Bundled releases link OpenBIOS only; retail-BIOS-derived C never ships.
"Bring your own BIOS" now works without it: when a dump matching a shipped
profile (psx_bios_known_images.h) is selected, the runtime builds that
backend on the player's machine with the overlay toolchain the release
already carries, caches it, and loads it as one more registered backend.
- runtime/include/psx_bios_module.h: the module contract. An overlay-style
self-contained shared library (no imports from the executable) exporting
psx_bios_module_{abi,codegen_hash,init,backend}; reaches the runtime only
through OverlayCallbacks plus a new PsxBiosModuleCallbacks table (traps,
dirty-RAM/kernel-bless probes, fntrace, log_probe) and pointer aliases of
the globals the generated dispatcher touches. Its #defines rewrite the
emitter's own extern lines, so the generated C compiles unchanged.
- runtime/include/psx_bios_module_glue.c.inc: module-side forwarders and the
four exports, compiled after overlay_dispatch_preamble.c.inc.
- runtime/src/psx_bios_module.c: host side. Cache path
<exe>/cache/bios/<os-arch>/bm<abi>_<codegen hash>_f<flavor>/<STEM>_<crc>,
ABI + codegen-hash gated load, callback fill, and a blocking build via
overlay_toolchain/bios_module_build.py (gcc via compiler.txt or PATH,
else tcc), then psx_bios_register().
- psx_bios_backend.c: the registry is now a mutable table seeded from the
CMake-generated psx_bios_builtin_registry by a constructor, with
psx_bios_register(); every existing walker keeps working.
- main.cpp: validate_bios_for_launch acquires a module (announcing a first
build) before declaring a mismatch; discovery accepts a buildable dump;
the launcher verify reports it usable ("ready" / "compiled on first
launch") with no Generate & rebuild; the BIOS row shows whenever the
toolchain is present; bundled_only respects module support.
- emitter: the CPS-marker constructor is not emitted in a module build.
- overlay_api.h: OverlayCallbacks gains a struct tag;
overlay_loader_callbacks() exposes the host table before loader init.
- tools/bios_module_build.py (ships in the toolchain): identity + profile
SHA-256 gate, staged emitter tree, emit, three-TU compile, ctypes
self-check, atomic publish. release_stage.py stages psxrecomp-bios, every
bios/*.toml, the seeds and the builder into overlay_toolchain/.
- Tests: runtime/tests/test_bios_module_host.c against three fake modules
(good / wrong ABI / wrong hash) on real dlopen; recompiler/tests/
test_bios_module_build.py builds the bundled OpenBIOS end to end and reads
the descriptor back; guards extended.
Verified on Twisted Metal 4 (bundled build + staged toolchain, headless):
first launch with --bios SCPH1001.BIN builds and loads the module and boots
on image=SCPH-1001; the second launch loads it from cache.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Matthew Stanley