ov159 — overlay detail

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 159 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 + 159 * 0x20, allocates the destination RAM region at 0x021c3420, decompresses the body in-place (if compressed), and resolves any external relocations.

To inspect this overlay outside the running game, decompress overlay/overlay_159.bin with ndspy.codeCompression.decompress() (Python ndspy library) and load the resulting plaintext into Ghidra or IDA at base address 0x021c3420. The raw Ghidra auto-analysis dump used to populate this page lives at notes/overlay_knowledgebase/raw/ov159.json; the per-overlay descriptive markdown is at notes/overlay_knowledgebase/ov159.md.

Embedded strings

43 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.

• NpcCstm → data/npc/NpcCstm.ofs
• pack1gcmn → data/pc_shop/redecoration/inner/pack1gcmn.lzs
• pack1gseled → data/pc_shop/redecoration/inner/pack1gseled.lzs
• pack1gseling → data/pc_shop/redecoration/inner/pack1gseling.lzs
• pack2 → data/pc_shop/redecoration/inner/pack2.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.

• (npc/NpcShopEst.lzs — no matching container found in clean extract
• /2d/touchicon.lzs — no matching container found in clean extract
• /map/shop/back_sell.ofs — no matching container found in clean extract
• /npc/NpcMeddleCmd.lzs — no matching container found in clean extract
• /npc/consider.lzs — no matching container found in clean extract
• /npc/relation.lzs — no matching container found in clean extract
• NpcDataOfs
• billboard1 — no matching container found in clean extract
• billboard2 — no matching container found in clean extract
• billboard3 — no matching container found in clean extract
• billboard4 — no matching container found in clean extract
• data_Sheet1 — no matching container found in clean extract
• data_SheetH — no matching container found in clean extract
• map/route/plane%s.lzs — no matching container found in clean extract
• map/route/route%s.lzs — no matching container found in clean extract
• npc/NpcBuyChk.lzs — no matching container found in clean extract
• npc/NpcParam.lzs — no matching container found in clean extract
• npc/NpcPlan.lzs — no matching container found in clean extract
• npc/NpcPlanEX.lzs — no matching container found in clean extract
• npc/NpcPlanSH.lzs — no matching container found in clean extract
• npc/visit.lzs — no matching container found in clean extract
• topic/tpc_cng.ofs — 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.

Open questions & conflicts

Open questions / unknowns

• Auto-analysis identified 1065 functions covering 116108 of 222848 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 6048 bytes; Ghidra-imported overlay does not include BSS so any references into the BSS range appear as unresolved.

Conflicts with the prior shallow pass

• No major conflicts detected with prior-pass `overlay_role_final.json` record.

Source

• Per-overlay markdown: notes/overlay_knowledgebase/ov159.md
• Raw Ghidra dump: notes/overlay_knowledgebase/raw/ov159.json
• Overlay-system explainer: overlays system
• Plain-English overlay primer: overlay knowledgebase