Nexus SAL MAP Internals

Nexus SAL/MAP Bounded Route

DONE

The retail Japanese corpus at FIRESTAFF_NEXUS_DATA_DIR contains sixteen SNDLEV00 through SNDLEV15 SAL/MAP pairs. Each MAP has a 24-byte leading region, a sequence of eight-byte records, and an ffff terminator. The implemented record route retains only the observed fields: raw selector byte, raw attribute byte, big-endian SAL offset, and big-endian SAL size. It accepts a selector only when it occurs exactly once and its complete SAL window is in bounds. The focused corpus test covers all sixteen pairs.

The SAL side now also decodes the DMWeb DataID 0 tone-bank directory from the real SAL stream: its big-endian entry-offset table, four variable entries, the later 4 + 32*n entries, PCM width bit, source-control bit, and bounded sample payload metadata. This is still not an audio route: the MAP selector and attribute have no asserted Saturn event meaning, and no playback is requested from this result.

Host-Side Event Dispatch (Still Unmapped)

nexus_sound_set_event_selector() lets the host engine bind a Nexus_SoundEvent to a raw MAP selector, and a per-event dispatch table (g_event_selector, default -1/unmapped) looks up the bound selector at playback time. This is purely a host-owned binding mechanism — it does not assign Saturn event meaning to any selector value. Until original Saturn event→selector evidence is available, every entry stays unmapped and the dispatch table is fail-closed.

TODO

Establish the Saturn sound-driver call ABI and event→selector mapping from executable trace or disassembly evidence. Only that evidence can assign selector meaning, interpret the attribute byte, or permit audio playback.

Verification

cc -std=c99 -Wall -Wextra -O2 -Iinclude \
  tests/test_nexus_v1_sal_map_corpus.c \
  src/nexus/nexus_v1_sound.c src/nexus/nexus_v1_audio_receipt.c \
  -o /tmp/test_nexus_v1_sal_map_corpus
FIRESTAFF_NEXUS_DATA_DIR=/Users/bosse/.firestaff/data/nexus \
  /tmp/test_nexus_v1_sal_map_corpus