flybrain/services/flysim/vendor/binjgb/PROVENANCE.md

binjgb (vendored)

• Upstream: https://github.com/binji/binjgb
• Revision: c60e138da5a795ebb55e56b11b7e90024e41112c
• License: MIT, see LICENSE.
• Copied from the fly-plays-pokemon prototype's checkout of that revision (.tools/binjgb), which is the same revision pinned in the prototype's compatibility string.

What is here

Only the sources the binjgb emulator core needs. CMakeLists.txt at that revision builds the Emscripten target from

src/memory.c src/common.c src/emulator.c src/joypad.c src/rewind.c
src/emscripten/wrapper.c

Of those, joypad.c and rewind.c are needed only by wrapper.c's rewind and joypad-replay features; emulator.c itself references neither. flybrain-gb does not use rewind, so the vendored set is:

src/emulator.c  src/emulator.h
src/common.c    src/common.h
src/memory.c    src/memory.h
src/builtin-palettes.def   (#include'd by emulator.c)

Nothing here is modified from upstream. No host, SDL, OpenGL, ImGui, debugger, tester, options or Emscripten source is vendored.

What replaces src/emscripten/wrapper.c

crates/flybrain-gb/csrc/shim.c in this repository. It mirrors only the wrapper functions the prototype's src/emulator/binjgb.ts actually called, with no Emscripten dependency, no static emulator singleton, and no rewind or joypad buffer. The prototype's wrapper was itself locally patched to apply joypad state directly rather than through an accumulating rewind buffer; the shim does the same by calling emulator_set_joypad_buttons and installing no joypad callback.

emulator_read_mem and emulator_get_wram_ptr are defined in emulator.c but declared in no header at this revision: the Emscripten build reached them through its export list and an implicit declaration. The shim declares them itself so it compiles warning-clean.

Build defines

None. CMakeLists.txt declares RGBDS_LIVE and GBSTUDIO as options that default to OFF, and the js/wasm Makefile targets that produced the prototype's binjgb.js pass neither. The build therefore compiles the same configuration the prototype ran, which means:

• emulator_set_breakpoint, emulator_clear_breakpoints, emulator_get_banked_PC and emulator_render_vram are not compiled in;
• EMULATOR_EVENT_BREAKPOINT can never be raised. Emulator::run_frame still checks for it, as the prototype did.

build.rs defines no NDEBUG of its own. The cc crate defines it for profiles with debug assertions off, so assert(buffer->position <= buffer->end) in write_audio_frame stays live in debug builds, where a misconfigured audio_frames would otherwise corrupt memory quietly. -fno-strict-aliasing is set for binjgb's type-punning paths. -Wno-unused-parameter, -Wno-unused-function, -Wno-unused-variable and -Wno-implicit-fallthrough mirror the warning flags CMakeLists.txt sets for non-MSVC compilers.