NX2navi/docs/building.md

Building from source

Windows 10 or later, an x86-64 CPU with SSE4.2, and a GPU with Vulkan 1.3 and VK_EXT_external_memory_host. The default build targets x86-64-v3 (AVX2/FMA); a CPU without them builds with --cpu v2 instead and runs slower (see "Build"). Allow about 60 GB for the work folder. Extraction wants about 55 GB free while it runs and keeps about 35 GB afterwards.

Players who only want to play use the launcher instead: it installs its own build tools, builds the game on their machine and keeps it up to date.

Toolchain

Versions are the ones the build was verified with; newer patch releases are fine.

Tool	Version	Install	Used for
MSYS2 UCRT64	clang/lld 23.1.3	msys2.org installer to C:\msys64, packages below	compiling the generated C and the runtime
Visual Studio Build Tools	2026, C++ workload, Windows SDK 10.0.26100	winget Microsoft.VisualStudio.BuildTools with --add Microsoft.VisualStudio.Workload.VCTools --includeRecommended	the linker .NET NativeAOT calls
.NET SDK	10.0	winget Microsoft.DotNet.SDK.10	the shader translator (nx2navi_xlate.exe)
Vulkan SDK	1.4.363	winget KhronosGroup.VulkanSDK	validation layers, vulkaninfo
uv	0.13	standalone installer from astral.sh	the two Python environments
hactool	1.4.0 @ 1d64a83	.venv\Scripts\python tools\build_hactool.py, see below	NCA and update extraction

MSYS2 packages, after pacman -Syuu (run it twice; the first pass updates the core and exits):

pacman -S --needed --noconfirm mingw-w64-ucrt-x86_64-{clang,lld,ninja,gcc,make,pkgconf,sdl3,opus,libvpx,dav1d,zstd,vulkan-devel,\
vulkan-memory-allocator,vulkan-validation-layers,shaderc,spirv-tools} base-devel git unzip

ffmpeg from MSYS2 is a GPLv3 build and is never linked; the movies go through libvpx.

PATH:

• Add C:\Program Files (x86)\Microsoft Visual Studio\Installer to the user PATH: NativeAOT needs vswhere.exe, or the publish fails at the link step (MSB3073).
• Another cmake or ninja earlier on PATH (a 32-bit winlibs MinGW, for example) is picked up by accident. The build scripts call Ninja from C:\msys64\ucrt64\bin themselves; from a shell, put C:\msys64\ucrt64\bin first.

hactool

tools/build_hactool.py fetches hactool at 1d64a83 into toolchain\src\hactool, applies the three patches in tools/hactool/ and builds a static toolchain\hactool\hactool.exe with MSYS2 UCRT64 gcc (a few seconds):

• portable.patch: the changes a portable Windows build needs, the MNG_TITLE_KEYS variable and the two BKTR fixes in nca.c for the subsection table padding and the subsection layout of newer cumulative updates;
• unicode.patch: a manifest with <activeCodePage>UTF-8</activeCodePage>, so paths under a non-ASCII user profile reach it intact;
• mbedtls-asm-clobbers.patch: the memory and cc clobbers the bundled mbedtls 2.6.1's x86-64 multiply asm lacks. Without them a clang build (the Linux release) fails every RSA signature check and the update merge stops.

hactool reads -k <prod.keys>; MSYS2 shells set HOME, which hides its default key location, so pass -k there.

Build

From the repository root, in PowerShell. Every step that depends on the game version takes it as <ver>: v143 for 1.4.3, v121 for 1.2.1 or v110 for 1.1.0. The tools default to v121 when --version is left out. Saves load on any of them.

1. Python environments (once). .venv runs the lifter and the build; .venv-py314 runs the extraction scripts, which need the stdlib compression.zstd of Python 3.14:

   uv venv --python 3.12 .venv
   uv pip install --python .venv/Scripts/python.exe -r tools/requirements.txt
   uv venv --python 3.14 .venv-py314
   uv pip install --python .venv-py314/Scripts/python.exe -r tools/requirements-py314.txt
   

2. Copy config.example.toml to config.local.toml and set the paths to your base game, the update and your console's keys file. config.local.toml is ignored by git. The tools read the keys file themselves.

3. Extract and verify. This writes build\extracted\v0 (1.0.0) and build\extracted\<ver> for each update in updates, identified by its hash; a hash mismatch stops the run. With another [work] dir in config.local.toml, extracted goes there instead, and build_game.py reads the ExeFS and RomFS from there:

   .venv-py314\Scripts\python tools\extract.py
   

4. Shader translator (no game files; again after a change to its sources, and tools\make_release.py stops on an older one). This publishes build\xlate\nx2navi_xlate.exe:

   .venv\Scripts\python tools\build_xlate.py
   

5. Lift the modules to C, write the RomFS overlay (the frame-rate fix), then compile and link build\<ver>\nx2navi.exe:

   .venv\Scripts\python recomp\gen.py --exefs build\extracted\<ver>\exefs --out generated\<ver> --patches recomp\patches-<ver>.txt
   .venv-py314\Scripts\python tools\make_romfs_patches.py --version <ver>
   .venv\Scripts\python tools\build_game.py --version <ver>
   

   The menu's font comes into runtime/ui/menu.cpp with #embed; for a compiler without it (before clang 19, which a Linux build with the distribution's compiler can meet) the same step writes the font's bytes as runtime/ui/roboto_ttf.h (git ignores it), which menu.cpp then includes. The runtime's own shaders (upscaling, HDR, texture decode and the like) are in the repository as source only: GLSL and SPIR-V assembly in runtime\shaders\, and two small ones assembled by tools\make_dlaa_mask.py and tools\make_mvobj_fs.py. build_game.py compiles them into runtime\<name>_spv.h (git ignores these) before it compiles the runtime, with glslc, spirv-as and spirv-val from the shaderc and spirv-tools packages above, and again whenever a source changed. python tools\build_shaders.py does that step alone; --check only reports the headers that are missing or stale.

   --cpu v2 targets x86-64-v2 (SSE4.2, no AVX2/FMA) for older CPUs; the default v3 needs AVX2. The v2 build links runtime/fma.c, a correctly rounded software fma the FP lowering needs, and runs slower. Inline assembly, target attributes and intrinsics are not bound by -march, so a v2 build runs tools/check_isa.py over the runtime objects before it links: any AVX, BMI or other instruction above x86-64-v2 outside a function listed there as dispatched by a runtime CPU check stops the build. python tests\check_isa_test.py builds the files with such functions both ways and checks that they pass.

   gen.py sizes its emit pool from the CPU count and the free memory; --jobs N sets it, and so does the environment variable NX2NAVI_LIFT_JOBS=N, which the installer's lift step honours too (it has no --jobs). When a worker runs out of memory, the pool restarts with half the workers (emit: out of memory with N workers, retrying with M), down to one; only an out-of-memory error with one worker fails the step.

   Lifting takes about 15 s, a clean compile about 200 s on 24 threads; later builds recompile only what changed. A compiler cache in front of clang shortens it further: with SCCACHE set to an sccache executable, build_game.py writes it into the ninja file ahead of cc, and every lift rewrites the generated chunks with the same contents, so a second build of the same version hits all of their objects:

   $env:SCCACHE = "path\to\sccache.exe"
   .venv\Scripts\python tools\build_game.py --version <ver>
   

   --patches builds in the frame-rate, resolution and other patch sets, switchable at run time. The link copies SDL3.dll, libiconv-2.dll and libopus-0.dll next to the exe. For Xbox button prompts, run make_romfs_patches.py twice more, with --prompts xbox and --prompts xbox-label: they write build\<ver>\romfs-patches-xbox and romfs-patches-xbox-label (controls.md, "Xbox button prompts"), which build_game.py copies next to nx2navi.exe like romfs-patches. --prompts pc writes romfs-patches-pc, the keyboard and mouse prompts (controls.md, "PC button prompts").

6. Prepare the shaders (once per build folder and translator). It needs refs\MacNativeGames (tools\fetch_refs.sh) for the shared shader list:

   .venv-py314\Scripts\python tools\prepare_shaders.py build\<ver> --version <ver>
   

   Without this step the first launch compiles shaders and pipelines during play and stutters until the caches fill. The AMD driver keeps its pipeline cache per exe path and holds a limited amount: preparing another build folder can evict this one's. nx2navi.exe --warm-shaders rebuilds it from the shader cache. A driver update empties the driver's cache too, and a change to what a stage library is built with gives every library another entry in it. So an update that carries the prepared shaders over runs --warm-shaders (tools/make_game.py warm_driver_cache: seconds while the libraries are there, minutes when they are not), and the game itself checks at every start: it builds a sample of the prepared fragment libraries and, when their median time says the cache is cold, builds the whole prepared list into the driver's cache again on idle-priority threads while it runs (runtime/vk_pipeline.c lw_start, NX2NAVI_LIB_WARM; shader-warm.txt next to the caches says where that stands). With the cache cold every pipeline a draw first needs compiles in play: on an RX 7900 XT a library took 93 ms (vertex) and 242 ms (fragment) on average against 0.3 and 0.6 ms from the cache, and a first walk through a village skipped 11,180 draws and made 94 draws wait 5.5 s in all, against 1,605 skipped (1,473 of them in the scene's first frames) and 60 ms of waits with the cache warm. A frame that still lacks draws when it is presented is not shown: the previous picture stays on screen (runtime/vk_backend.c frame_hold, NX2NAVI_FRAME_HOLD_MS, an allowance of 120 ms that fills again at an eighth of the clock's rate). On a first walk through a village with nothing recorded, 21 of the 23 such frames were held back; in a player's session a hit by a boulder had shown one black frame, its lighting pass skipped after 50 ms. When the driver's shader compiler crashes on a variant (NVIDIA 615.78.08 on an RTX 5080 does, issue #30), prepare_shaders.py runs the driver step again with --warm-shaders, up to three times, without the variants the driver was building at the crash. shader-prepare-skip.txt next to the exe lists them with the GPU and driver version; they build at their first draw instead, another driver version builds them again, and so does deleting the file.

   What this step leaves for play, and the shared pipeline list. The step translates every shader's default variant and the shader list's variants and builds each one's stage library or compute pipeline. A whole graphics pipeline is built ahead at the start of a game folder that has drawn it before (pipeline-keys.bin) or whose release listed it (below); a pipeline met for the first time is linked from its stage libraries in 2 to 8 ms, of which its first draw waits 3 (pipe_link_draw_ms, from the pipeline's first miss; runtime/vk_exec_draw.c link_budget), except a mesh pipeline, which has no libraries and compiles whole (0.2 to 1.1 s, its draws left out of the picture meanwhile), and many of them on a first visit add up to hitches. tools/pipeline_list.py merge folds the pipeline-keys.bin and shader-answers.bin of game folders that were played, and lists made before, into a pipeline list, with the compute variants those folders dispatched (no pipeline record names a compute shader, and a variant the shader list lacks is translated on the frame that first dispatches it); prepare_shaders.py reads it from tools\data\pipeline_list.bin (data\pipeline_list.bin in a release folder, or --pipeline-list), adds the shader variants it names to the seed and writes its records next to the game as seed-pipeline-keys.bin, and --prepare-shaders builds every one of them into the pipeline cache and the driver's (runtime/vk_pipeline.c seed_pipelines; NX2NAVI_PREPARE_PIPELINES=mesh builds only the mesh pipelines). Every start then counts the list as known pipelines beside the folder's own and builds them before play, from those caches (keys_open_seed; pipe_seed = 0 in nx2navi.ini leaves the list out). --warm-shaders builds them again, and nx2navi.exe --prepare-pipelines does that step alone. The list is derived from game data: it is not in the repository (tools/check_content.py refuses it), and a kit, a launcher release or an installer release takes one with --pipeline-list (tools/make_kit.py, make_launcher.py, make_release.py). A list belongs to the record layout of the runtime that wrote it; another runtime says so and builds nothing from it. python tests\pipeline_list_test.py checks the tool on made-up folders.

   What a game folder's shader cache holds can be checked without the game: python tools\validate_shader_cache.py <game folder>\shader-cache reads every translated shader from the pack and the loose files, applies the checks the game makes when it loads one (those that fail are translated again at their next use) and runs spirv-val on the rest; --every N samples, --out FILE lists the failed ones. It writes nothing to the cache. python tests\validate_shader_cache_test.py checks the tool on a made-up cache.

7. Run. The game keeps running when its window loses the focus (assume_focus = 1 in nx2navi.ini, the default; the Game tab switches it). With 0 it pauses, as it does on the Switch when Home is pressed.

   build\<ver>\nx2navi.exe
   

Settings live in nx2navi.ini next to nx2navi.exe (nx2navi.ini.example lists them). Saves go to build\profile for v121 and build\profile-<ver> for other versions (build_game.py --profile changes it).

Portable folder

.venv\Scripts\python tools\package_build.py --version <ver> writes build\<ver>-portable, which runs on another of your machines without MSYS2, Python or .NET. romfs.bin stays out unless you pass --with-romfs; otherwise put it in romfs\ next to the exe or point NX2NAVI_ROMFS at its folder. Run nx2navi.exe --prepare-shaders once in the copied folder. The folder holds code and data derived from your game: for your own machines only.

Profile-guided build

A build with an execution profile compiles the lifted code at -O2 with the counts of a play session, and the runtime with them too: hot paths laid out straight, hot calls inlined, functions that never ran compiled for size. On 1.4.3 the fight bench ran 12-15% faster per frame and a fight outside the training about 6%. Game 1.1.1 has no profile yet and no measurement: "Training a profile for 1.1.1" below is the session that makes both.

Game 1.1.1 is built by tools/make_game.py, on the player's PC through the launcher. It compiles with data\pgo-v111.profdata of its kit (app\<version>\data\ of a launcher release, which make_launcher.py --pgo <file> puts there and builds the prebuilt runtime with; build\pgo\ in a source checkout) and says so in the compile step's log. The profile is left out, and the build is the one a kit without a profile makes (the lifted code at -O1), when:

• the kit has no profile, or NX2NAVI_PGO=off is in the environment (make_game.py --pgo off);
• its record (pgo-v111.json) is missing or names another recomp/ than the kit's (make_game.py pgo_record). Functions are matched by name and control-flow hash, so a function whose C changed loses its counts without a warning; the record holds recomp/ by content (the lifter's .py files and patches-v111.txt), and any change there means a new training;
• the compiler cannot read the file: one trial compile at the start of the compile step, by each compiler that will read it (pgo_trial). The log then names what the compiler said.

A profile is written by the llvm-profdata of one LLVM release and read by the clang of the build tools, which a release pins in toolchain.lock.json (clang 23.1.5 in 0.9.2). The same release or a newer clang reads it; an older one than the file's format refuses it with an error in every compile, which is what the trial compile is for. Train with the compiler the release pins: then the instrumented game, the merge and the players' build are one LLVM release.

An instrumented build links the compiler's profile runtime, which MSYS2 packs apart from clang and neither C:\msys64 (after the packages above) nor the launcher's build tools hold: the package mingw-w64-ucrt-x86_64-compiler-rt in the version of the clang it goes with, unpacked into the msys64 folder of those build tools (pacman -S for C:\msys64; for the launcher's toolchain\msys64, the package file from the MSYS2 repository unpacked there). make_game.py links a test program first and names the package when it is not there (pgo_gen_check). The merge needs llvm-profdata of the same LLVM release: MSYS2's mingw-w64-ucrt-x86_64-llvm-tools, or the bin\ of an LLVM installation of that release.

Training a profile for 1.1.1

<game> is a game folder make_game.py built (the launcher's game\, or one built from a checkout), <ucrt64> the UCRT64 folder of the build tools with the profile runtime, python a Python with numpy and lz4 (.venv). A checkout also needs the shader translator in build\xlate (step 4 of "Build"). Run every step from one commit with a clean recomp/.

1. Measure the build without a profile (step 6) while the game folder still holds it.

2. Build the instrumented game into the same folder. In a folder this checkout built only the compile step runs: the lifted code at -O2, every runtime file (the prebuilt runtime counts nothing), and the link.

   python tools\make_game.py --rebuild --out <game> --msys <ucrt64> --pgo gen
   

   From the launcher instead: start NX2navi.exe with NX2NAVI_PGO=gen in its environment and choose Rebuild the Game; the launcher hands the variable on to its build.

3. Delete <game>\pgo\*.profraw left from an earlier instrumented build, then play: start <game>\ocarina.exe (or Play in the launcher) and play for 20 to 30 minutes with the settings players have by default. Cover the title screen and the file select, Kokiri Forest, Hyrule Field on foot and on horseback, a town, a dungeon with fights and a boss, the menus and the map, a cutscene, a save and several area changes. What is not played counts as never run and is compiled for size. The game is slower than a normal build. Several sessions add up.

4. The game adds its counts to <game>\pgo\default_<id>.profraw every minute and when it ends (runtime/platform/win32.c pgo_flush_thread, plat_exit), so a crash loses at most a minute; look for the file after the first minute of play. <game>\pgo\training.json names the recomp/ and the compiler the game was built from. The game's own runs inside a build (the shader preparation) count into <game>\build-cache\pgo-build\ and are not merged.

5. Merge, with the llvm-profdata of the LLVM release that built the game:

   python tools\pgo.py merge <game> --version v111 --toolchain <folder with bin\llvm-profdata.exe>
   

   This writes build\pgo\pgo-v111.profdata and its record pgo-v111.json, and stops when the checkout's recomp/ is not the one the game was built from. Then build with it; the log must say built with the execution profile pgo-v111.profdata, or it says why not:

   python tools\make_game.py --rebuild --out <game> --msys <ucrt64>
   

6. Compare the two builds with the runtime's own profiler (runtime/prof.h, runtime/prof_win.c), in the same place from the same save, the camera left alone, with the same settings. In <game>\nx2navi.ini (or as NX2NAVI_TRACE, NX2NAVI_PROFILE and NX2NAVI_PROFILE_FRAMES in the environment):

   trace = perf
   profile = <game>\logs\before.prof
   profile_frames = 7200-10800
   

   profile (NX2NAVI_PROFILE) samples every thread each millisecond; profile_frames limits that to the presented frames 7200 to 10800, the third minute at 60 frames a second, and the profile is written when the window ends, so be in place before it starts. Use after.prof for the second build. Then, for each, before the next build replaces ocarina.map (the report names the functions from the map of the build that was sampled):

   python tools\prof_report.py <game>\logs\before.prof <game>\build-cache\ocarina.map
   python tools\perf_summary.py <game>\logs\nx2navi.log 7200 10800
   

   At the default 60 frames a second both builds draw the same frames, so the sample counts of guest (f_*) (the lifted code) and runtime host (exe) in the report are processor time for the same work: the profile's gain is how far they fall. For the frame time itself set fps_limit = unlimited and compare the interval avg of the perf: lines in a place the processor bounds, such as a town at a low render_scale. Measure a place that was in the training and one that was not.

The profile and the raw counts are derived from the game's code: they stay under build\ and in the game folder, tools/check_content.py refuses them in a commit, and a release carries the profile only as make_launcher.py --pgo puts it there. python tests\pgo_build_test.py checks which flags a build takes for a kit with and without a profile, for a record of another tree and for a profile the compiler refuses, with a stand-in for the compiler.

The other game versions build with tools/build_game.py: --pgo gen with an llvm-mingw toolchain makes the instrumented nx2navi.exe, which writes <out>\pgo\*.profraw; tools\pgo.py merge <out> --version <ver> merges them, and --pgo build\pgo\pgo-<ver>.profdata compiles with the result. make_release.py ships every profile of build\pgo in data\, where the installer's build takes the one of its update, and warns when a record names another recomp/ tree than the one released.

Linux (in progress)

The runtime builds and runs on x86-64 Linux with a window, input and menu on SDL3 (*_sdl.c) in place of the Win32 files (*_win.c); runtime/platform/linux.c implements platform.h. Status: the selftest and the probes pass; 1.2.1 plays at 60 fps on RADV (RX 7800 XT) and NVIDIA (RTX 3060); 1.4.3 builds, probes and plays on RADV (RX 6600, and the Vega 7 of a Ryzen 5 4600G at about 34 fps). Long play sessions and the Steam Deck itself are not verified yet.

Requirements:

• Linux 6.7 or later: the write watch uses userfaultfd write protection with PAGEMAP_SCAN. SteamOS 3.8 qualifies.

• A Vulkan 1.3 driver with VK_EXT_external_memory_host (RADV, NVIDIA).

• Packages on Arch:

  pacman -S --needed clang lld ninja make sdl3 opus libvpx dav1d zstd vulkan-headers vulkan-icd-loader \
      vulkan-validation-layers shaderc spirv-tools dotnet-sdk uv git
  

  Vulkan Memory Allocator is a single header (AUR vulkan-memory-allocator). Without it, build_game.py fetches the version the Windows release pins (3.4.0) into toolchain/vma/ on first use and checks its hash. The Vulkan headers must be release 363 (1.4.363, the one MSYS2 supplies on Windows) or newer: the runtime names extensions older headers lack. Where the system's are older, build_game.py and make_game.py fetch that release into toolchain/vulkan-headers/ on first use, check its hash and put it ahead of the system's (tools/vulkan_pin.py, build_game.py vulkan_include).

The steps are the Windows ones with POSIX paths: .venv/bin/python in place of .venv\Scripts\python, and nx2navi in place of nx2navi.exe. build_game.py takes clang, lld and Ninja from PATH (or the ones in <dir>/bin with --toolchain <dir>) and links against the system libraries, with libstdc++ static and an $ORIGIN rpath; build_hactool.py builds hactool with make. tools/prepare_shaders.py reads the shader list from refs/MacNativeGames at origin/HEAD, which must be the pinned commit with its history (the list format changed later).

The probes open a window, so from an SSH session they need the desktop session's display, or they stop at gpu 0 skipped: no graphics+compute+present queue family: on Wayland XDG_RUNTIME_DIR=/run/user/$(id -u) WAYLAND_DISPLAY=wayland-1 SDL_VIDEODRIVER=wayland (the socket name is in $XDG_RUNTIME_DIR), on X11 DISPLAY=:0.

NVIDIA's Linux driver compiles into a disk cache of its own. A process adds at most __GL_SHADER_DISK_CACHE_SIZE to it (1 GiB by default; at a start the files after the first are deleted while the folder is over that size), and the default folder, ~/.cache/nvidia, is shared with every program. --prepare-shaders of game 1.1.1 builds 42,142 variants, about 1.5 GB: on the default limit about 30,700 of them were stored and the rest compiled again at their first draw in play. runtime/vk_device.c therefore points __GL_SHADER_DISK_CACHE_PATH at nvidia-cache beside ocarina and the size at 8 GiB, each unless the environment sets it, as it does MESA_SHADER_CACHE_DIR for RADV, and only while NVIDIA's kernel driver is loaded (/proc/driver/nvidia/version). The driver does not make that folder and caches nothing in a folder it cannot write, so the game makes it, and when it cannot make or write it sets neither variable. A game run sets them in main before any of its threads starts, since a thread can load the Vulkan driver before the instance is made. The folder can be deleted; ocarina --warm-shaders fills it again.

Memory: on Windows the GPU imports guest memory and GetWriteWatch tracks the CPU's writes to it. On Linux, re-protecting imported memory invalidates the driver's userptr buffer on every submit (about 1.3 ms per 16 MiB on amdgpu), and importing pins the pages, which drops their write protection. Where guest memory cannot be imported as dma-bufs (below), each CPU-visible pool therefore gets a host-visible copy (shadow storage, runtime/vk_memory.c): the pages the CPU wrote go in before each submit, and the GPU's writes come back at its fence. Pages both sides write keep a base copy, so each direction moves only its own bytes; a VRAM mirror's write-back merge marks the pages it changed, and only those are compared at the fence; a lookup that reads guest memory itself (the uniform snapshot, vk_mem_lookup) does not queue its pool for the copy-in. In Kokiri Forest (1.1.1, RTX 4090) that costs about 1 ms a frame (copy-in 0.5 ms, write-back 0.6 ms), and the copies hold about 5 GB. The GPU's bytes reach guest memory in the fence's completion callback, later than an import's, so the wait after a frame's first submission covers the write-backs there (runtime/vk_sync.c, "the executed timeline"): the game rewrites what those passes wrote without a fence, and a write-back that landed after the rewrite left the GPU adding light onto its own last output, the whole scene brighter for a frame. NX2NAVI_SHADOW=1 turns it on under Windows too. The Steam Deck's RADV has VK_EXT_external_memory_host as well: the shadow copies are chosen for the measured cost above, not for a missing extension. NVIDIA's own driver on Linux imports instead (NX2NAVI_SHADOW=1 brings the copies back): it imports guest memory without that cost, so there the copies are only the slower path. In Kokiri Forest on 0.7.1 (RTX 4090, driver 615.78), imports with VRAM mirrors ran at 51.9 frames a second and the copies at 27.4; on that version the copies also flickered between two looks almost every frame, which the wait for the write-backs under shadow storage (vk_sync_exec_wait) has since addressed.

On Linux the pools are imports after all where the system allows dma-bufs of guest memory (runtime/platform/linux.c, "Guest memory as a memfd's"; runtime/vk_memory.c, "dma-buf imports"). The watched reservations are then shared mappings of one memfd, /dev/udmabuf makes dma-bufs of page ranges of it, and the device imports those (VK_KHR_external_memory_fd, VK_EXT_external_memory_dma_buf). A dma-buf pins its pages once and is not tied to the process's page tables, so the write watch and the freezes leave the GPU's mapping alone, and nothing is copied. RADV puts every imported memory object into every submission (about 0.6 us each), and the game keeps over 4,000 pools, so pools share their imports: guest addresses are cut into spans of 64 MiB (NX2NAVI_DMABUF_MB), and a pool is a buffer bound into its span's memory at its offset. A new span is cut back at the spans already there, so spans overlap only where a pool itself lies across an older span's edge: amdgpu counts every span's pages in its GTT use, an overlap twice. A span pins all of its pages, those the game never touched included, until some frames after its last pool is gone. It takes /dev/udmabuf readable and writable by the player (recent systemd gives it to the logged-in user with its uaccess tag; elsewhere it is often root and group kvm only), udmabuf's size_limit_mb (/sys/module/udmabuf/parameters/size_limit_mb) at 1024 or more, since the largest pools need about 300 MiB in one dma-buf (where it is lower, udmabuf.size_limit_mb=1024 on the kernel command line raises it), a device with both extensions, and NVIDIA's kernel module not loaded: NVIDIA's own driver imports host pointers without amdgpu's cost, as above. A start-up probe imports one page of guest memory as the pools will be; where anything is missing or refused, the pools keep their shadow copies and the log says why (mem: dma-buf imports off, mem: guest memory is not a memfd's). NX2NAVI_DMABUF=0 keeps the copies, and NX2NAVI_DMABUF=1 makes guest memory a memfd's even where NVIDIA's module is loaded; both only from the environment, since the reservations are made before nx2navi.ini is read. NX2NAVI_SHADOW=1 still forces the copies. In Kokiri Forest (1.1.1, RX 6800 XT, Mesa 26.2) the imports ran at 60.7 frames a second and the copies at 40.3, in Hyrule Field at 55.7 and 42.4; the spans then held 8.0 to 9.6 GiB, and amdgpu counted 8.6 to 10.1 GiB of its 15.8 GiB host heap in use, against 5.2 to 5.6 GiB with the copies, which are memory of their own beside guest memory.

The device address table (runtime/vk_gpa.c) names a pool's shadow copy as it names an import, so shaders follow guest pointers into either. A shader that reads through the table resolves nothing, so the pool it reaches is not queued for the copy-in: a guest submission whose record binds the table (vk_exec_draw.c ssbo_info) brings the shadow of every pool in the table up to date with the pages the CPU wrote, once, before the first part recorded after the binding is submitted, and queues the same pages for those pools' VRAM mirrors (vk_memory.c vk_mem_shadow_sync). That copies the written pages of every CPU-visible pool once in each such guest submission, which the cost above does not include. What a shader stores through the table lands in the shadow copy and in the pool's VRAM mirror, and no binding names it, so nothing notes it as a GPU write: it does not come back to guest memory, and the next whole copy-in of its page (the CPU rewrites other words of the same records) puts guest memory's stale bytes back over it in both copies. In the runs measured so far that copy-in always came before the frame's stores, which does no harm. NX2NAVI_SHADOW_TABLE_STORES=1 keeps the stores instead: the copy-ins then keep a hash of each page they write, a page whose shadow no longer matches its hash was stored into, keeps a base copy from then on like a page with a noted GPU write, and has its stores written back to guest memory at the fence of every submission that uses the table. It is off by default (runtime/vk_memory.c, "Pages a shader stores into", says why). NX2NAVI_SHADOW_CHECK=1 logs every 60 frames how often a copy-in overwrote such a store and for which pools, how many write-backs landed on pages the CPU had written since their copy-in, and what the copy-ins cost and where they went. --probe-vkmem checks the sync: the shadow of a pool that is never bound must hold 0x13579BDF, keep it through a plain CPU write and a guest submission that does not bind the table, and hold the written 0x2468ACE0 after one that does; and with NX2NAVI_SHADOW_TABLE_STORES=1 the store: a GPU write into a shadow page that nothing notes must survive the CPU's writes of that page and reach guest memory. On Linux, run it for each backing (with NX2NAVI_DMABUF=1 and NX2NAVI_SHADOW=0 the pools are dma-buf imports, with NX2NAVI_DMABUF=0 and NX2NAVI_SHADOW=0 host-pointer imports):

for dmabuf in 0 1; do for shadow in 0 1; do for memory in import mirror; do
    NX2NAVI_DMABUF=$dmabuf NX2NAVI_GPA=1 NX2NAVI_SHADOW=$shadow NX2NAVI_MEMORY=$memory ./ocarina --probe-vkmem
done; done; done

The Deck's GPU (Van Gogh) has no native ASTC, so its textures go through the compute decoder (runtime/vk_astc.c, NX2NAVI_ASTC) as on desktop AMD GPUs without it; frame times measured there include it.

Checks

Before a commit:

• python tools/check_content.py --staged: nothing game-derived and no compiled shader is staged. CI runs the same check; git config core.hooksPath .githooks runs it before each local commit.
• build\<ver>\nx2navi.exe --selftest: layout, dispatch table and host-function registry, without game files.
• python tools\check_platform.py after a runtime change outside runtime/platform/: no shared file uses Win32 outside a branch that only a Windows build compiles (#ifdef _WIN32, the #else of #ifndef _WIN32). python tests\check_platform_test.py checks the scanner itself on made-up files.

A change to the in-game menu's look (runtime/ui/menu_skin.cpp, option_rows.cpp, perf_panel.cpp) can be looked at without game files: python tools/menu_preview.py builds the menu's own drawing code with the host's clang++ and writes the Screen tab, the full performance overlay and the boot screen to build/menu-preview/ (menu.png, overlay.png, boot.png; a stand-in font, and the window's plain border in place of the game's ornamented frame). With --romfs <extracted RomFS folder> it draws the game's interface textures as the game does, and tools/ui_textures.py <folder> lists the textures there and dumps those matching --match to build/ui-textures/; both decode the game's files, so they run with .venv-py314\Scripts\python (compression.zstd and numpy). What they write is decoded game data: keep it under build/.

A change to the shared save (runtime/save_zip.c, runtime/save_share.c, the save import in runtime/fs_host.c) passes python tests\save_zip_check.py and python tests\save_share_check.py. The first builds save_zip.c alone and checks its deflate, inflate, zip writer and reader against Python's zlib and zipfile both ways, and that the launcher imports a zip it wrote. The second builds fs_host.c and save_share.c with the rest of the runtime stubbed and runs each step as a start of the game on a profile it makes: the export, an import from a zip the launcher exported, its backup and swap at the next start, the zips it refuses and Cancel. No game files.

A change to the step Ocarina is given each frame (runtime/frame_rate.c ocarina_step), or to the whole numbers the game's counters get out of it (whole_take, frame_rate_day_host, frame_rate_water_host, frame_rate_sim_host), passes python tests\frame_step_check.py, which builds frame_rate.c with the rest of the runtime stubbed and feeds it display times: a held 60 fps limit gives exactly one frame every frame, a 240 fps limit never less than a quarter frame, uneven frame times one steady step, and game time follows the clock. While RivaTuner Statistics Server holds the limit the pacer keeps the 240 ceiling, the limit's own period once no host present went out for 200 ms, and a movie's rate. It calls the two hooks as their patch sites do: at 144 fps each of 64 water objects gets its ripple steps and the day its seconds, at 120, 144 and 240 fps the water managers and floors of the set owater get 60 fixed steps a second with only s0 changed, and a step of one frame gives what the game computes. It also checks that each of those sites in recomp/patches-v111.txt ends in one bl to its page slot, and runs the physics solver step count's words of the original and the sets osolver and osolverfull (physics_steps 0, 1 and 2), lifted as the generator lifts them: the game's 4 and 8 at 60 and 30 fps for all three, rounded up by osolver and at least 4 every update by osolverfull above 60 fps. For the set ofollow (floor_carry) it checks the two words of each of the three floor-carry gates and runs the gate's compare with the game's words and the set's: the page's cut is 100 at 60 and 30 fps, and from 90 to 240 fps the set cuts a floor's velocity at the time scales where the game cuts it at 60 fps and nowhere else. No game files.

A change to how the frame limit goes to RivaTuner Statistics Server (runtime/rtss_limit.c, runtime/rtss_decide.h) passes python tests\rtss_limit_check.py. It builds rtss_decide.h alone and checks its reader of RTSS's shared memory against a fake RTSSSharedMemoryV2 (a bad header, short entries, an entry past the memory or past the 4096th find nothing; the flags and the period where RTSS keeps them) and the worker's decisions poll by poll against a fake profile and a fake RTSS clock: RTSS's injection delay through listed with no API, the profile not read yet and no period measured, RTSS quitting and coming back, a read-only profile, a refused limit, the frame count rule (1.05 times the limit over three new periods, a frozen period never counted), an RTSS that lists the game and never shows its hold (given up after 30 s, a minimised window not counted), no picture going out, kept-out wants and their reasons, a want that must stay two polls and low latency switching at every poll, a movie at 144, 60 and 40, a closed run, a hooks library that does not load, and two limiters. It also checks the pacer's period beside RTSS (rtss_pace_period), the limit's rounding without a denominator, and the state file rtss-profile.txt: its lines, its rewrite and what a start does with a line a run that did not close left, the value written before the newest one included. Statically, a crash and a fatal error (main.c crash_handler, dispatch.c fatal_end) go through rtss_limit_crash. On Windows it also builds the real rtss_limit.c against a fake RTSS (its registry key, hooks library, profile files and shared memory) and runs each scenario in a process of its own, among them a want after the exit's restore and one the worker read before it, a worker polling without pause while the want switches, the registry and file calls a present must not make, and a run killed while RTSS held its limit followed by the next start, each in a process of its own (a next start with a limit, with frame generation on and with NX2NAVI_RTSS=0, and a run killed inside the save of its second limit), put backs that do not land, a state file that does not read, and a crash on RTSS's own thread with no line in the file. No GPU, no RTSS, no game files.

A change to how the mixer applies volumes (runtime/audio_mixer.c accumulate_ramp, the voice and splitter paths of audio_mixer_render) or to what it owes the device after a stall (ring_pull, audio_mixer_owed) passes python tests\audio_mixer_check.py, which builds audio_mixer.c with the rest of the runtime stubbed. It mixes voices of one constant sample, so a mix buffer shows the gain sample by sample: a volume stepped from 0 to 1 rises in equal steps across the next 5 ms frame and holds after it, for a voice into a mix, a voice into a splitter destination and a submix into one; a voice that starts, was silent in the frame before or was moved to another mix, a destination that is new or was moved, and the first frame after the renderer starts take the new volume at once; NX2NAVI_AUDIO_RAMP=0 applies every volume at once. It also makes the device's requests by hand: the silence of an underrun, up to the prefill's return, is owed in whole render frames, which are rendered and not queued; the silence before the first prefill and across a stop is not owed, and more than 3 seconds of it is given up. The render thread's own timing (runtime/audren.c render_thread) is not built by it. No game files and no audio device.

A change to the sprint button (runtime/sprint.c, the set sprint of recomp/patches-v111.txt, its call in runtime/ov_input.c npad_states) passes python tests\sprint_check.py, which builds sprint.c with the rest of the runtime stubbed and plays frames against a stand-in Link: toggle and hold on each kind of button, the states that keep and end a sprint, ZL, the button kept from the game only during play (the bottom button only while Link moves) and a Link the player does not control, and the set switched off with the button off but never over a start that kept it off. No game files.

A change to the text speed (runtime/text_speed.c, the set text_speed of recomp/patches-v111.txt, its call in runtime/ov_input.c npad_states) passes python tests\text_speed_check.py, which lifts the set's replacement words with recomp/lifter.py and runs them with text_speed.c against a stand-in message window and typewriter: the page words each setting writes and the set it switches, the skip site's decide bit and typewriter word for a message the player may skip and one the game keeps from skipping, the speed site's factor for that typewriter and no other, the registers and flags both sites leave alone, and a start that kept the set off. No game files.

A change to the mouse camera (runtime/mouse_direct.c, the mouse path of runtime/input.c, the set mouse_direct of recomp/patches-v111.txt or patches-v143.txt) passes python tests\mouse_direct_check.py --cc <clang> --deps <ucrt64>\include, which builds mouse_direct.c, and input.c with --deps, with the rest of the runtime stubbed and calls the camera hooks as their patch sites do, for each game version: the registers a site hands over and gets back, the same turn for the same mouse distance at every frame rate and stick camera speed, a single count, the idle bit, the pause after a camera reset, the capture and the mode, and scripted mouse counts. No game files.

A change to which waits a signalled event or an ended thread wakes (runtime/kernel.c wake_sync_waiters, the WaitSynchronization service) passes python tests\sync_wake_check.py, which builds kernel.c with the platform layer and the rest of the runtime stubbed and runs guest threads whose entries are host functions: a signal wakes the waits on its event and leaves the others asleep, a wait on several handles reports the right one, a thread's end ends the wait on it, timed waits keep their time, a cancel ends any wait, and 4,000 signals to eight looping waiters are each seen. It runs a second time with NX2NAVI_SYNC_WAKE_ALL=1. No game files.

A change to what a host thread gives back when it ends (runtime/platform/win32.c thread_main, plat_thread_end_hook) passes python tests\thread_end_check.py, which builds the platform layer alone: 416 threads sleep, read a file and end, half joined and half detached; the end hook runs once on each, and on Windows the process holds as many handles afterwards as before (each thread's sleep timer and read event are closed). No game files.

A change to the census of the process's handles by kind (runtime/platform/win32.c plat_handle_census, which NX2NAVI_HANDLE_CENSUS logs) passes python tests\handle_census_check.py, which builds the platform layer alone: 20 events and 5 sections made show as Event +20 and Section +5, the total stays within 2 of the process's handle count, the figures go back once they are closed, and the kinds past the room given are summed in the last entry. Windows only. No game files.

A file a detached thread writes piece by piece (the flight recorder's dump, runtime/flight.c dump_main) goes through runtime/part_file.h: it is written as <name>.part and renamed when complete, because the window's close ends the process under such a thread and a file cut short there would read as a whole one. A file made in memory first uses plat_file_write_cached or plat_file_write_atomic, which do the same in one call. A change to the helper passes python tests\part_file_check.py, which builds it with the platform layer: nothing stands under the name while a file is written, an older file stays until the new one is complete and after a write that was given up, and a writer killed in the middle leaves the older file whole and the half as .part. No game files.

A change to the log queue (runtime/logq.c) passes python tests\logq_check.py, which builds it with the platform layer and a destination of its own: 160,000 lines from eight threads arrive whole and in each thread's order, a line logged while the queue's lock is taken waits and does not pass the lines queued before it, a destination that takes 30 ms a write does not hold the threads that log, the line about slow writes comes once in ten seconds, a destination that stops while four times the queue's size is logged loses nothing, lines logged together are written in one write a quarter of a second after the first and not before, a queue that is half full is written at once, and logq_sync returns with everything written, the lines the log thread was still gathering included. The program then runs twice more as a process that logs 200 lines to a file and ends at once, by an exit and as a fatal error does: each file holds every line, and the fatal line last. The test passes on a busy machine too: it waits for the queue to empty instead of for a time, counts slow lines instead of timing one, leaves out a check its own thread was too late for, and tries the half-full write three times. No game files.

A change to the button prompts (tools/make_romfs_patches.py --prompts, tools/button_icons.py) passes .venv-py314\Scripts\python tests\romfs_prompts_test.py, which runs the tool on a RomFS it makes itself (no game files); a change to the settings passes nx2navi.exe --probe-cfg.

A change to the action prompt's diamond of face buttons (runtime/action_prompt.c) or to the SARC and zstd dictionary helpers (runtime/sarc.c) passes python tests\action_prompt_check.py. It builds them alone, with the undefined-behaviour sanitizer, on a layout file, archives and dictionaries it makes from the format action_prompt.c's header comment describes, and checks that:

• by label every place, cross, flip and bubble moves and no other byte, in every copy of the layout in the archive;
• a second run changes nothing, and by label then by position gives the game's file back;
• a file that is not the expected one is refused and left as it was: one value off, half laid out, one copy of four, damaged offsets, a pane record laid over the records that lead to another field, more than 16 copies, copies that share some of their bytes;
• the packed file names the dictionary the original named, found by its id in the pack of dictionaries.

No game files. --romfs <folder with romfs.bin and index.json> also runs it on the game's own archive: four copies laid out, 208 fields, the same dictionary and unpacked size, and no byte changed outside the layout's copies.

A change to what the library warm logs when the driver's cache of stage libraries is cold (runtime/vk_warm_hint.h, runtime/vk_pipeline.c lw_main) passes python tests\warm_hint_check.py, which builds the header alone and checks the added text by GPU vendor and by why the cache was cold. No game files.

A change to how a run ends when the GPU device is lost (runtime/vk_device.c vk_device_lost_check, the checks of vk_lost in the replay, upload and present paths, runtime/vk_sync.c completion_main) passes python tests\device_lost_check.py <game exe>, which runs the executable's --probe-devlost: with the device marked lost no completion callback runs and the submit, upload and wait paths return at once, and four threads that report a loss at the same moment end the process with exit code 72, one device report and one FATAL line. It needs a Vulkan device and opens no window; the device is not really lost, so what a driver answers after a loss is not covered. device_lost_at = <n> in nx2navi.ini ends a real run the same way at its n-th hand-over to the GPU queue.

A change to how a fault ends the process (runtime/main.c crash_handler, mode_done) passes python tests\exit_fault_check.py <game exe>, which runs two crash probes: a fault inside a library while a mode runs is a crash (one FATAL line, exit code 71), and the same fault after the mode has returned, while the process is ending, leaves the mode's own exit code and one exit: line. The second is what a library another program put into the process does when it faults in its detach: an injector's Vulkan layer did so at the end of every shader preparation on a player's PC, and the launcher took each finished preparation for a failed one. No game files, no GPU.

A change to the movie timestamp sites of recomp/patches-v111.txt (set omovie) passes python tests\movie_timeline_check.py --cc <clang> (.venv, Unicorn): it lifts the twelve replacement words on their own and compares them with Unicorn over repeated, skipped and rounded timestamps, registers, flags and memory. It does not cover the sites as gen.py emits them inside their two functions, nor the add and store after them: a regenerate of the game code and a compile of the chunk that holds main+0x3b5c7c4 and main+0x3b5c908 does.

A change to the memory gate of the background pipeline builds (runtime/vk_build_gate.h, runtime/vk_pipeline.c gate_enter) passes python tests\build_gate_check.py [<game exe>], which builds the header alone and checks what it admits and refuses and that builds under way count through their reservations. With the executable it also runs --probe-buildgate (no device, no window, no build) with the settings in effect, with build_free_mb = 0 and with a value no machine has free. What the builders do when they are refused (warm_builder, pipe_worker, lb_worker, lw_worker) shows in a run's log: start the game with build_free_mb set above the machine's free commit and read the vk_pipeline: lines that name the commit headroom.

A change to when the pipeline caches are saved in play (runtime/vk_save_retry.h, runtime/vk_pipeline.c autosave_once) passes python tests\save_retry_check.py, which builds the header alone: a save for new content, none without, and after a save that did not happen a bounded row of tries at the save interval.

A change to how FSR 3.1's pipelines reach the pipeline caches (runtime/vk_ffx.cpp vk_ffx_proc_addr, runtime/vk_pipeline.c vk_pipeline_create_foreign) passes python tests\ffx_cache_check.py <game exe>. It runs --probe-ffx-cache (one upscaling context on the device; no window, no game) twice on pipeline cache files of its own and once with ffx_pipe_cache = 0: the library's pipelines must come through the runtime's creates, the second run must compile none of them, and with the setting off none may come through. The executable needs amd_fidelityfx_vk.dll beside it; without it the probe and the test skip. The graphics driver's own cache can serve the first run too, so to see the files alone do it, run the probe from a copy of the executable under a name the driver has not seen: its first run compiles, its second does not.

A change to the start's memory warning (runtime/mem_need.h, runtime/memory.c mem_start_note) passes python tests\mem_need_check.py [<game exe>], which builds the header alone and checks when the game's need counts as short. With the executable it also runs --probe-memneed (it prints the machine's commit and the answer and starts nothing) with mem_need_mb at 0, at 1 and at a value no machine has, and reads the warning line of the last. A change to when a start does the whole warm on the boot screen (runtime/boot_warm.h, runtime/vk_pipeline.c bf_decide) passes python tests\boot_warm_check.py, which builds the header alone: the warm after a driver change, its continuation by a later start, the end of the tries, no second warm once one is done, and what a marker left by a start that ended in the boot's builds means with and without the crash handler's note. The warm itself shows in --probe-prewarm on a copy of an install's caches whose pipeline-cache.bin has another driver's header (bytes 8 to 15 of the file are the vendor and device ids, the 16 after them the driver's cache id): the log names the whole warm, the compute pipelines on every core and the library warm's answer, and boot-warm-owed.txt ends as "done". Run under an exe name the driver has not seen, the probe compiles everything, as after a real driver update. What the boot screen shows, and the builders' step down when the wait is cut short, need a start of the game. A change to how pipeline-cache.bin is read (runtime/vk_cache_file.h, runtime/vk_pipeline.c cache_load) passes python tests\pipeline_cache_file_check.py, which builds the header alone and reads a sparse file just over 2 GB through it: measured and read whole without a size limit, refused by its real size under one. No game files, no GPU; about 2 GB of memory for a few seconds.

A change to how pipeline-binaries.bin is indexed or cut back (runtime/vk_pipeline.c pb_index, pb_keep, pb_init) passes python tests\pb_torn_check.py, which cuts the record layout, the index walk and pb_keep out of vk_pipeline.c and walks files of whole records, with a last record cut short at many lengths and with a malformed record: the whole records before it are indexed and the walk ends where they end, pb_keep cuts the file back to there, a second walk reaches the end of what is left, and a record appended after the cut is read back. No game files, no GPU.

A change to the layout of shader-prepared.bin (runtime/prp_file.h, runtime/gfx_shader.c gfx_shader_prepare_seed, tools/make_game.py prepared_from) passes python tests\prp_file_check.py, which builds the header alone, checks the parse of both versions and has make_game.py read the list the C side wrote. No game files, no GPU.

A change to which translations of a previous translator are served (runtime/gfx_shader.c carry_usable, carry_load, carry_find_iid, carry_last) passes python tests\carry_pool_check.py, which cuts the carry lookups out of gfx_shader.c and runs them against stand-in caches: a translation whose texture pool array has the earlier length (32768) is freed and the lookup goes on, one with the current length or no pool is served, and once the current translator has failed the shader the refused translation serves from the memory cache. No game files, no GPU.

A change to how the translator children are read and restarted (runtime/platform/win32.c plat_child_read, runtime/gfx_shader.c child_exchange_raw, svc_request) passes python tests\child_timeout_check.py, which builds those functions with a 300 ms read timeout and runs cmd.exe children through them: one that never answers costs one timeout and is not asked again, one that exits is restarted once, one that answers gives its line. Windows only; no game files, no GPU.

A change to where the lazy write-back is on by default (runtime/wb_lazy_choice.h, runtime/vk_memory.c vk_mem_lazy_decide) passes python tests\wb_lazy_check.py, which builds the header alone and checks the choice and its reason by platform, by GPU driver and by what the player set. No game files, no GPU.

A change to the lazy write-back's arms, faults, releases or fetches (runtime/memory.c "Lazy write-back" and "Ranges in flight", runtime/vk_memory.c lazy_fetch, mirror_evict, hot_check) passes python tests\lazy_fetch_check.py, which builds memory.c with the Windows fault handler and a fetch that only waits, and runs each scenario as its own process, so an access violation fails it. A thread that reads a range over and over while it is armed and given back again never reaches the crash handler, also when the arm's clean test takes 100 ms, and a read of a range being armed does not either when a range in flight in its region ends during that test. A fetch holds up nothing but the touches of its range: freezes, thaws, arms, releases and copies of other ranges return at once meanwhile, also while a thaw fetches the armed ranges of its own regions, two ranges fetch at once, and more touching threads than the flight table holds all end. The touches of a range in flight wait for it and run again, a write among them without releasing the region's other ranges, also when the flight ended while the write waited for the freeze lock; thaws, mapping changes, releases of its buffer, arms and freezes see it. The same with wb_lazy_chunk = 1, and with wb_lazy_unlocked = 0 the fetch holds the freeze lock again, a thaw's too, and a release fetches one range at a time (the table of ranges in flight stays: a touch of one still waits for it alone). The "mem: lazy write-back" lines give the longest fetch, the longest wait of a fault for the freeze lock and the touches that waited for a range in flight. vk_memory.c's fetch slots, and its evictions (mirror_evict, hot_check: their fetch before pool_lock is taken with wb_lazy_unlocked = 1, under it with 0, and their order against a pool's finalize), have no check without a device. Windows only; no game files, no GPU.

A change to when the freezing of idle guest regions waits (runtime/freeze_hold.h, runtime/vk_memory.c freeze_pass) passes python tests\freeze_hold_check.py, which builds the header alone: the backoff after a slow freeze doubles while slow ones come within the quiet time, fast freezes between them included, stops at its cap and starts over after the quiet time (with a quiet time of 0, at the first fast freeze); and an area load holds the passes while the texture pool loads and for the hold after it or after the area's load. No GPU, no game files.

A change to what writes nx2navi.ini outside the game (launcher/gameini.py, installer/ini.py, tools/make_game.py, launcher/updater.py) passes the settings-file tests of tests\launcher_test.py (PlayerIniTest, and the tests named ..._settings_file of BackgroundUpdateTest and MakeGameTest): a player's file with lines that are no settings of the game comes through an update and a rebuild byte for byte. The game's own writer, the settings menu, is checked by --probe-cfg with the same lines.

A change to the mouse camera's stick deflection (runtime/input_map.c input_mouse_stick) passes python tests\mouse_stick_check.py, which builds that file with the rest of the runtime stubbed and checks the deflection at each camera speed: a slow movement is divided by the factor, a fast flick reaches full tilt. No game files.

A change to how a gamepad's axes are read (runtime/input.c pad_axis: an axis counts once it has been seen at rest) passes python tests\pad_rest_check.py, which builds that function with stand-ins for SDL. No game files.

A change to HD rumble's encoding or report schedule (runtime/rumble_hd.c: a vibration value as the bytes of a Switch controller's rumble report, and which reports are written when) passes python tests\rumble_hd_check.py, which builds that file alone: known values and the neutral one, the frequency and amplitude clamps (no amplitude step above the actuators' safe maximum), a report's data for two actuators and for one, and a batch of values reduced to the reports written (the newest value at once, a held one again every 30 ms, the neutral value three times once the game stops). The script then decodes a sweep of encoded values with formulae of its own. No game files, no SDL, no controller: what a controller does with the reports is not covered.

A change to how a mesh pipeline's fragment module gets the inputs no mesh output feeds (runtime/vk_pipeline.c spirv_mesh_outputs, spirv_fs_fill_inputs) passes python tests\fs_fill_inputs_check.py, which builds both functions and runs them on mesh and fragment shaders it compiles with glslang, then validates the result. No game files.

A change to which render passes count as drawn frame after frame (runtime/vk_target_frames.h: a draw into one is skipped while its pipeline builds, a draw into any other waits) passes python tests\target_frames_check.py, which builds the header alone and replays an area change after a loading screen from a player's log: the scene, probe and half-resolution passes are per-frame again at once, a lookup table, a volume's slices and an icon capture still wait, and an image taken over by another texture starts without the history of the one before. No GPU, no game files.

A change to how the holes in the allocator's blocks are counted or to which blocks a texture compaction empties (runtime/vk_tex_compact.h: tcp_tally, tcp_stats, tcp_plan) passes python tests\tex_compact_check.py, which builds the header alone: a block with one allocation that stays is never chosen, the block that takes the fewest moved bytes goes first, what moves fits the free bytes outside the chosen blocks, a plan under its smallest gain is no plan, and 400 random tables keep those rules. The part of runtime/vk_texture.c that builds the table and moves the images (NX2NAVI_TEX_COMPACT) is not built by it. No GPU, no game files.

A change to which entry of the upscaler stand-in's scratch images serves a new size (runtime/vk_scratch_lru.h, runtime/vk_exec_draw.c fallback_scratch) passes python tests\scratch_lru_check.py, which builds the header alone and checks that a match is a hit, a ninth size takes a free entry or the one used longest ago instead of being refused, and two images of one frame never evict each other. No GPU, no game files.

A change to the ASTC decoder's scratch trim (runtime/vk_astc.c vk_astc_scratch_trim, with the upload lock it only tries, runtime/vk_memory.c vk_defer_buffer_try) passes python tests\astc_trim_check.py, which builds vk_astc.c with the platform layer's recursive lock and the rest of the runtime stubbed: the trim gives way while another thread holds the upload lock, goes through once it is free, and never deadlocks with an upload that asks for the scratch meanwhile. No GPU, no game files.

A change to the copy of each event-ordered queue's first held wait (runtime/vk_evo_peek.h, runtime/vk_exec.c vk_exec_held_ready) passes python tests\evo_peek_check.py, which builds the header alone: one writer republishes while three readers copy, no copy mixes two publishes, and no reader waits for the writer. No GPU, no game files.

A change to how runtime/memory.c mem_copy_readable reads the lazy heap (NX2NAVI_HEAP_LAZY=1) passes python tests\heap_lazy_copy_check.py, which builds memory.c with the Windows platform layer and its fault handler: every copy returns, a heap page nothing touched yet reads zero and stays reserved, and pages past the heap's end are left out. Windows only, no game files.

A change to the page write generations (runtime/vk_memory.c, from its "page write generations" banner to its "dirty census" banner, and the readers of its tables cpu_wrote_since, shadow_pool_clean, lazy_clean, page_dirty) passes python tests\gen_wrap_check.py, which builds those parts of the file alone and runs the generations across 2^32 (where 32-bit generations wrapped), 2^40 and 2^63: texture checks, the snapshot path and the region check, the CPU-side tables, and mirror and shadow cleanliness answer as below the boundary, and one line is logged when the count reaches 2^32. It also takes the start from NX2NAVI_GEN_SEED (gen_seed): read as 64 bits, decimal or 0x, capped at 2^62, a value that is no number ignored, each with its log line. No GPU, no game files.

A change to runtime/vk_memory.c, runtime/vk_texture.c or runtime/tex_probe.c passes python tests\gen_width_check.py, which compiles the three files with the build's flags and -Wshorten-64-to-32, -Wformat and -Wincompatible-pointer-types as errors: the page write generations are 64 bits, and a local, field or format left at 32 bits would bring their wrap back without a word. Any narrowing in these files takes an explicit cast. It needs the shader headers (tools/build_shaders.py); no GPU, no game files.

A change to which frames FSR 3.1 frame generation is told are camera cuts (runtime/vk_fg_reset.h, runtime/vk_fg.cpp generate and vk_fg_frame) passes python tests\fg_reset_check.py, which builds the header alone and checks that each frame id gets its own frame's cut, that an id never noted or no longer held counts as a cut, and that a slot rewritten on another thread never answers an old id with a newer frame's value. No GPU, no game files.

A change to who holds the frame limit with DLSS Frame Generation (runtime/dlssg_pace.h, runtime/vk_dlssg.c vk_dlssg_pace) passes python tests\dlssg_pace_check.py, which builds the header alone and checks that Reflex holds the limit only once Streamline took exactly that limit, that the game's own pacer keeps it during a movie, before the first host present, after 200 ms without one and with the setting off, that frames coming too soon over a window of 60 give it to the pacer for the rest of the run, and that frames the multiplier periods apart switch Reflex to the frames on screen once and to the pacer the second time. No GPU, no game files.

A change to runtime/dlssg/nx2_sl.h or to the export check in tools/build_dlssg.py (declared_exports, pe_exports) passes python tests\dlssg_exports_check.py, which builds a small DLL with MSYS2's clang and checks that the export it lacks is the one named; that build_dlssg.check stops on that DLL, a missing file and a file that is no DLL, and passes a DLL with every export nx2_sl.h declares; that every function nx2_sl.h declares is read; and that tools/make_launcher.py and tools/make_kit.py make that check of their --dlssg DLL before they download anything. The DLL itself is checked when tools/build_dlssg.py builds it, or with --check <dll>. No MSVC, no Streamline SDK, no game files. A change to the list of what the upscalers let go of while the GPU may still use it (runtime/vk_up_defer.h) passes python tests\up_defer_check.py, which builds the header alone, as C and as C++, and checks that an entry goes only once the submission that last named it is done and its present gate is passed, that the ready ones go in the order they were put and the rest keep theirs, that a full list refuses without overwriting, and that an entry a release puts waits for the next take. No GPU, no game files.

A change to where the upscalers free what they let go of (runtime/vk_dlaa.c "what the upscalers let go of while the GPU may still use it", runtime/vk_ffx.cpp and runtime/vk_ffx4.cpp context_for) passes python tests\upscaler_idle_check.py, which reads the sources: vkDeviceWaitIdle only in vk_upscaler_device_idle and the --probe-ffx-cache path, that function only behind the rollback switch, a full list and a refused creation, every place that lets something go calling vk_upscaler_let_go, upscaler_idle_wait's sections[] entry and nx2navi.ini.example line, a name in perf.c for each perf mark kind, and pb_images noting the images' last use after it makes them. Any Python, no game files.

A change to which frames the flight recorder takes for a one-frame flash (runtime/flight_flash.h, runtime/flight.c flight_cells) passes python tests\flight_flash_check.py, which builds the header alone, draws pictures of the thumbnails' size and checks that a patch or a whole frame shown once is a flash, that a camera cut, a fade, a pan and shapes crossing the picture at any speed are none, where each of the test's rules decides, and that a frame beside one without a thumbnail is not judged. With time it prints what the cell means of one thumbnail cost. No GPU, no game files.

A change to the present side's log lines (runtime/vk_backend.c present_main and present_window, the window line of runtime/perf.c perf_present) or to how tools/perf_summary.py reads them passes python tests\perf_summary_check.py. It checks that the format strings it copies are still the runtime's, makes lines with them and checks the present percentiles, the present thread's averages and the hand-off share the tool prints, and that the lines of older logs, without those fields, still parse. Any Python, no game files.

A change to what the frame-time summary charges to an address-space walk of NX2NAVI_MEM_CENSUS (runtime/perf_census.h census_charge, runtime/perf.c ft_frame) passes python tests\census_charge_check.py, which builds the header alone: a walk before, after or around a frame, one still running, a torn read of the last walk's start (taken as no walk), the charge taken from the replay part first, capped by the overlap and the parts, and 100,000 random frames in which the census part never passes the frame and the parts keep their sum. No GPU, no game files.

A change to how the on/off switches read their value (runtime/perf.c rt_knob) passes python tests\rt_knob_check.py, which cuts the function out of the file with its warning table and builds it with stand-ins for the settings and the log: 0, 1 and ab read as before without a line, and any other value reads as 1 and is logged once per switch. No game files.

The lifter (recomp/) and the CPU headers (runtime/cpu.h, runtime/simd.h) are checked against Unicorn. Every lifter change passes these, all run with .venv:

Test	Checks	Game files
tests\diff\lift.py	instructions sampled from the extracted modules; --coverage lists every word the lifter rejects or traps	yes
tests\diff\simd.py	the whole FP/SIMD encoding space	no
tests\diff\atomic.py	exclusive load/store sequences and ARMv8.1 atomics	no
tests\diff\func.py	whole functions as the generator emits them, loops, jump tables and calls included (calls go to a stub that checks the registers at the call)	yes
tests\flags_check.py	the function-local flag helpers of runtime\cpu.h against its packed ones	no
tests\ds3_check.py	the DualShock 3 report decoding and output report of runtime\input_ds3.c	no
tests\gpa_check.py	the device address table of runtime\vk_gpa.c as a shader reads it: mapping, mirrors and twins, overlapping imports, and blocks given back and taken again while pool addresses climb (no GPU; any Python)	no
tests\excl_mt.py	the exclusive monitor helpers under contention, a changed value, and the change-and-restore case the compare-and-swap monitor does not see, on several threads	no
tests\jumptables_check.py	recomp/jumptables.py against a Unicorn oracle; must report 0 disagreements, on 1.4.3 too	yes

A --cpu v2 build passes the same differential tests with --cflags=-march=x86-64-v2; they compile runtime/fma.c too, so they check the software fma the v2 build links rather than the C runtime's.

On NVIDIA Linux, NX2NAVI_DLAA=1 ./ocarina --probe-vkdevice logs NGX initialization and shutdown when available.

Runtime probes, each a mode of nx2navi.exe (the list is at the top of runtime/main.c): --probe-kernel, --probe-vkexec, --probe-nvn-tex and --probe-shader cover most runtime changes. --probe-shader and the draw part of --probe-vkexec translate shaders of the census below: they look for build/<ver>/shaders/jobs.json of the exe's own version first, then of the other one. --probe-vkmem also checks CPU-backed texture uploads and rewrites, GPU-written texture aliases, and memory write watches. --probe-meshfb (no game files) draws mesh programs of the runtime's own, with and without a task stage and with direct and GPU-written workgroup counts, through VK_EXT_mesh_shader and through the mesh fallback, and compares the pictures; on a device without mesh shaders only the fallback draws. A change to runtime/mesh_fb.c, runtime/vk_mesh_fb.c or the fallback's part of runtime/vk_exec_draw.c passes it. With NX2NAVI_PROBE_MESHFB_DIR=<folder> it converts the game's own task and mesh translations instead, for spirv-val (the top of runtime/mesh_fb_probe.c says what the folder holds). A change to the texture detail (runtime/vk_texture.c "texture detail": detail_skip, upload, astc_bl_regions) passes it three times, with NX2NAVI_TEXTURE_DETAIL set to full, reduced and low: each time ASTC textures are uploaded and rewritten, and every level and layer of their images must hold the game's level it stands for. --probe-prewarm runs the boot's pipeline stages without the game, from the caches next to the exe (it skips when there are none): the pipeline cache load, the shader prewarm, the recorded pipelines and the compute pipeline prebuild, with a mem: boot stage log line after each that gives the device memory and the process commit so far. It then asks for compute pipelines the boot did not keep, as their first dispatch would, and prints what one costs. The device memory after the compute stage should be what it was before the stage, apart from the kept pipelines. A change to what the boot builds or keeps (runtime/vk_pipeline.c: prewarm_run, lb_compute, the compute-used.bin record) passes it.

Shaders: .venv-py314\Scripts\python tools\shader_census.py --version <ver> --translate extracts every Maxwell shader to build\<ver>\shaders\ and runs it through the translator and spirv-val; failure groups go to failures.txt. tools\xlate_smoke.py checks the translator alone, without game files.

A change to the SM86 tensor lowering (tools/xlate/AmpereLowering.cs Hmma, Ldsm, Movm, Half) passes python tests\tensor_lowering_check.py: it lowers GPU-captured vectors with nx2navi_xlate --lower and runs them on tests\maxwell_warp_emu.py, a model of what the shader translator makes of Maxwell code (the docstring names the vector file and what is checked). tests\maxwell_warp_emu_selftest.py checks the emulator itself. No game files.

A change to how the packaging scripts check the translator they ship (tools/build_xlate.py source_identity, check_built; make_launcher.py, make_release.py, make_appimage.py, make_kit.py; tools/xlate_smoke.py pool_check) passes python tests\xlate_package_check.py: a folder whose nx2navi_xlate.id names this checkout's sources passes, a missing file, another identity and a folder built before a patch changed are refused, build_xlate.py writes no .id without a build, each script stops before its slow steps, and on Windows make_launcher.py also refuses an exe that does not run beside a matching .id. It needs git on PATH; no game files. tools\xlate_smoke.py --exe <nx2navi_xlate.exe> checks a translator's texture pool length against tools/xlate/Program.cs TexturePoolLength: one older than its sources fails it.

Reverse engineering (optional)

• Ghidra 12.1.2 with the Ghidra-Switch-Loader extension in toolchain\ghidra\ (JDK 21) opens the game modules (NSO).