Files
psxrecomp/docs/beetle-linux.md
T
Claude 99a4002ffb oracle: CD-command trace hook + live-diff localizes Kula World bug 3
Adds a CD-command trace to psx-beetle (beetle_cdcmd_trace_hook.patch:
callback in cdc.cpp's command dispatch, wired through beetle_libretro.cpp
into cdrom_cmd_dump / cdrom_cmd_reset on the oracle debug server). This is
the two-process oracle-diff the setup is built for, now working on Linux.

Live-diff result (docs/kula-world-findings.md, bug 3): the oracle's game
reads level data with a clean Setloc->SeekL->Setmode->ReadN->Pause per
sector (SeekL x18, ReadN x22, GetlocL x89). Our runtime's game, in the
wedge, issues NEITHER SeekL NOR ReadN — only GetStat/Init/Setloc/Pause,
an error/retry branch the oracle never enters.

Crucial: our runtime DID deliver 307 sectors during early boot (ReadN +
data delivery work). Reads only stop at frame ~890 — the BIOS mid-game
region revalidation (ReadTOC+GetID). The region fix made that PASS, but
the post-ReadTOC CD state still stops the game resuming reads. Prime
suspect: our ReadTOC (case 0x1E) is a bare stat+COMPLETE stub that does
not model drive repositioning / the track table the game reads to
recompute its seek. Documented for the next session.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BdjxoRB1f9VQsNzZayCgGS
2026-07-02 19:05:47 +00:00

1.9 KiB

Building psx-beetle on Linux

The psx-beetle oracle builds and runs on Linux with the same wire protocol as on Windows. Verified 2026-07-02 (Kula World boots to demo gameplay; ping/screenshot served over the TCP debug protocol).

beetle-psx checkout

runtime/src/beetle_libretro.cpp targets the C++ beetle-psx tree. Upstream master has since been converted to plain C (libretro.cpp -> libretro.c, PS_CPU class dropped), which no longer compiles against our integration. Pin the checkout to the last compatible commit — the same base docs/beetle_wtrace_hook.patch was generated from:

git clone https://github.com/libretro/beetle-psx-libretro.git beetle-psx
cd beetle-psx
git checkout 5759277b          # "audit pass" — last C++-tree base we target
patch -p1 < ../docs/beetle_wtrace_hook.patch
patch -p1 < ../docs/beetle_sio_trace_hook.patch
patch -p1 < ../docs/beetle_cdcmd_trace_hook.patch

beetle_cdcmd_trace_hook.patch adds a CD-command trace callback (fires per command dispatch in cdc.cpp) exposed as the cdrom_cmd_dump / cdrom_cmd_reset debug commands — used to oracle-diff the Kula World CD read sequence.

beetle_sio_trace_hook.patch adds FrontIO::SetSIOTraceCallback (fires per completed SIO byte exchange) — an integration hook beetle_libretro.cpp needs that predated the committed wtrace patch.

Build

# Static lib. On unix the artifact is named mednafen_psx_libretro.so but is
# an ar archive (STATIC_LINKING=1); stage it under the name cmake expects.
make platform=unix STATIC_LINKING=1 HAVE_LIGHTREC=0 -j"$(nproc)"
cp mednafen_psx_libretro.so libmednafen_psx.a

cd ../runtime
cmake -B build -G Ninja -DCMAKE_BUILD_TYPE=Release -DPSX_LAUNCHER=OFF -DPSX_DEBUG_TOOLS=ON
ninja -C build psx-beetle

# Headless run (picks the next free port from 4380 if taken; watch stderr)
xvfb-run -a ./runtime/build/psx-beetle ../bios/SCPH1001.BIN --disc <game.cue>