DS game only ov000 minigame
Audition minigame — spell-naming/dictation game where the player selects correct kana sequences for spells NPCs know. Touch-screen candidate grid with scroll, cursor, OK/Cancel. Loads data/2d/audition.lzs. All visible text from RESO type 99 string registry — zero in-overlay translation surface.
Header
Numeric metadata for this overlay as read from the overlay table at ROM
offset 0x8DE00 (per-entry stride 32 bytes). Function
counts, data-item counts, and the call-graph fan-out are from a Ghidra
11.3.1 headless auto-analysis pass.
Reading the binary
The overlay ships on the cart at file ID 0 under the BLZ code-LZ compression wrapper (the same backward-LZ scheme Nintendo uses for executable ARM9 code).
At load time the engine reads the overlay table entry at ROM offset
0x8DE00 + 0 * 0x20, allocates the destination
RAM region at 0x02155a00, decompresses
the body in-place (if compressed), and resolves any external
relocations.
To inspect this overlay outside the running game, decompress
overlay/overlay_000.bin with
ndspy.codeCompression.decompress() (Python ndspy library)
and load the resulting plaintext into Ghidra or
IDA at base address 0x02155a00. The
raw Ghidra auto-analysis dump used to populate this page lives at
notes/overlay_knowledgebase/raw/ov000.json;
the per-overlay descriptive markdown is at
notes/overlay_knowledgebase/ov000.md.
Embedded strings
5 UTF-16 LE strings live inside this overlay's compiled binary. These addresses are absolute (inside the overlay's RAM image after load). The text is stored as little-endian UTF-16 code units, NUL-terminated.
Container references
Distinct container basenames referenced by this overlay. Each is loaded via the content cache by passing the basename string to a lookup that resolves it to a file ID in the ROM's FAT. The path column shows the file's location in the clean extract, where resolved.
-
audition→data/2d/audition.lzs
Unresolved
These container basenames appeared in the overlay's string table but no file of that name was found in the clean extract. Most are false-positive ASCII matches (function names, register maps, fragments of other strings); a few may be containers that the overlay names but never actually opens. Listed for completeness.
-
2d/audition.lzs— no matching container found in clean extract
Function list
Functions Ghidra auto-identified inside this overlay's RAM range.
Names prefixed FUN_ are auto-generated from the function's
entry address; size is in bytes; the "calls" column counts both
intra-overlay branches and external ARM9 call targets. The "strings"
column counts how many UTF-16 LE strings each function references.
Show all 35 functions
| # | Address | Size | Calls | Strings | Role hint |
|---|---|---|---|---|---|
| 1 | 0x02155ce4 | 16 | 0 | 0 | renderer_request_release_5() — sets bit 5 on renderer status byte |
| 2 | 0x02155cf4 | 16 | 0 | 0 | renderer_request_release_1() — sets bit 0 on renderer status byte |
| 3 | 0x02155d04 | 1,242 | 79 | 1 | scene_tick() [vtable 3] — 9-state main game loop. States: load_palettes → wait_assets → wait_render → fade_in → interactive_loop → fade_out → swap_pages → release |
| 4 | 0x02156204 | 16 | 0 | 0 | is_fade_done() — returns 1 when fade animation complete |
| 5 | 0x02156214 | 304 | 23 | 0 | scene_render_vsync() [vtable 4] — per-VBlank sprite push. Iterates 4 top-screen + 8 bottom-screen sprite headers, pushes cursor + alt-card overlay |
| 6 | 0x0215635c | 218 | 10 | 2 | top_screen_bg_init() — allocates 4-sprite top-screen background from audition.lzs |
| 7 | 0x02156454 | 42 | 3 | 0 | top_screen_bg_destroy() — frees top-screen BG draw list |
| 8 | 0x02156484 | 198 | 9 | 2 | bottom_screen_bg_init() — allocates 8-sprite bottom-screen BG with OK/Cancel buttons |
| 9 | 0x0215655c | 48 | 3 | 0 | bottom_screen_bg_destroy() — frees bottom-screen BG draw list |
| 10 | 0x02156590 | 1,352 | 83 | 0 | interactive_frame_handler() — 1352 bytes. Heart of state 5: cursor refresh, idle/swap gate, hotspot polling, DPad dispatch, inactivity timeout, swap animation |
| 11 | 0x02156af8 | 114 | 6 | 0 | cursor_refresh() — detects cursor position change, triggers label relayout |
| 12 | 0x02156b6c | 80 | 3 | 0 | hitbox_test(idx) — tests touch position against 8-entry hitbox table at 0x02157ed4 |
| 13 | 0x02156bd0 | 96 | 1 | 0 | set_cursor_zone(zone, sfx_flag) — maps input zone 0..7 to cursor position, plays SFX 400 |
| 14 | 0x02156c40 | 52 | 3 | 0 | card_select_at_cursor() — plays SFX 0x192, sets selected_card_idx from cursor position |
| 15 | 0x02156c78 | 126 | 10 | 0 | commit_cancel() — cancel commit. Guard: no slot busy. SFX 0x192, page-A swap anim, rewind direction |
| 16 | 0x02156d00 | 100 | 6 | 0 | commit_ok() — OK commit. SFX 0x191, forward swap anim, refresh page-0 glyphs if on page 1 |
| 17 | 0x02156d6c | 98 | 4 | 0 | commit_scroll_up() — SFX 0x2bb, scroll-up animation, timer_swap=6 |
| 18 | 0x02156de0 | 52 | 3 | 0 | commit_scroll_down() — SFX 0x191, scroll-down animation, timer_swap=6 |
| 19 | 0x02156e1c | 956 | 47 | 0 | lay_out_labels(mode) — 956 bytes. Builds per-card text labels. Fetches strings from RESO type 99 (IDs 0x2a1c–0x2a26). Mode 0=relayout, Mode 1=full rebuild |
| 20 | 0x021571f8 | 244 | 9 | 0 | page_meta_sync() — refreshes swap_anim_state from NSC metadata (stage indicator + mode) |
| 21 | 0x021572f8 | 28 | 2 | 0 | disable_scroll_chevrons() — controls scroll-chevron animator direction |
| 22 | 0x02157318 | 96 | 5 | 0 | register_scene_graph_nodes() — attaches 2 scheduler nodes via arm9 0x0200e510 |
| 23 | 0x02157384 | 10 | 0 | 0 | unregister_scene_graph_nodes() — detaches from scene scheduler |
| 24 | 0x02157398 | 284 | 7 | 0 | preload_card_glyphs(page) — 3-pass glyph preloader: base/highlighted/shadow variants per card |
| 25 | 0x021574b8 | 154 | 2 | 0 | request_card_renderers() — requests up to 4+1 card renders from renderer pool |
| 26 | 0x02157554 | 20 | 1 | 0 | request_render() — trampoline to func_0x021599d8 (renderer pool) |
| 27 | 0x02157568 | 52 | 0 | 0 | is_no_slot_busy() — returns 1 if no card in lifecycle state 1 (precondition for OK/Cancel) |
| 28 | 0x0215759c | 1,044 | 7 | 0 | card_animation_step() — 1044 bytes. Per-frame scroll latch, scroll step, state-3 collection, state-1/2 positioning, state-4 retry |
| 29 | 0x021579c4 | 116 | 1 | 0 | release_all_card_slots() — frees all 4 renderer pool slots, resets card lifecycles |
| 30 | 0x02157a38 | 174 | 2 | 0 | is_spell_opcode(npc_iter, opcode) — filters message opcodes 0x14–0x26 for spell content |
| 31 | 0x02157b1c | 82 | 6 | 0 | card_passes_double_filter() — calls is_spell_opcode for both sides, returns 1 only if both pass |
| 32 | 0x02157b70 | 780 | 27 | 0 | seed_cards_from_npc_spells() — 780 bytes. Init-time card seeder: builds 140-entry table, shuffles, sorts by weight, filters by NPC friendship tier |
| 33 | 0x02157e7c | 10 | 0 | 0 | swap_u32(a, b) — swaps a pair of u16s |
| 34 | 0x02157e88 | 18 | 1 | 0 | scene_attach_to_scheduler() [vtable 0] — initializes embedded scheduler list node |
| 35 | 0x02157e9c | 24 | 2 | 0 | scene_detach_from_scheduler() [vtable 1] — re-inits list node, notifies arm9 |
Open questions & conflicts
Open questions / unknowns
- Auto-analysis identified 35 functions covering 8262 of 9728 overlay bytes.
- Function names are auto-generated `FUN_<addr>`. Manual renaming based on call-graph + string-ref analysis is a follow-up.
- BSS size is 0 bytes; Ghidra-imported overlay does not include BSS so any references into the BSS range appear as unresolved.
Conflicts with the prior shallow pass
- Partial overlap: prior-pass had `['audition']`; Ghidra adds `['2d/audition.lzs']`.
Source
- Per-overlay markdown:
notes/overlay_knowledgebase/ov000.md - Raw Ghidra dump:
notes/overlay_knowledgebase/raw/ov000.json - Overlay-system explainer: overlays system
- Plain-English overlay primer: overlay knowledgebase