psxrecomp/docs/config_schema.md

PSXRecomp v4 — config TOML schema

Consumed by:

• psxrecomp-bios.exe and psxrecomp-game.exe (via --config <toml>)
• tools/audit_config.py and the audit tooling that wraps it
• The runtime cmake macro (runtime/runtime.cmake)

Examples:

• bios/SCPH1001.toml — BIOS-only config (no game; psx-runtime targets this)
• ../TombaRecomp/game.toml — game config (tomba-runtime targets this)

How configs combine

A PSXRecomp v4 process always has a BIOS config. It optionally also has a game config. Both are TOML files in this schema:

• bios/SCPH1001.toml (or another BIOS .toml in bios/) — describes the BIOS. Always loaded.
• <game>/game.toml — describes a single game. Loaded ONLY when running that game.

psxrecomp                            # BIOS-only regen (uses default bios.toml)
psxrecomp games/tomba/game.toml      # BIOS + game regen
psx-runtime                          # boots BIOS discless
psx-runtime games/tomba/game.toml    # boots BIOS, then loads game

When both are loaded, keys merge:

• Scalar keys (debug_port, window_title, memcard_dir, ...): game wins if set, inherit from bios.toml otherwise. Shallow override.
• [program] (BIOS) and [game] blocks: NOT merged — they describe different programs. Both are visible to the loader.
• Generated dispatch tables and C output: ADDITIVE. BIOS contributes SCPH1001_*.c; game contributes <exe>_*.c. No address overlap is expected (BIOS lives at RAM 0x500-0x8500 + ROM 0xBFC..., game at 0x80010000+). The cmake macro psxrecomp_v4_add_runtime_target already links both.
• [[audit.regions]] and [[audit.normalize.remap]]: additive — game adds its regions on top of BIOS's.

Top-level blocks

[program]    # in bios.toml; describes the BIOS
[game]       # in game.toml; describes the game
[recompiler]
[runtime]
[audit]

Program / game block

• bios.toml has a [program] block describing the BIOS ROM.
• game.toml has a [game] block describing the game EXE / disc.

These are NOT alternatives; they're complementary. A runtime loading both sees both blocks. The legacy single-file audit loader (tools/audit_config.py) accepts either as the program-info source for backwards compat, but going forward they are the canonical names for their respective files.

Fields

Field	Required for	Description
name	both	display name, e.g. "SCPH1001 BIOS"
id	both	canonical id, e.g. "SCPH-1001" or "SCUS-94236"
rom	bios	path to raw flat binary, relative to project root
exe	game	path to PS-X EXE file, relative to project root
load_address	both	hex string, virtual address of first byte ("0xBFC00000" BIOS, "0x80010000" typical game)
entry_pc	both	hex string, first PC to execute
text_size	both	hex string, size in bytes of the static region. For games this also bounds main-EXE analysis and establishes the overlay floor. A smaller-than-header bound must be verified non-code and 4 KiB aligned.
stack_base	game	hex string, initial $sp value for the game
disc	game (single-disc)	path to .cue, relative to project root
discs	game (multi-disc)	array of .cue paths; disc is sugar for discs = [disc]

Recompiler block

[recompiler]
seeds       = "recompiler/seeds/phase2_ghidra_seeds.json"  # BIOS
seeds       = "seeds/ghidra_funcs.txt"                     # game (note: game seeds aren't json today)
bios_thunks = "seeds/tomba_bios_thunks.txt"                # game-only
bios_config = "psxrecomp/bios/SCPH1001.toml"               # game-only: BIOS profile whose address
                                                           # model game codegen folds RAM aliases
                                                           # through (see "BIOS profiles" below);
                                                           # defaults to the SCPH1001 profile
out_dir     = "generated"                                  # both
strict      = true                                         # both — currently always true
discovery   = "whole-image"                                # game-only: "whole-image" or "reachable"
out_stem    = "SCPH1001"                                   # optional; overrides the auto-derived stem

[[recompiler.patch]]
id          = "descriptive-policy-name"
address     = "0x80012340"
expected    = "0x24020002"
replacement = "0x24020001"
note        = "Why this game-owned instruction change is required" # optional

Output filenames: <out_dir>/<out_stem>_full.c and <out_dir>/<out_stem>_dispatch.c. If out_stem is omitted, it's derived from the rom/exe file basename with the trailing .BIN or .EXE stripped (Path.stem is NOT used because it mishandles SCUS_942.36).

Game discovery defaults to "whole-image", preserving the existing sweep and pointer-table heuristics. Opt-in "reachable" starts at the executable entry and evidence-backed seed roots, then follows callable direct jal targets. It does not sweep arbitrary bytes for prologues or return-shaped words. Unresolved jalr/indirect targets and unseen callbacks fail closed to runtime interpretation; add an evidence-backed seed (or a dispatch_root seed for a proven nonstandard boundary) when they should be compiled.

When game.text_size is smaller than the PS-X EXE header size, recompilation uses it as a static-analysis bound. The value must be nonzero, instruction- and 4 KiB-aligned, retain entry_pc, and not extend past PS1 RAM. The original EXE is still loaded from the user's disc. A generated config's canonical final-page reservation may be slightly larger than the header; it does not widen analysis.

Each [[recompiler.patch]] replaces one exact 32-bit MIPS word before function discovery, control-flow analysis, and normal translation. It is intended for small, understood game-code changes whose addresses, opcodes, and policy remain in the game repository. The framework does not contain title IDs or title-specific addresses.

• id, address, expected, and replacement are required hex/string fields; note is optional.
• IDs are case-sensitive and unique within one config.
• Addresses must be four-byte aligned and are unique by the PSX 29-bit physical address. Thus 0x00012340, 0x80012340, and 0xA0012340 are aliases of one site and cannot define separate patches.
• Main-EXE generation fails if the word at the target site is not expected. This catches a wrong disc revision or stale patch instead of guessing.
• Captured overlays may place unrelated variants at one virtual address. In overlay mode, a patch is applied only to a variant whose word is expected; a nonmatching variant is translated unchanged.
• When --config and --ws-config supply the same byte-identical patch it is deduplicated. Reusing an ID or physical address for different patch data is an error.

Patches are build-time inputs, not runtime memory writes or live toggles. Regenerate the affected main executable or captured overlays after changing them.

Runtime block

Consumed by the cmake macro psxrecomp_v4_add_runtime_target (eventually) and by runtime/src/main.cpp as the source of compiled-in defaults.

[runtime]
debug_port    = 4370            # TCP port for the debug server
window_title  = "..."           # SDL window title
controller    = "digital"       # "digital" or "dualshock"
memcard_dir   = "."             # memcard files location, relative to project root

Opt-in warm CD routes

Per-game read acceleration is disabled unless the game explicitly declares one or more strict routes. Each route arms on one SetLoc, then requires every later file start to match lbas in order. A mismatch immediately restores the normal configured disc timing. Only data-read cadence is accelerated; XA/CDDA, seek, and motor timing remain authentic.

[[runtime.warm_cd_routes]]
arm_lba = 95947
lbas = [298, 299, 306]
instant_max_per_frame = 32

Up to 16 routes may be declared, with 1–64 LBAs each. The old singular [runtime.warm_cd_route] table is deprecated and emits a warning when loaded; it remains readable for compatibility. This enhancement is intentionally opt-in and must not acquire a global default.

The other load-time accelerators are likewise opt-in:

[runtime]
turbo_loads = true
idle_skip = true
turbo_audio_sink = true

turbo_audio_sink is meaningful only while turbo_loads is active. It keeps the guest SPU timeline advancing but discards accelerated samples before host playback, then fades normal output back in.

Video Block

Runtime video defaults live in [video]:

[video]
renderer = "opengl"       # "software", "opengl", or "vulkan"
offer_vulkan = false      # show Vulkan in the launcher only after game validation

renderer = "vulkan" remains an experimental runtime choice and still requires a build compiled with Vulkan support. offer_vulkan controls launcher visibility only; it defaults to false so game projects must explicitly expose Vulkan after validating their visuals and stability.

Reserved future fields:

• default_disc_path — game runtimes can pre-mount a disc
• default_game_root — for sibling-junction setups

Audit block

See docs/audit_inventory.md for the audit pipeline. The schema here is the input side: regions to walk, address-normalisation rules.

[audit]
function_starts = "generated/ghidra_function_starts.json"   # optional

[[audit.regions]]
name        = "..."             # e.g. "Boot", "Kernel", "Shell", "Text"
rom_start   = "0x..."           # byte offset in rom/exe file
rom_end     = "0x..."           # exclusive
vaddr_base  = "0x..."           # virtual address corresponding to rom_start

[audit.normalize]
kseg_mask = "0x1FFFFFFF"

[[audit.normalize.remap]]
description = "..."             # human-readable; not consumed by tooling
from_lo     = "0x..."           # inclusive
from_hi     = "0x..."           # exclusive
to_lo       = "0x..."           # target start offset (phys = phys - from_lo + to_lo)

What's NOT in the schema yet (Phase B+)

These are noted here so future work knows where to slot them:

• Game discs field (Phase D). For now Tomba uses disc = "...".
• [runtime] disc_swap_command — runtime-side disc swap (Phase D).
• [recompiler] seeds as an array of paths (currently single file; Phase A might allow multiple).
• [program] type explicit discriminator (currently inferred from rom vs exe field presence).

BIOS profiles (bios/<STEM>.toml)

One profile per BIOS image; the profile is the single source of truth for the image identity, the relocation windows, and the runtime anchors. Two ship: bios/SCPH1001.toml (retail; user supplies the dump) and bios/OpenBIOS.toml (MIT, redistributable, shipped with the build). Normal runtimes link both generated backends (PSXRECOMP_BIOS_STEMS=OpenBIOS;SCPH1001) and select one at launch. The recompiler's [recompiler] bios_config identifies the profile used for game code generation; it does not choose the player's runtime BIOS.

[program.image]              # identity; recompiler refuses a mismatched ROM
sha256          = "..."      # pins the exact image (empty = unchecked)
redistributable = false      # true: BIOS ships with the game; runtime hides
                             # any requirement to provide that image

[recompiler.address_model]   # boot-time bulk code copies out of ROM
normalize_mask = "0x1FFFFFFF"
[[recompiler.address_model.copy]]
name         = "Kernel Part 2"   # comment label in the emitted C
rom_lo       = "0x1FC10000"      # [lo, hi) physical, hi EXCLUSIVE
rom_hi       = "0x1FC18000"
ram_lo       = "0x00000500"      # physical RAM destination
runtime_base = "0x00000500"      # vaddr the CPU executes the copy at
dispatch_key = "ram"             # "ram": functions keyed by RAM address;
                                 # "rom": RAM alias folds back to ROM
kernel_bless = true              # runtime may byte-verify + run native

[[recompiler.install_slots]] # kernel-RAM PCs the BIOS patches at runtime
ram_addr = "0x00000CF0"

[recompiler.runtime_exports] # per-image HLE anchors (omit = unavailable)
shell_entry_phys  = "0x00030000"
deliver_event_ret = "0x80001720"

Every copy entry is a claim that the boot copy is byte-verbatim; the runtime kernel-bless memcmp enforces it. A BIOS with no copies (runs entirely from ROM) is valid: normalization degenerates to the KSEG mask. Semantic invariants (disjoint windows, no fold-output/input intersection, single bless window) are enforced at load; violations refuse to build.