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

How the two configs relate:

• Scalar keys (debug_port, window_title, memcard_dir, ...): these come from game.toml only. There is no BIOS→game inheritance. An earlier version of this document described a shallow override where the game won and otherwise inherited from bios.toml; that merge was never implemented. load_bios_config (recompiler/src/config_loader.cpp) is called only from the recompiler front-ends — main_bios.cpp, and main_psx.cpp purely to build the BiosAddressModel — and never from runtime/src/main.cpp. Setting a [runtime] scalar in a BIOS toml has no effect on a game run. Runtime precedence is: environment > CLI > settings.toml > game.toml > compiled-in default.
• [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
[prepare_disc]  # optional; data-track digests for prepare/verify
[netplay]       # optional; TOC / cue policy for online
[recompiler]
[draw_distance] # optional; opt-in far-geometry clamps (below)
[runtime]
[timing]        # optional; title timing constants (below)
[audit]

[prepare_disc] digests identify the main track only. See disc companions for the separate SBI input gate, exact revision coverage, and preparation receipts. No SBI configuration key is required.

Netplay disc mount ([netplay])

Optional. Online play needs the same CD geometry on every peer — data-track CRC/SHA alone cannot distinguish a Track-01-only dump from a full Redump multi-track cue. The runtime mounts the resolved path, fingerprints the TOC (disc_fp), and gates Host/Join on netplay_ok. Peers also exchange disc_fp through the lobby (disc_mismatch on join).

Field	Default	Description
require_cue	false	Require a .cue mount (reject bare .bin / cue→bin fallback)
required_tracks	0	Exact iso_track_count when > 0 (e.g. MotK Redump = 17)
required_leadout_lba	unset	Exact lead-out LBA when set
required_disc_fp	""	Exact lowercase hex SHA-256 TOC fingerprint when non-empty
required_disc_fps	unset	Multi-disc: array parallel to [game] discs, the TOC fingerprint of each disc. Each disc of a set has its own TOC, so a set gated only on required_disc_fp (the boot disc's) refuses online play on every other disc the launcher lets the player select. A disc with no entry falls back to required_disc_fp.

The whole [netplay] policy is resolved per mounted disc, not once per build — required_tracks and required_leadout_lba are per-disc facts too (a set may mix a CD-DA disc with a data-only one, and the lead-out LBA is the disc's size). Only required_disc_fps carries per-disc data today; the resolution point is netplay_expect_for_disc() in runtime/src/main.cpp, and that is where the others go when a title needs them.

Offline Play may still launch with a TOC warning; first-run setup Finish and online Create/Join require netplay_ok (and online also a clean verify + non-empty disc_fp). Mirror required_tracks in the Retro catalog as rom_identity.track_counts so the hub library scan rejects Track-01-only dumps. Wizard / Retro / catalog submission accept Redump .cue + sibling .bin tracks, or a MAME-compatible .chd of the same dump: tools/psx_chd.py reads it through the libchdr the emitters build (CMake target chdr) and writes the Redump-shaped track files back, so [prepare_disc] digests, SBI companions and required_tracks apply unchanged. A bare .iso cannot expand to multi-track.

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]
disc_serials	game (multi-disc, optional)	array parallel to discs: the serial each disc carries (["SCUS-94163", "SCUS-94164", "SCUS-94165"]). Without it every disc is checked against [game] id — the BOOT disc's serial — so selecting disc 2 reports "wrong disc". A disc with no entry here is not serial-gated; the ISO-header check still applies.

Multi-disc selection

Relative paths in executable-side settings.toml ([disc] path, [bios] path, [memcard] dir, card1, card2) and in disc.cfg / bios.cfg resolve from the executable directory, including when launched from another working directory. Absolute paths and UNC paths keep their original location. A relative --disc command-line argument still resolves from the caller's working directory.

A build whose discs array has more than one entry grows a Disc Selection dropdown in the launcher, above the Serial/Region/ISO-header checklist. The choice is persisted in settings.toml:

[disc]
path     = "/abs/path/Game (Disc 2).bin"   # the image actually mounted
selected = 2                               # 1-based index into [game] discs

selected names the disc and path only survives when it is that disc (same file-name stem), so writing selected alone — from an external launcher or by hand — switches discs even though path still points at the previous one. That is what makes disc choice manageable like any other setting. Both keys are written only for multi-disc titles.

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.

Guarded packed-coordinate rejection

Some polygon funnels combine packed SXY flags and reject on BNE flags,zero. The native-wide GPU can clip horizontal overflow while the game retains its vertical rejection bits. Declare only verified render rejection branches:

[[widescreen.cull.masked_reject]]
address = "0x80021ECC"
expected = "0x15E0FFC7"
reject_mask = "0xFFFF0000"

The full instruction guards each site on static, cached-overlay and interpreter paths. At native 4:3, menus and FMV the original predicate is unchanged. During wide gameplay only the specified flag bits participate in the predicate; guest registers, the branch delay slot, vertical/depth/backface tests and timing remain intact. Adapters must provide sufficient bounded primitive/capture capacity. Changing a site, guard or mask changes the overlay configuration fingerprint.

Guarded widescreen participation comparisons

[[widescreen.cull.packed_x]] handles a proven mesh screen-X predicate expressed as SLTU rd, (SX << 16), (width << 16):

[[widescreen.cull.packed_x]]
address = "0x801466A0"
expected = "0x0079C02B"

The complete instruction guards native overlays and the interpreter. While wide, X must lie in [-margin, width + margin); both sides widen together. At 4:3 the original unsigned comparison is exact. Nonzero low-half operands, zero width, and widths above 1024 retain the original comparison. It changes only the predicate, preserving GPR operands, vertical, backface, depth and ordering-table limits. Sites affect the overlay cache identity; regenerate main/native overlays after changing them. Empty lists are inert.

Games may disable a proven object/model cull verdict in widened world views without changing true 4:3 behavior:

[[widescreen.cull.keep]]
address = "0x8002B310"
expected = "0x28A21C01"
result = 1

• expected must encode SLT, SLTU, SLTI, or SLTIU.
• result must be 0 or 1.
• The site identity is the normalized physical address plus the complete 32-bit instruction. A nonmatching overlay variant at the same VA is left unchanged.
• At true 4:3 the original comparison is evaluated. The configured result is forced only when psx_ws_x_margin() > 0.
• Native generated code and the dirty-RAM interpreter implement the same semantics.
• Regenerate main/overlay native code after changing the list.

Packed-SXY all-vertices rejects

[[widescreen.cull.sxy]]
kind = "quad"
vertex_regs = [8, 20, 11, 9]
fold_addresses = ["0x8001A9B4", "0x8001A9B8", "0x8001A9BC", "0x8001A9C0"]
fold_expected  = ["0x01110824", "0x02810824", "0x01610824", "0x01210824"]
consumer_address  = "0x8001A9C4"
consumer_expected = "0x14200049"

• kind is "tri" (3 vertices) or "quad" (4); vertex_regs, fold_addresses and fold_expected have one entry per vertex.
• Every fold_expected is and r, ... into the same r != $zero; the first reads vertex_regs[0] and a separate mask register, each later one reads its vertex and r. consumer_expected is beq/bne r, zero.
• Addresses are word-aligned, in one segment, strictly increasing, the fold within 16 instructions and the consumer within 4 after it; no address is shared with another sxy site. At most 64 sites.
• Identity at 4:3; while widened only the X-sign bit of each AND changes. See docs/WIDESCREEN.md.

Prefer an aspect-derived cone over keep when the original predicate is a camera-frustum test. keep has no queue policy and is appropriate only for a separately proven binary verdict.

Aspect-aware terrain and model participation

Exact terrain-frustum angle loads can follow the live horizontal field:

[[widescreen.cull.angle]]
address = "0x8013F138"
expected = "0x24020155"

expected must be ADDI/ADDIU rt,zero,imm, with a positive 12-bit angular half-extent below one quarter-turn. The helper widens tan(angle) by the live per-side horizontal extent. It is exact at 4:3 and full-word guarded against same-address overlay variants.

A model-list or per-child cosine rejection can use a horizontal-only envelope:

[widescreen.cull.aspect_cone]
forward_addr = "0x1F8000E8" # signed Q12 X/Z/Y halfwords
object_type_offset = 12
object_reg = 19
x_reg = 16
z_reg = 17
y_reg = 18
hysteresis_pixels = 24
queue_reserve = 4
queue_count_addrs = ["0x1F800144", "0x1F800150", "0x1F80015C"]
queue_capacities = [24, 40, 28]
queue_type_masks = ["0x00000204", "0x00000010", "0x00000020"]

[[widescreen.cull.aspect_cone.sites]]
address = "0x80077368"
expected = "0x28620358" # signed SLTI reject predicate

[[widescreen.cull.aspect_cone.sites]]
address = "0x8002B368"
expected = "0x0082202A" # signed SLT reject predicate
cosine_threshold = 856  # required for SLT; Q10
object_reg = 20         # optional per-site register overrides
x_reg = 19
z_reg = 18
y_reg = 17
queue_guard = false     # this lower-level predicate appends to no fixed queue

• Sites must be signed SLTI or SLT reject predicates: zero is the keep path and one is rejection.
• An SLTI site derives its Q10 cosine threshold from the immediate unless cosine_threshold is given. An SLT site requires it explicitly.
• A vanilla keep is always preserved. Only a vanilla rejection is retested.
• Horizontal reach follows the current client aspect. Vertical reach, near/far checks, type dispatch, and the game’s queue-capacity branches are unchanged.
• guard_pixels is the activation guard outside the visible field. hysteresis_pixels moves deactivation farther out.
• For queue_guard = true, non-visible guard/hysteresis candidates are rejected at capacity - queue_reserve, preserving headroom for candidates intersecting the visible wide field.
• Use queue_guard = false only after proving that the exact predicate does not append to those queues.
• Site address, instruction, threshold, registers, queue policy, guard size, and enclosing cone/queue metadata all contribute to overlay cache identity.
• Generated/native overlay code and the dirty-RAM interpreter use the same live helper. Dynamic resizing therefore needs no recompilation.

The debug server’s ws_aspect_cone_site command accepts an address string and reports exact-site identity/keep/reject counters.

Signed horizontal bounds can be widened at the constant-load site:

[[widescreen.signed_x_bound]]
address = "0x800BD290"
expected = "0x2402FF00" # addiu v0,zero,-256

• LUI rt,imm sites are signed Q16 gameplay bounds and use the gameplay-field scaler.
• ADDIU rt,zero,imm and ORI rt,zero,imm sites are screen-pixel bounds and move by the live horizontal margin. ADDIU sign-extends the constant; ORI zero-extends it. The destination and immediate must both be nonzero.
• Site identity is the normalized physical address plus the complete instruction word. The helper is identity at 4:3.

Signed per-vertex screen-X culls can be listed site by site (slti_sites, slti_lower_sites, bltz_sites, bgez_sites, clip_edge_x_load_sites with clip_edge_width, branch_keep_sites). All are identity at 4:3, empty by default, and need a regen; docs/WIDESCREEN.md ("Explicit screen-X cull sites") has the semantics of each kind:

[widescreen.cull]
bgez_sites = ["0x80013F40"]              # bgez SX,keep: keep while SX >= -margin
bltz_sites = ["0x80013F58"]              # bltz SX,reject: reject while SX < -margin
clip_edge_x_load_sites = ["0x8005F5F4"]  # lh of a clip bound: 0 -> -m, W -> W+m
clip_edge_width = 320                    # 1..1024; default screen_w_imms[0]

• Main-EXE generation fails (exit 1) when a listed address does not hold the expected instruction: slti for both slti kinds, exactly bltz / bgez, lh/lhu/lw to a nonzero register for clip-edge loads, and a conditional branch (beq, bne, blez, bgtz or REGIMM) for branch_keep_sites.
• bgez_sites and clip_edge_x_load_sites (with the width) contribute to the overlay-cache identity only when non-empty.

Explicit bias_sites / bias_lower_sites / range_sites may opt into an additional resident object lead without widening terrain or render queues:

[widescreen.cull]
guard_pixels = 16
activation_guard_pixels = 256
bias_sites = ["0x80069BA8"]
range_sites = ["0x80069BB0"]

activation_guard_pixels is added only to the live margin emitted at those three explicit site families, and only while widescreen reveals extra world. At true 4:3 it is exactly zero. guard_pixels remains the shared render/terrain participation guard; keep it small when terrain producers or model queues have fixed capacity. Both values are restricted to [0, 256] and contribute to native-overlay cache identity. Changing the activation guard requires regenerating the game and overlay code.

bias_lower_sites is the lower-endpoint counterpart to bias_sites: an ADDI/ADDIU camera-relative bound subtracts the activation margin from its original immediate. Both native code and the dirty-RAM path apply it. For strip-based enemy spawning, expand the outer strip edge, initial and vertical scan X bounds, and any associated respawn-reset interval together. Keep authored placement flags and vertical bounds intact. Empty is inert; configured sites require regeneration.

Draw-distance clamps ([[draw_distance.clamp]])

Many PS1 renderers drop a primitive whose depth index falls past the end of their ordering table (sltiu t, z, N; beqz t, reject). The limit protects the OT, so raising it can write past the table. A title can list such guards and let a trusted mod keep the far primitive in the farthest slot instead:

[[draw_distance.clamp]]
address  = "0x80061230"
expected = "0x2C4A01C0"  # sltiu t2, v0, 0x1C0
reg      = 2             # v0: the depth index the guard tests
max      = 0x1BF         # last safe index

[[draw_distance.clamp]]
address  = "0x80066FF8"
expected = "0x2441FFFF"  # addiu at, v0, -1 (then sltiu at, at, 0x1BF)
reg      = 2
max      = 0x1BF

• While a mod has called psx_mod_set_draw_distance_clamp(1), reg is clamped to max (signed: if ((int32_t)reg > max) reg = max) immediately before the instruction at address runs. The original guard then keeps the primitive and the code that follows indexes the table with the clamped value. A negative (wrapped) value is left alone, so a guard that also rejects too-near primitives keeps doing so.
• Off, the default and the state at every session start, the sites run the original code. Netplay never activates a mod, so it stays vanilla.
• expected is the complete instruction word and must be an ALU instruction (ADDI/ADDIU/SLTI/SLTIU/ANDI/ORI/XORI, or a SPECIAL shift/arithmetic/logic/SLT/SLTU) that reads reg. reg is 1..31; max is a signed 32-bit integer. Addresses are unique by physical address.
• Main executable only. Generation fails when the listed word is not expected, or when the previous instruction loads reg (its value would still be in the load-delay slot). Captured overlay code at a listed address keeps its own code, so the sites do not enter the overlay-cache identity. The dirty-RAM interpreter applies a clamp where the game's text image holds the listed word.
• Pick max so the clamped index reaches no further than the farthest index the unclamped code can already produce. Choose the register the following code really indexes with: in the addiu form above, the guard tests at but the slot is computed from v0.
• Regenerate after changing the list. With no sites the generated code is unchanged.

Mod immediates ([mod_immediate])

A trusted mod sometimes needs the same compiled instruction to behave differently from one session to the next without changing the guest bytes (a capacity compared against slti v0, a0, 32, a table address formed by addiu a1, a1, 0x6988, a struct offset in lbu v0, 0x2E9(v1)). Patching RAM fails for statically compiled code: every function carries a CRC of its original bytes and a patched function drops to the interpreter. Listing the instruction as a mod immediate site keeps the bytes and the CRC, and moves the choice into the generated code:

[mod_immediate]
sites = [
  { address = "0x80023500", expected = "0x28820020", group = 1, values = [0x40, 0x80] },  # slti v0, a0, 0x20
  { address = "0x80023B14", expected = "0x24A5AEB1", group = 1, values = [0xAEB1, 0x9000] },
]

• expected is the complete word at address and must be an I-type ALU instruction (ADDI..LUI, opcodes 0x08-0x0F) or a byte/half/word load or store (LB..SW, 0x20-0x2B). Branches, jumps and R-type instructions are refused. group is 0..63; values lists up to 15 replacement 16-bit immediates (decimal, hex, or negative), selector 1 first.
• Selector 0 is the original instruction. A trusted plugin selects variant N of every site in a group with psx_mod_set_immediate_selector(group, N) from its activation callback; the selector is 0 again at every session start, so an inactive mod, a disabled feature and netplay all run the stock code.
• Generated code emits switch (psx_mod_immediate_select(group)) with one case per value, each translated exactly like the instruction it stands for (cycle accounting, PGXP hooks, load-delay handling), plus the original as the default. The dirty-RAM interpreter substitutes the same word (psx_mod_immediate_patch), so native and interpreted execution agree. The forwarder is part of the overlay ABI (v31).
• A site is keyed by physical address and word. Overlays share load addresses, so one address may carry several sites with different words; a variant whose word differs is left alone in overlay mode and is an error in a main EXE.
• The sites enter the overlay-cache identity (the hash changes only when the list is non-empty). Regenerate after changing the list; with no sites the generated code is unchanged.
• The mod owns the consequences: a relocated table needs its own free memory and a save written under one selector is not interchangeable with another's.

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]
idle_skip = true
turbo_audio_sink = true
overlay_region_floor = "0x10000"   # optional: lowest RAM address treated as overlay region.
                                    # Default = boot EXE text end. Lower it for titles whose gameplay
                                    # code loads at/inside the boot text range (GT1 secondary EXEs at
                                    # 0x80010000, Driver 2 mission pages) so it is overlay-cache
                                    # eligible. Clamped >= 0x10000; PSX_OVERLAY_REGION_FLOOR overrides.

idle_skip only elides loops with no stores and one interrupt-check edge. idle_skip_store_counters = true (with idle_skip; PSX_IDLE_SKIP_EXT=0/1 overrides it for one run) also elides loops that count a stack timeout down by one each pass and span up to eight block edges: PsyQ libetc's v_wait, the VSync(0)/VSync(n) spin most PsyQ titles run every frame. The skip lowers the counter by the number of passes it skips (several edges per pass are accepted only together with such a counter store; the device distance is measured from the current cycle, not from the devices' last service) (never to 1 or below, so the real timeout test still runs) and lands on the loop's first edge strictly before the next device event, so an interrupt is taken at the same edge as without it. Guest cycles, device-register writes and scratchpad writes are unchanged; the only difference is that the skipped passes' stores to the counter word are not individually made (frame_fingerprint wc/ws count fewer writes, its judge columns match). In R4 races it removes about a quarter of the emulation thread's time. Off under netplay, like idle_skip.

Developer contract for idle_skip_store_counters

Eligibility is an audited allowlist, not an automatic guarantee. The detector can check a loop's shape over the passes it observes. It cannot prove that the loop has no later exit that depends on the counter (for example, an exit at counter == 500): a skip would jump past it. So the extension only skips at sites the title's developer has audited and declared:

[runtime]
idle_skip = true
idle_skip_store_counters = true
# Block-edge PCs of each audited loop (the detector anchors on either).
idle_skip_store_counter_sites = ["0x8008B4D0", "0x8008B518"]

Unlisted sites are never skipped. An empty or missing list turns the extension off, and the runtime log says so. Before adding a site, read the loop's code and record its exit structure next to the list: every exit that depends on the counter must be the final timeout test (the counter reaching the value the skip stops short of), and no other code may read the counter.

R4 (SLUS-00797) is the reference audit. PsyQ libetc v_wait sits at 0x8008B4A8:

1. It stores timeout << 15 to 0x10(sp) and returns at once if the VSync count at 0x800A6548 has already reached the target.
2. 0x8008B4D0: it loads the counter, subtracts 1, stores it and reloads it. If it equals -1 it takes the timeout path (0x8008B4F0: prints "VSync: timeout", calls ChangeClearPAD(0) and ChangeClearRCnt(3, 0), then jumps to the exit).
3. 0x8008B518: it reloads the VSync count and branches back to 0x8008B4D0 while the count is still below the target.
4. 0x8008B530: the exit.

The only exit that depends on the counter is the == -1 timeout test. The skip never takes the counter to 1 or below, so that test always runs for real. The counter is a private stack slot of this frame.

A skip leaves out stores to the counter word that the guest would have made. That is invisible only if nothing observes the word between those stores. The assumptions, and how each one is enforced:

Assumption	Enforced by
The loop makes exactly one guest store per pass: a 4-byte-aligned word in RAM or the scratchpad, at the same address every pass, one lower each pass.	idle_stores_ok plus the address/value check at the anchor. Any other store count, any device or BIOS-area address, or a changed pattern resets the detector.
The loop touches no MMIO, so it cannot start DMA, acknowledge an IRQ or poll a device mid-span.	g_mmio_access_count must be unchanged across the pass.
Everything else in the pass is a pure function of the registers. Only the counter register and the counter word progress; every other GPR is invariant at the anchor.	The register snapshot is compared at the anchor; one progress register is allowed, and only if it moves in step with the word.
No other observer (IRQ handler, DMA, timer, SPU, CD, GPU, host-side mod or debugger code) runs between two device events.	The skip lands on the anchor strictly before the next scheduled device event, measured from the current cycle. Every IRQ, DMA completion and VBlank callback therefore sees the counter value that unskipped execution would have stored at that same edge. Host mod hooks run only at VBlank or at function entry, and neither happens inside the span.
The loop has no exit that depends on the counter, except the final timeout test.	Not checkable by the detector. It is the caller's audit: only the sites listed in idle_skip_store_counter_sites are eligible.
The loop's own exit test still runs.	The counter is never lowered to 1 or below, so the --timeout == -1 path executes for real.
The game does not read the counter word through another pointer, inside or outside the loop.	Partly checked: a read that changes a register or the edge count resets the detector. Otherwise this is part of the site audit.

What differs from unskipped execution: the guest store count (frame_fingerprint wc/ws) and the host time. Guest cycles, device-register writes, scratchpad and RAM contents at every device event are the same. That is why the judge columns cyc, mmio, mc, sp, sc and qc must match. A title that breaks one of the assumptions in a way the detector cannot see (for example, a second CPU-side writer driven by a device it does not schedule) must leave the key off.

Evidence (R4, OpenBIOS, M4 release build with debug tools, frame_fingerprint, key off vs on):

• boot into attract: 9000 frames
• race from a savestate: 3600 frames
• all judge columns identical, 0 dispatch misses
• wc/ws lower with the key on

The other psxrecomp titles have no disc in this test setup, so they keep the key off until they are run the same way.

turbo_loads / offer_turbo_loads — deprecated and ignored

Do not use these keys. Load acceleration is owned by the Mods catalog: psx.enhancement.fast-loading ("Fast Loading (host pacing)") and psx.enhancement.cd-speed. Both target game_id = "*", so they ship with every title, both default to off, and both expose the multiplier and instant-scheduler detail that a single opaque boolean never could. recomp-ui correspondingly draws no generic Turbo loads row.

Both keys are still parsed so existing configs load without error, but neither is honoured — the runtime logs a deprecation line naming the Fast Loading mod and leaves acceleration off. Remove them from game.toml.

The same applies to [video] turbo_loads in a user's settings.toml: it is no longer restored at startup, and it is no longer written back out, so the stale row disappears on the first save after updating. This is deliberate. Because the launcher stopped drawing a control for it, a persisted true was simultaneously authoritative and unreachable: one run of a build whose game.toml said true latched turbo on permanently, and no later config change could undo it. That shipped to players in MegaManX6Recomp v1.0.4/v1.0.5 (MegaManX6Recomp#14). Never restore this row without also restoring a UI control for it.

For development, the turbo_loads TCP debug command still toggles acceleration at runtime.

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

Audio Block

Game projects may choose the host playback cushion after validating their audio production cadence:

[audio]
buffer_ms = 60

buffer_ms accepts 30–500 milliseconds and defaults to 180. Lower values reduce audible input-to-sound delay, but leave less reserve for frames where a game temporarily produces no audio and can therefore crackle on affected titles. This is deliberately a per-game developer choice; it is not read from the player's settings.toml.

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
auto_skip_fmv = false     # legacy Settings/runtime default
offer_skip_fmv = true     # false when the game exposes this through Mods

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.

Graphics presets ([quality.low|medium|high|ultra])

Optional named presets of supported [video] keys (the set is listed in QUALITY_PRESETS.md; any other key is a load error), laid over [video], with hardware detection on first launch, a launcher Graphics preset row, Re-detect and a Custom state. See QUALITY_PRESETS.md.

Internal resolution (internal_resolution, supersampling)

The player picks a preset in Settings → Display → Internal resolution: Native, 720p, 1080p, 1440p, 4K, 5K, 8K or Match display. It is stored in the player's settings.toml, and a game may ship a default the same way:

[video]
internal_resolution = "4k"          # native | 720p | 1080p | 1440p | 4k | 5k | 8k | display, or a number of lines
resolution_reference_lines = 240    # game.toml only: the title's usual display height (120..1024)
supersample_disable_at_lines = 0    # game.toml only: supersample 1.0 at/above this display height (0 = off, 240..8640)
match_display_max_lines = 0         # game.toml only: cap on the display height Match display uses (0 = none, 240..8640)

match_display_max_lines caps the monitor height that Match display, its dynamic-resolution floor (display) and graphics-preset detection resolve against. It also caps the final Match display target after supersampling, so a larger saved factor cannot exceed it. Fixed presets keep their own target. With no cap, an 8K panel asks 18x (27x with supersample = 1.5), which is past the full-VRAM surface. The high-resolution window then engages, and dynamic resolution cannot step there. A title whose GPU budget is set for 4K lines sets 2160.

supersample_disable_at_lines uses the physical monitor height before the cap. At or above its threshold the effective factor is 1.0; the saved factor is retained for smaller monitors. Zero preserves the default behaviour.

A preset is a target height. The runtime renders at the integer scale S = ceil(target / resolution_reference_lines): at the default 240 lines, 720p is 3x, 1080p is 5x (1200 lines, area-resolved to 1080), 1440p 6x, 4K 9x, 5K 12x and 8K 18x. A 480-line interlaced screen renders at twice the target and is resolved down. Match display takes the monitor's pixel height, measured from the game window's display when it opens. The backend clamps S to what it can allocate (below); video_info over TCP reports both numbers.

Precedence: the game's internal_resolution is the default; a player's legacy supersampling in settings.toml outranks it; the player's own internal_resolution outranks both. The launcher writes the preset as a stable id ("4k") beside supersampling = min(S, 4), so an older runtime reading the same file still gets the nearest factor it supports. A legacy factor with no matching preset appears in the launcher as its own entry, for example "2x (480 lines)". settings.toml window_width accepts 640 to 7680.

A host built against a recomp-ui without the Internal resolution row keeps the legacy Supersampling row (1x to 4x) and that row stays in charge: with no preset configured the launcher round trip is exactly the historical one, and no internal_resolution key is written. A preset from game.toml or a hand-edited settings.toml starts the row on the nearest factor it can show and survives if the row is left alone; picking a different factor there drops the preset.

PSX_INTERNAL_RESOLUTION=<preset or lines> overrides every layer for one run (validation, and two local netplay peers that share one settings.toml). It is never written to settings.toml: the launcher shows and saves the configured preset.

On OpenGL, any choice above native opens the game window with a high-pixel-density drawable (macOS Retina, Wayland scaling), so the window has the pixels to show it. Native keeps the window exactly as before.

supersampling = N renders at N times the native resolution per axis and downsamples to the window. It accepts 1 to 32 in both game.toml and the player's settings.toml; 1 (the default) is native and unchanged.

Bloom (bloom)

Opt-in glow around lights, OpenGL only. Off (0) changes nothing.

[video]
bloom = 1.0                     # 0.0 (off, default) .. 2.0 strength

Only what 3D primitives (proven from GTE data, so it needs PGXP geometry) and additive semi-transparent primitives (blend modes 1 and 3) drew can glow: each draw marks its pixels in a spare stencil bit, and a sprite, fill or HUD element drawn over them clears the mark. The marks gate both ends of the pass: only marked pixels feed the bright pass, and only marked pixels take the glow back, so a HUD, sprite or fill pixel is never changed, even right next to a lamp (the halo spreads over 3D surroundings only). The pass runs on the composed game image like antialiasing_mode (before it, sharing its copy texture and full-screen pass): a quarter-resolution bright pass, three Gaussian iterations and a screen blend. It follows 4:3, native-wide, supersample, dynamic resolution, the render thread and Smooth motion (generated frames carry the marks of the frame they are drawn from). Without PGXP geometry only additive primitives glow. Bloom is the built-in bloom chain of the post-effect pipeline (docs/POST_EFFECTS.md), which also loads your own chains through post_shader = "<file>.pfx" (relative to the game root; PSX_POST_SHADER). PSX_BLOOM=<0..2> overrides it for one run and the bloom TCP command reads or changes it live. It is one of the supported quality keys, so a [quality.*] preset can turn it off on low-end machines.

Anti-aliasing (antialiasing_mode, supersample)

Both are opt-in and change nothing unless set.

[video]
supersample = 1.5               # 1.0..4.0, default 1.0
antialiasing_mode = "fxaa"      # off (default) | fxaa | fxaa_hq

supersample multiplies the target of a line preset or Match display before it becomes a scale: Match display on a 1080 px monitor with 2.0 asks for 2160 lines (S = 9) and the present's area resolve brings it back to 1080, which is ordered-grid SSAA of everything, 2D included. Native and the legacy supersampling factor are left alone. Dynamic resolution takes the result as its ceiling and steps under it as before. PSX_SUPERSAMPLE=<factor> overrides it for one run.

To make supersampling the elastic part only, set the dynamic resolution floor to the output: dynamic_resolution_min = "display" (also PSX_DYNRES_MIN=display and settings.toml) means the selected internal resolution without the supersample factor, i.e. the monitor's own lines under Match display or the preset's lines otherwise. Dynamic resolution then steps between the supersampled ceiling and the output and never renders below it:

[video]
internal_resolution = "display"
supersample = 2.0
dynamic_resolution = true
dynamic_resolution_min = "display"

antialiasing_mode filters the composed game image on OpenGL: after the game quad (4:3, native-wide, Smooth motion and generated frames alike) and before hold-last capture, the OSD, screenshots and the swap. It reads only output pixels, so guest VRAM, readbacks, render passes and the Smooth motion sources are untouched; the bezel and OSD stay sharp; 24-bit FMV frames are not filtered. The PS1 HUD is part of the same image and is filtered too. fxaa is one copy and one full-screen pass (on an M4, at most 0.4 / 0.7 / 1.5 ms at 1080p / 1440p / 4K, fence-timed with the copy); fxaa_hq lowers the contrast threshold and searches further along long edges. PSX_AA_MODE=off|fxaa|fxaa_hq overrides it for one run and the post_aa TCP command switches it live. The older boolean antialiasing key is unrelated: it is the linear present filter the launcher already persists.

Not offered: MSAA. The hi-res surface is guest VRAM (texture pages, CLUTs, VRAM copies, readbacks and the mask stencil all sample or copy it between draws), so a multisampled target would need a resolve before every one of those and the mask/semi-transparency rules would have to run per sample; that is a renderer redesign, not an option. SMAA needs its area/search lookup textures and three passes; on an image that is already area-resolved from a higher internal resolution it buys little over FXAA, so it is left for later.

FMV chroma smoothing (fmv_chroma_smoothing)

[video]
fmv_chroma_smoothing = false   # default
fmv_filter = "bicubic"         # optional upscale filter (needs antialiasing on)

MDEC movies are 4:2:0: one colour (Cb/Cr) sample per 2x2 pixels, which the decoder replicates, so saturated edges in a 24-bit movie frame show 2-pixel colour blocks around sharp luma. With fmv_chroma_smoothing = true the OpenGL present of a 24-bit frame keeps each sample's luma (from whatever fmv_filter reconstructs) and takes its chroma from a [1 2 1] tent over the 3x3 source pixels around it (BT.601), which removes the colour blocks without softening luma detail. Guest VRAM and MDEC output are untouched; 15-bit frames are never affected. It pairs with the existing fmv_filter upscale choice (nearest, bilinear, sharp, bicubic). OpenGL only. PSX_FMV_CHROMA=0|1 overrides it for one run and the fmv_chroma TCP command switches it live.

Texture LOD and anisotropic filtering (texture_lod, anisotropic_filtering)

[video]
texture_lod = "off"          # off (default) | mipmap
anisotropic_filtering = 1    # 1..16, taps along the footprint (with mipmap)

PS1 texture pages and CLUTs live in VRAM and are decoded per fetch, so there is no GL mip chain to sample, and a far road or wall at high internal scale still point-samples one texel per pixel (shimmer). mipmap emulates the mip level in the textured shader: the screen-space UV footprint is box-averaged (opaque texels of the same STP class only), and anisotropic_filtering > 1 spreads up to that many taps along the footprint's long axis so grazing surfaces stay sharp across it. Every tap clamps to the primitive's own UV bounds (or its texture window), so packed atlases never bleed into each other, and a live CLUT change is seen at once (nothing is cached). Only proven 3D world primitives are affected; sprites, HUD and magnified textures keep their exact texels, and off is the historical path. Cost is up to 64 fetches per minified pixel. OpenGL only. PSX_TEXTURE_LOD=0|1 and PSX_ANISO=N override them for one run; the texture_lod TCP command switches them live.

Accurate blending (accurate_blending)

[video]
accurate_blending = true     # default: PS1 colour/blend correctness

Accurate blending is enabled by default because it corrects PS1 rendering. false retains the historical path for diagnosis.

The OpenGL surface holds each 5-bit VRAM channel as an 8-bit value. Uploads, copies and untextured primitives store k*8, but fills and texels have always stored k*255/31 (full-range white). Semi-transparent blending of two operands in different bases, truncated back to 5 bits when the game reads VRAM, is off by one step in places: B+F/4 over a fill, B/2+F/2 with an odd sum, B+F/4 of a texel. true makes every VRAM write use k*8, so GL's 8-bit blend followed by the readback's >>3 is exactly the PS1's 5-bit arithmetic in all four modes (B/2+F/2, B+F, B-F, B+F/4), with set-mask, mask check, texel STP and PGXP depth, at any internal scale and on drivers that quantise the blend constant to 8 bits (it uses 128/255 and 64/255, exact in unorm8, instead of 0.5 and 0.25) (checked against the formulas and the software rasterizer by gl_blend_accuracy_test). The visible cost: textured and filled whites present as 248 instead of 255, as uploaded images and untextured primitives already do. One divergence remains in both settings: a second semi-transparent layer blends with the first layer's full 8-bit result where the console would have truncated it to 5 bits first (at most one 5-bit step). OpenGL only. PSX_ACCURATE_BLENDING=0|1 overrides it for one run and the accurate_blending TCP command switches it live.

Dithering (dithering)

[video]
dithering = "on"      # on (default) | fine | off

The PS1 GPU dithers while the game sets GP0(E1h) bit 9: it adds a 4x4 offset pattern to every pixel of a Gouraud-shaded polygon or line and of a texture-modulated polygon, then truncates to 5 bits per channel. Flat untextured primitives, raw-texture polygons and all rectangles (sprites) are never dithered. Eligibility is decided per primitive from its command and carried to the shader, never guessed from colours.

on (the default; scaled is accepted as an alias) is that hardware behaviour with the pattern on the native VRAM grid, so it looks like the console at any internal scale and the VRAM a game reads back is identical at every scale. fine is elective: the pattern per internal-resolution pixel, a grain that all but vanishes at high scales (guest VRAM then depends on the scale). off is the old true-colour output (8 bits per channel, no pattern).

Semi-transparent primitives are an approximation: the pattern is applied to the source colour before blending, while the console dithers the blended result at its final 8-to-5-bit write. Fixed-function GL blending cannot run a shader after the blend (GL 3.3 has no framebuffer fetch, and macOS offers none), so a dithered semi-transparent pixel can differ from the console by one 5-bit step; opaque pixels match exactly. The dither output follows the surface colour basis, so it composes with accurate_blending. OpenGL only; the software and Vulkan renderers do not dither. PSX_DITHERING=0|1|2 overrides it for one run and the dithering TCP command switches it live.

Texture filtering (texture_filtering)

[video]
texture_filtering = "nearest"   # nearest (default) | bilinear | xbr

nearest is the PS1's point sampling. bilinear blends the four nearest texels (opacity-gated, so cutout edges keep their colour). xbr (OpenGL only) is edge-directed magnification after Hyllian's xBR (MIT; see THIRD_PARTY_ATTRIBUTION.md): for the texel corner nearest each sample it compares weighted colour distances over a 5x5 neighbourhood, and where an edge runs along that corner's diagonal the corner is cut and takes the closer side neighbour, with an anti-aliased boundary one output pixel wide. Flat areas, straight edges and gradients stay crisp texels; diagonals and curves lose their staircase. It acts only where a texel spans two or more output pixels (high internal scale or a magnified texture), so a 1:1 draw is exactly nearest; cutouts and STP stay the centre texel's. It costs up to 13 texel fetches per pixel. JINC2 is not offered. PSX_TEXTURE_FILTER=0..3 overrides it for one run (2 is the mod-only "stable world" minification filter) and the texture_filter TCP command switches it live. The launcher's toggle still offers nearest and bilinear.

The runtime clamps N per backend:

• Software and Vulkan stop at 4.
• OpenGL keeps VRAM as one 1024*N x 512*N surface and clamps N at context init to the driver's GL_MAX_TEXTURE_SIZE, GL_MAX_RENDERBUFFER_SIZE and GL_MAX_VIEWPORT_DIMS, and to a memory budget of 2 GiB for that surface (PSX_GL_VRAM_BUDGET_MB overrides it; 0 removes it). Apple's OpenGL reports 16384, so 16 is the largest full-VRAM scale there. A surface that still fails to allocate is retried one scale lower; the backend never drops to software because of the scale. The log line GL internal scale Nx clamped to Mx (...) names the limit that applied.

Past the full-VRAM limit (8K is 18x, over Apple's 16384), OpenGL keeps the whole VRAM at 1x — the native renderer, so everything the game reads back is exactly native — and renders only the columns it displays at the full scale, in a separate high-resolution window (5760x9216 for a 320-wide game at 18x, about 405 MiB). The window grows to cover each displayed rectangle the first time it is shown; when the displayed rectangles are too far apart for one surface (side-by-side 512-wide buffers), it splits into up to four tiles so every buffer still presents at the full scale. A copy whose source lies outside it is taken from the 1x surface. PSX_GL_HIRES_WINDOW=0 turns the mode off (the scale is then clamped as above) and =1 forces it at any scale above 1. PSX_GL_MAX_DIM=N lowers the GPU limit the backend plans with, to check a layout on a smaller GPU.

Above 1x the OpenGL present averages the whole footprint of each output pixel when the internal image is more than 1.25 times larger than the window (for example 1200 internal lines into a 1080-line window), and lines are drawn one native pixel thick at any scale.

offer_skip_fmv defaults to true for compatibility with the shared PSX Settings surface. A game migrating Skip FMVs into its built-in mod catalog sets it to false. The runtime then hides the Settings row, ignores stale persisted values, and leaves activation to the selected trusted plugin.

Render thread (render_thread, OpenGL)

[video]
render_thread = true   # default false; PSX_RENDER_THREAD=0/1 overrides

Runs the OpenGL backend on its own thread: the emulation thread records each frame's draw work and the render thread replays and presents it, so GL driver stalls leave the guest's frame. Everything the guest can read back is identical; a readback, savestate, depth24 (FMV) display, render pass or setting change makes that frame synchronous. Netplay, frame interpolation, Vulkan and software keep the synchronous path. PSX_RENDER_THREAD_FRAMES (default 2) bounds the frames in flight. See docs/RENDER_THREAD.md.

Texture-window batching (texture_window_batching, OpenGL)

[video]
texture_window_batching = true   # game.toml only; default false

The OpenGL renderer draws consecutive textured primitives in one batch while their blend, mask and filter state match. By default a GP0(E2h) texture-window change also ends the batch, although each vertex carries its primitive's texture window. With this key on, primitives with different windows share a batch. The image is the same either way; only the number of draws changes. While mask checking (GP0(E6h) bit 1) is on, a window change still ends the batch, because an opaque batch updates the mask bits of its own texels only after its colour pass.

It is for games that tile textures through per-primitive windows. Ridge Racer Type 4's split screen changes the window about 515 times a frame, which drew about 180 batches a frame instead of 17, and every batch that reaches the native-wide margins is drawn again into the wide surface. The software and Vulkan renderers ignore the key. PSX_GL_TEXWIN_BATCH=0|1 overrides it for one run, and the TCP command gl_texwin_batch on=<0|1> switches it live.

Local rewind (settings.toml)

Rewind is a player setting, not a game one: it lives in the user's settings.toml beside the runtime executable, under [video].

[video]
rewind          = false   # off by default — see below
rewind_depth    = 50      # snapshots kept: 50 / 100 / 150 / 200
rewind_interval = 15      # frames between snapshots: 1 / 4 / 8 / 12 / 15

rewind defaults to false. The ring holds whole machine snapshots — 2 MB main RAM + 1 MB VRAM + 512 KB SPU RAM, stored uncompressed — and captures one every rewind_interval frames (denser, toward 4, while an FMV runs). At the default depth that is a few hundred MB of resident memory plus a periodic multi-megabyte copy, which is not a cost to charge every host for a feature a session may never open. Turning it on is one click in the launcher's Display card; nothing is allocated until it is.

PSX_REWIND=1 / PSX_REWIND=0 override the setting either way, and PSX_REWIND_DEPTH / PSX_REWIND_INTERVAL / PSX_REWIND_FMV_INTERVAL override the tuning. A build configured with -DPSX_REWIND=OFF has no rewind at all and ignores all of these.

Netplay rollback is a separate subsystem with its own ring and is unaffected by this setting; rewind is in fact suppressed while a netplay session is active.

A title can also block Rewind while it is in a mode that must not be rewound, such as local split-screen multiplayer: a trusted mod plugin calls psx_mod_set_rewind_blocked(1) when the mode starts and 0 when it ends (runtime/include/mod_plugins.h). While blocked, opening Rewind is refused with an OSD note, no snapshots are captured (the ring keeps what it already has), and a title-allowed direct Rewind button (psx_mod_allow_direct_shortcut) is not claimed, so it reaches the game as if Rewind were off. The block clears at every mod/session reset; nothing changes for a title that never calls it.

A title that computes vibration but cannot send it over SIO to the presented pad (a NeGcon has no motors) can call psx_mod_set_host_rumble(player, small, large) every frame with DualShock motor values. The runtime drives the host pad with the louder of that and the guest's SIO motors; a value lapses 8 VBlanks after the last call and all are cleared at every mod/session reset. PSX_RUMBLE_TRACE=1 logs every change, headless included.

EXPERIMENTAL: JogCon wheel force feedback is a player setting, settings.toml [controller] jogcon_force_feedback (off by default; the launcher / in-game menu toggle writes it via RecompLauncherCSettings.jogcon_force_feedback (recomp-launcher; read behind RECOMP_LAUNCHER_HAS_JOGCON_FORCE_FEEDBACK, so other providers still build), applied live through psx_jogcon_ffb_set_player_enabled). A title may set its default with game.toml [controller] experimental_jogcon_force_feedback (off when absent); the player's setting always wins. When on, it drives a host force-feedback wheel's SDL haptics from a presented JogCon's motor commands: a constant force for turn commands 1 and 2, and a centring spring for hold. It is off by default. Gamepads and devices without constant or spring haptics are never driven. Every force has a 120 ms lifetime and is renewed each VBlank, so a pause, stall or crash leaves the wheel slack. The Rewind and save-state pause menus, disconnects and session end also stop it explicitly. The turn direction has not been checked on JogCon hardware or a physical wheel; experimental_jogcon_force_feedback_invert = true flips it. SDL has no virtual haptic device, so CI covers the driver with a recording backend and the SDL backend only against an SDL3 virtual wheel (no haptics).

Bezel artwork is intentionally not a [video] key. It is exposed as the disabled-by-default psx.presentation.bezel mod package, which draws a user-selected image resource behind the game image in OpenGL letterbox or pillarbox margins. With the mod disabled, or with no bezel image selected, margins remain the historical black clear.

Reserved future fields:

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

Timing block ([timing])

Title constants. They live in the game's game.toml, are never written to settings.toml, and are not shown in the launcher.

[timing]
guest_cycle_scale = 1           # 1..64; 1 = faithful (default)
# Optional declarative gate: the scale applies only while every predicate
# holds, judged at each VBlank edge (one inline table or an array, max 8).
guest_cycle_scale_gate = [
  { addr = 0x800AC794, value = 0x180 },            # size = 4, mask = ~0
  # { addr = 0x80010003, size = 1, mask = 0x0F, value = 5 },
]
guest_cycle_scale_gated = false # also require the mod gate (custom logic)

No CPU is emulated. Recompiled code charges the guest clock a fixed number of cycles for each MIPS instruction it runs, and VBlank, timers, CD, SPU and DMA are scheduled against that clock. guest_cycle_scale = N charges each instruction 1/N of its cost; the devices keep hardware time. Larger N means the game never runs out of frame time: N times as much game code fits between two VBlanks. A game that paces itself on VBlank keeps its speed; one that busy-waits on a frame counter spins longer in host time, which is what the gates are for.

Accounting is the same on every tier. Guest time has two entry points (psx_cycles.h): the CPU charge psx_cpu_charge() (instruction base cost, load fudge/region wait/completion, i-cache refills, BIOS HLE costs), which applies the scale, and the device advance psx_advance_cycles() (DMA, idle skips, mul/div and GTE deadline waits), which never does. Native generated code, overlay DLLs (their batched charge publishes through the cpu_charge callback into the same function), the dirty-RAM interpreter and the BIOS all charge CPU work through it; mul/div and GTE latencies are scaled where their deadline is set. At 1 the CPU charge is exactly the device advance and nothing else changes.

guest_cycle_scale_batch = true (opt-in; PSX_GCS_BATCH=0/1 for one run) scales each CPU charge where it is made and then batches it like the scale-1 path, instead of publishing every one-cycle step to the devices. The fractional carry and the flush points (stores, MMIO, interrupt checks, device deadlines) are the same, so guest-visible timing is unchanged. In R4 races, frame_fingerprint A/Bs over 9000 frames (boot to attract, 1P race, 2P VS race) agree on cyc, mmio and mc on every frame. They also end with identical ordered write hashes. The only differences are one-frame VBlank straddles of wc/sc, as documented for batched code.

The scale and selected batching profile are fixed at session startup and included in the existing netplay compatibility fingerprint. Peers with different batching choices cannot start together. Both paths use portable C; this does not authorize compatibility between otherwise different builds or replace the existing game/core/config identity checks.

Gates (all present gates must be open; with none the scale always applies):

• guest_cycle_scale_gate — RAM predicates on aligned main-RAM words ((word & mask) == value, size 1/2/4), judged at every VBlank edge, so every netplay peer and every rollback re-simulation sees the same verdict. Shut until the first VBlank that sees them hold. Needs no mod.
• guest_cycle_scale_gated = true — a trusted plugin opens the gate with psx_mod_set_guest_cycle_scale_gate(1) (mod_plugins.h) for logic a predicate cannot express, or to tie the scale to a mod that must be active for it (every mod session reset shuts the gate; mod plans are cleared online, so a mod-gated scale stays out of netplay). With only the declarative gate the scale applies online too.

The carried fraction of the scaled clock and both gate states are saved in savestates and the netplay rollback snapshot (boot_state section BS_SEC_GCS, written only when the scale is not 1). A scale other than 1 is folded into the netplay content fingerprint, so peers that differ never match. PSX_GUEST_CYCLE_SCALE=<n> overrides the scale for testing only.

Audit block

See docs/internal/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 RANGES patched at runtime
ram_addr = "0x00000CF0"          # legacy form: len 0x10, resume "jalr"
[[recompiler.install_slots]]
ram_addr = "0x00000C88"
len      = "0x30"                # bytes; the patched range is [addr, addr+len)
resume   = "fallthrough"         # "jalr" (default) | "fallthrough" | "none"

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

An install_slots entry declares kernel-RAM words the guest is EXPECTED to overwrite at runtime — the BIOS's own install stubs and, far more often, the Psy-Q libapi patchers every SDK title runs (_patch_gte, _patch_card, _patch_card2, _patch_pad). The emitter plants a compare-against-ROM hook at the range start, so a live patch dispatches into the interpreter and the guest's own instructions execute; the runtime excludes the range from the kernel-bless memcmp and resumes native at the range end. Without the declaration the patched body fails verification forever and interprets for the life of the process.

resume says how the compiled body picks up again:

resume	Continuation PC	Use for
"jalr" (default)	ram_addr + 0x10	the classic 4-word lui/addiu/jalr/nop stub, whose call returns there
"fallthrough"	ram_addr + len	the patched words ARE the function (a prologue rewrite, a NOP'd routine)
"none"	—	the patch jumps out and never returns to this body (a jr into game text)

ram_addr and len must be 4-aligned, len non-zero, ranges must not overlap, and every range must lie inside the kernel_bless window; the loader refuses the profile otherwise and sorts the list for the runtime. Finding the ranges for a new image is described in dynamic_handler_install.md.

Every copy entry is a claim that the boot copy is byte-verbatim; the runtime kernel-bless memcmp enforces it, minus the declared install-slot ranges. 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.

Immediate selector choices are fixed during offline mod activation until the next session restart. Non-stock choices isolate savestate slots through the existing content scope; live setter calls and nonzero online selection fail.