New profile 010005501E68C000 (update 1.0.0.2, Unity 2022.3.17f1 IL2CPP, SDK 17.5.3; the base game an XCI): - Rewriter: two IL2CPP thunks end in an indirect tail call, ldr x18, [x0, #0x18]; ...; br x18 (main+0x1d271bc, +0x204ebec), which asserted as an unknown jump table. When neither table form is found, the last write of x18 is a plain load and the br ends the function, it becomes x16 = guest x18; br x16 (tail_call / site_br_call). Tried only where the rewriter used to stop, so modules it accepted before come out byte-identical. - sdk cut: the AddressRegionManager node area 1 GB -> 62 MB on this build (sdk+0x139468 / +0x1394fc), as for Engage; StandardAllocator::Initialize aborted in nninitStartup without it. - Shaders (unityfs.py, shader_split.py): Unity 2022 keeps each program's parameters as blob entries of their own (m_ParameterBlobIndices; the programs are m_PlayerSubPrograms[tier][].m_BlobIndex), and subprogram version 202012090 (from 2021.2) has no local keyword list. The player's files borrow the unitybuiltinshaders bundle's Shader type tree. 4,951 shaders, 4,950 build (one geometry shader); Engage's layout of driver segments decodes every binding. UnityPy's type trees for 2020.3.18 and 2021.3 have neither field, so Engage reads every entry as before. - hle_fs.c: nnmusl (open / stat / opendir) checks every path with nn::fs::IsPathMounted, GetPathLengthMax, GetUtf16PathLengthMax, GetEntryNameLengthMax and GetUtf16EntryNameLengthMax, which the SDK answered from its empty mount table: File.Exists failed with no nn::fs call, Addressables never found settings.json and the game crashed on a null asset (main+0x31100ec). Answered from the host's mount table with Horizon's 0x300-byte limits. - hle_time.c: clock_gettime(CLOCK_REALTIME) reads the source nntimeStartup selects (sdk+0x8e414), nn::time::GetStandardUserSystemClockCurrentTimespec, which asked the time service; system_clock::now() then called std::terminate after the first dialog. It and the adjustable clock's getter are the host clock now. - Memory: Engage's 5 GB block with a 1 GB application pool. StandardAllocator commits 0.19 GB; with a 2.5 GB pool its reservation and Unity's own pools reached the end of the 4.375 GB alias region after 140 s (probes on VammManager::AllocateAddressRegion / FreeAddressRegion). 25 minutes now peak at +2.81 GB. On the Mac: first-boot settings, title, Investigations 1's Episode 1 into the first investigation, 60 fps, FMOD sound, 25 minutes with no red line, 1.55 GB resident and 1.25 GB of Metal allocations, flat. IPA AceAttorneyInvestigations.ipa (7.0 GB) built from HEAD + these changes; awaits an iPhone test. Also: UNIMPL stubs log once (the seen counter was a byte and wrapped every 256 calls); build_ipa.sh quotes FONT_PY (a Python path with spaces broke the font step); profile_guess.py marks IL2CPP by global-metadata.dat (Unity 2022's main has no il2cpp_ names). Not needed in the end: pull requests #15 (this main's string table is intact) and #16 (nninitStartup sizes no heap with virtual address memory). Much of the bring-up was found first by armyja (GitHub issues #17, #18, #19, pull requests #15, #16). Co-authored-by: armyja <546323405@qq.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) and Ace Attorney Investigations Collection (Unity 2022.3 IL2CPP, SDK 17.5.3: the C# file API through the SDK's C library). 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 (
DM_RULESET=native) and check its counts againstinsn_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).