__/__m68k__ set.

• Fixed a real logic bug in 64-bit disk positioning. BasiliskII/disk.cpp combined the high and low 32 bits of a 64-bit disk offset with || (logical OR) instead of | (bitwise OR), which is only correct by accident when the low bits happen to be non-zero. This is unrelated to the host architecture but was caught while auditing the 64-bit code paths.

• Removed other latent 32-bit assumptions:

  • BasiliskII/SDL/video_sdl.cpp: SDLscreen->pixels is a void*; pointer arithmetic on it now casts to uint8* first (this silently "worked" via GCC's non-standard void* arithmetic extension, but fails to compile with a strict/newer Clang toolchain).
  • BasiliskII/dummy/audio_dummy.cpp: audio_sample_rates changed from uint32 to int32 to match the signature expected elsewhere.
  • BasiliskII/dummy/user_strings_dummy.cpp and BasiliskII/dummy/cdrom_dummy.cpp: const-correctness and bool/FALSE cleanups needed by modern C++ compilers (Clang/GCC 8+) that reject the old code as ill-formed or warn it into a build failure under -Werror-adjacent settings.
  • BasiliskII/SDL/main_sdl.cpp: Windows header includes changed from backslash (SDL\SDL.h) to forward-slash (SDL/SDL.h) paths, since MSYS2/MinGW toolchains don't treat \ as a path separator in #include. DrMinGW crash-handler integration (exchndl.h, ExcHndlInit()) is now gated to 32-bit x86 (or an explicit USE_EXCHNDL define) since DrMinGW doesn't support x64/ARM64.
  • BasiliskII/mingw/config.h: SIZEOF_VOID_P / SIZEOF_CHAR_P are now computed correctly (8 on _WIN64/__x86_64__/ __aarch64__, 4 otherwise) instead of being hardcoded for 32-bit.

Directory / build layout changes

• BasiliskII/OSXarm (the initial Apple Silicon-only port) was renamed to BasiliskII/OSX64 and its Makefile now builds either Apple Silicon or Intel Macs from one tree via an ARCH variable (arm64 by default, or x86_64/ amd64), selecting the right Homebrew SDL prefix (/opt/homebrew vs /usr/local) and -arch flag automatically. make universal in that directory builds both slices and lipos them into a fat CockatriceIII (needs both Homebrew prefixes).
• BasiliskII/mingw/Makefile was rewritten to build Windows x86, x64, or ARM64 from the same tree using whatever MSYS2 toolchain/MSYSTEM (MINGW32/MINGW64/CLANGARM64) invokes it, using sdl-config when available instead of hardcoded library paths.

CI: GitHub Actions

.github/workflows/build-and-release.yml builds all six targets on every push, on pull requests into main, and on v* tags (which also cuts a GitHub Release):

Target	Runner	Build dir
osx-arm	macos-latest (native arm64)	BasiliskII/OSX64
osx-amd64	macos-latest (cross x86_64)	BasiliskII/OSX64
osx-universal	macos-latest (lipo fat)	BasiliskII/OSX64
win32-x64	windows-latest (MINGW64)	BasiliskII/mingw
win32-x86	windows-latest (MINGW32)	BasiliskII/mingw
win32-arm	windows-latest (CLANGARM64)	BasiliskII/mingw

Each job packages its build (.dmg on macOS, .zip on Windows) alongside the files in dist/ and uploads it as a build artifact; on a version tag the artifacts from all targets are attached to a single GitHub Release.

The workflow triggers on push to any branch (not just main), so pushing a feature/port branch like osx-arm runs the full build matrix without needing to merge first.