Cuphead

Update 1.3.7 (v655360) over the base game; its DLC (The Delicious Last Course) is mounted as add-on content 1. SDK 5.5.0, NVN API 53.313. Unity 2017.4.9f1 IL2CPP on NVN. Modules main, subsdk0 (the movie module, NintendoSDK_movie) and sdk. Plays on the iPhone. On the Mac it was brought up with no host change: the title, the save slots, the opening storybook, Elder Kettle's house, Inkwell Isle One and Forest Follies at 60 fps with no red line. Unity 2017.4's serialized and Shader formats (unityfs.py, shader_split.py) and the rewriter's jump-table form (patch_nso.py) were found by armyja on this game (GitHub pull requests #1, #2).

What it needs

Memory

• No system resource, so no virtual address memory: Unity sets a heap of the application pool − used memory (3.12 GB) in the 4 GB block and allocates from it.
• On the Mac about 3.2 GB resident and 2.7 GB of Metal allocations, flat over the house and the map.

Rendering

• Resolved: sprites broke into dark slivers or went missing in about half the runs (a log in Forest Follies splintered for a whole attempt), and on the iPhone the picture flickered every fourth frame. The host reported a ZCull storage size of 0. Unity's NVN pool allocator allocates each depth target's ZCull save area from its pool; asked for a zero-size block, it gave out the offset of a live block, lost that block from its map of allocations, and later freed it with a garbage size. Buffers allocated afterwards overlapped live ones, so copies read staging bytes another copy had overwritten (every fourth frame is the upload ring's period); whether a run broke depended on the allocation order. The size is now never 0 (zcull_size).
• How it was traced: the pass dump (DM_NVN_PASSDUMP_ALL=1, the Y copy_b2b / Y update_ub lines) listed in command order every copy and inline update of the frame. A copy whose source an earlier GPU write of the same frame covers reads that write, not the bytes the CPU staged: the broken runs had dozens of those a frame, the clean runs none. The game's allocations overlapped, so the allocator was tracked from observation gates (OBS in its patches.py) on its free-list push and after its map insert, checking at every event that each block allocated so far was still in the game's map.

Files and shaders

• 3,118 shaders (1,558 pixel, 1,560 vertex) from the player's serialized files and the AssetBundles of StreamingAssets, plus 4 GLSLC outputs in main. Every binding decodes.
• Its Unity 2017.4 layout is the one AI: THE SOMNIUM FILES (010089B00D09C000) reads with. Before Unity 2019.3 a Shader keeps one segment per platform, the form Cuphead's trees gave shader_programs.
• Its 2 ComputeShader objects are only in files without type trees, of hashes no layout covers; the split prints a [RED] line and leaves their kernels out.

Saves

• The game writes a slot when it reaches the map, not when the slot is picked.

Mac routes

• A fresh save through the title (L+R), a new slot, the storybook and the house to the map (at about 160 s): DM_KEYS="20:L+R,26:A,32:A,38:A,44:A,50:A,56:A*20/3,120:LRight~4,125:A,127:LRight~3,131:A*10/2,152:LLeft~3,155.5:A".
• From that save, across the bridge (its entry is narrow between the posts) into Forest Follies (play from about 68 s; Y shoots): DM_KEYS="20:L+R,26:A,32:A,35:A,40:LRight~1.5,42:LDown~1.5,45:LRight~3,49:LUp~1,51:LRight~3,54.5:LLeft~0.5,55.2:LUp~0.25,55.6:LRight~2,58:LUp~0.2,58.4:LRight~0.25,58.8:LUp~0.2,59.2:LRight~0.25,59.6:LUp~0.2,60:LRight~0.25,60.4:LUp~0.2,61:A,63:A".

Found on this game

General host changes first needed here; each applies to every game:

• A size the hardware never reports as 0 is never 0 on the host (zcull_size): Sizes the hardware never reports as 0 (ZCull save area).
• Overlapping copies in the pass dump as the sign of a broken game allocator: 05, Intermittent rendering glitches.
• mem_used for rewritten modules over 64 MB, which the NSP script now sets after the rewrite: dm/games/README.md, Keys and Adding a game.
• Unity 2017.4 serialized and Shader formats (unityfs.py, shader_split.py) and the rewriter's jump-table form (patch_nso.py), by armyja: shaders.md, Containers by engine, Offset jump tables with the bounds check on another register.

Open

• "SDK 5.5.0 (the oldest so far)" in game.tsv and docs/development.md is stale: DARK SOULS: REMASTERED (4.5.0) and Mario Kart 8 Deluxe (4.4.0) are older.
• The tracing text in nvn-objects.md names observation gates "in its patches.py"; the profile has no patches.py now.
• game.tsv has no sys_resource row, so the host reports its default, 32 MB (game.py, hle_svc.c), although the NPDM declares none and the notes describe the game as having no virtual address memory. Not checked against the game's behaviour.