Every GameController fed the same input path (front_mac.m), so the last one moved won, and hle_hid.c reported
exactly one npad whatever the game supports. Now the first controller is player 1, with the keyboard, the next
player 2 and so on up to 8 (pad_slots.h; a removed controller frees its player and gets it back when a
controller of the same name reconnects). Player 1 stays on No1 docked and Handheld in handheld mode, player n is
on No n (No1 stays empty in handheld mode: games take Handheld and No1 both for player 1). The game's supported
npad ids decide how many play: a one-player game ({No1, Handheld}) gets every controller as player 1, a
controller past a game's last player is not used, as on the Switch. A connect or disconnect signals that npad's
style-set event through hle_signal_bound_system_event (hle_thread.c), which signals only an event still bound,
from the macOS main thread where the notifications arrive; player LEDs follow the Switch's patterns; the
controller-support applet reports the connected players, capped at the game's maximum; only player 1 shakes.
DM_PAD_MERGE=1 merges every controller into player 1 as before; DM_KBD_PLAYER=own makes the keyboard player 1 on
its own. One controller, or the keyboard alone, behaves as before. iOS is unchanged: DmGamepad.m still feeds
player 1 and never reports further players.
Rebased onto a678703 (front_mac.m's includes, the Input row of docs/development.md). Checked: host unit tests
pass with the new t_hid (44 checks: slots and reconnects, npads docked and handheld, one- and four-player games,
events, LEDs, the applet); the Mac host builds for Breath of the Wild and Mario Kart 8 Deluxe with no new warning;
hle_hid.c and hle_thread.c pass an iOS SDK syntax check; Hades in a window with the keyboard and DM_KEYS reads
the supported ids (0x10f), and its scripted presses take it past the title. Two controllers were not run here;
the PR's author played Mario Kart 8 Deluxe in 2-player split screen with an Xbox Wireless Controller and a
DUALSHOCK 4, each its own kart, and a controller disconnected and reconnected during play got its slot back.
Co-authored-by: v0lumehi <34629096+v0lumehi@users.noreply.github.com>
Porting a Switch title: agent guide
These pages are for an agent asked to analyse a Switch NSP and port it with the native-execution approach of this repository and d2r-mobile: the game's own aarch64 code runs natively on Apple hardware, a rewriter patches only the instructions Apple's kernel cannot run, the host replaces Horizon system services, and NVN is reimplemented on Metal.
Everything here was learned on Diablo II: Resurrected (SDK ~12, NVN 53, the original target of d2r-mobile) and Super Mario Bros. Wonder (SDK 16.2.0, NVN 55, this repository; its update 1.2.1 uses SDK 16.2.12), then extended by Fire Emblem Engage (Unity, SDK 12.3.7), Metroid Dread (MercurySteam's engine, SDK 11.4.3) 13 Sentinels: Aegis Rim (Vanillaware's engine, SDK 11.4.3, the same sdk and movie module as Dread) Super Mario 3D World + Bowser's Fury (Nintendo EPD's sead / agl engine, SDK 10.4.0, NVN API 53) The Legend of Zelda: Breath of the Wild (EPD's sead / ksys engine, SDK 20.5.22, DT_RELR relocations, update 1.9.0), The Legend of Zelda: Link's Awakening (Grezzo's engine on NintendoWare, SDK 8.2.0, lower-left window origin) Hyrule Warriors: Age of Calamity (Koei Tecmo's KTGL, SDK 9.6.0, RDB archives, shaders as GLSLC outputs) Super Mario Galaxy (a Wii game on NERD's Hagi layer: recompiled PowerPC code, SDK 18.3.5, Vulkan with SPIR-V generated at run time, a 2.9 GB bss), Ace Attorney Investigations Collection (Unity 2022.3 IL2CPP, SDK 17.5.3: the C# file API through the SDK's C library), and the bring-up of Octopath Traveler 0 (Unreal Engine 5, SDK 19.3.13: an AES-encrypted pak, Oodle-compressed shaders that the game's own code decodes on the Mac, its allocator replaced by the host's). Where titles differed, each is given; the next title will differ again, so treat every number below as "measure it, don't assume it".
| Page | Covers |
|---|---|
| 01-extract.md | Keys, NSP → NCA → ExeFS / RomFS, update NSPs, the workspace layout |
| 02-survey.md | Static survey of a new title before touching the host: SDK version, imports vs. host hooks, SVCs, instructions to rewrite, NVN surface, data containers, Ghidra / REA setup |
| 03-bringup.md | Getting the host to boot the game: the run loop, how to read the log, and a catalogue of every failure pattern met so far with its root cause and fix |
| 04-graphics.md | NVN on Metal for a new title: object sizes, shader containers and keys, binding layouts, bindless textures, depth mode, index sizes, swizzle, transient render targets, the diagnostic switches |
| 05-debugging.md | Recipes: crash reports, lldb scripts, Ghidra headless decompilation, objdump, memory growth, render-pass and texture dumps, on-device diagnostics, offline pipeline link checks |
Ground rules
- Bring your own files. Keys, NSPs and anything extracted from them stay in the game's work folder (
$W=<NSP folder>/<title>-work, next to the NSPs on the user's external drive; the home folder is nearly full), never in the repository, never in a commit, never printed. Print key names and lengths only. - Measure, then change. Each fix in this repository started from a concrete observation (a crash address and its decompilation, a census over all shaders, a memory profile). Write the evidence into the code comment next to the fix, the way the existing code does; the next title will need it.
- One repository, one profile per title. nxnative (first called smbw-mobile) started as a copy of d2r-mobile's generic parts. Title- or SDK-specific constants live in the game profile
dm/games/<id>/(dm/games/README.md). That covers program ID, known builds, modules, address-space partition, NVN driver tables, the shader tables and the app identity. The code reads the profile throughgame_profile.h(host) ordm/games/game.py(tools). Behaviour that fits only one title's code is gated by that title's build ID (dm_main_build()), never left on for every title. Some things are still built into the translator: the texture / sampler handle bases and the depth mode (see 04).dmsh_build.pyrefuses a profile whose bases differ from the translator's. - Write code comments in English, and start log lines that mark something unimplemented or wrong with
[RED]. - Test where it runs. The Mac host (
dm/host/dmhost) is the development loop; the iOS app reuses the same host and graphics code. Never claim something works on iOS without running it there.
Checklist for a new title
-
Run
scripts/build_ipa_from_nsp.pyon the title's NSP folder. With no profile for its title ID, it writes<NSP folder>/<title ID>_survey/survey.md:- modules and build IDs, SDK version and components, engine and graphics API markers;
- RomFS containers;
- the rewrite-site census and imports vs. host hooks.
It extracts only the code modules plus a RomFS list for the survey. Unless given
--survey-only, it then writes a provisional profile into<NSP folder>/<title ID>_build/profile/<title ID>/, extracts the game, boots it on the Mac until its heap request when it has virtual address memory (the heap check) and packs a best-effort IPA. That profile is the starting point for step 3: the static keys follow rules checked against every profile, the rest are guesses or defaults (dm/games/README.md); the run-time keys (render_cond,tex_flush_upload,core_preempt, …) are the bring-up's to find. For Mac runs, exportDM_GAMES_DIR=<NSP folder>/<title ID>_build/profileuntil the profile moves intodm/games/. -
Extract base (and update, if in scope) — 01. Finish the survey — 02. Write down: SDK version, NVN API version, module list, imports the host lacks, SVCs, instruction census, NVN loader pattern, shader containers.
-
Add a game profile
dm/games/<title ID>/game.tsv, named after the base game's title ID (start from010015100B514000/game.tsv: identity,buildrows,modules; keep the memory / NVN values until they are measured) and build the host for it withmake -C dm/host GAME=<id>. -
Run the rewriter and check its counts against
insn_census.py. -
Boot on the Mac and iterate on the failure catalogue in 03 until the game reaches its frame loop.
-
Extract and translate the shaders, find the binding layout by census, and get the first frame — 04.
-
Check memory over a minute of running (
footprint, the host's memory report line); fix growth before moving on. -
Input, audio, then the iOS bundle (d2r-mobile's
dm/ios, RomFS inside the app). -
Test on a phone: an unsigned IPA the user sideloads, switches through
env.txt, results throughDocuments/log.txt(05). Several bugs only showed there (the command-buffer byte and the audio buffer size in 03, pipeline link failures in later levels in 04). -
For a game update: extract it over the base game, diff the imports, carry the per-build addresses over, and rebuild the shader tables for both versions (01).