ov081 — 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 81 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 + 81 * 0x20, allocates the destination RAM region at 0x021597a0, decompresses the body in-place (if compressed), and resolves any external relocations.

To inspect this overlay outside the running game, decompress overlay/overlay_081.bin with ndspy.codeCompression.decompress() (Python ndspy library) and load the resulting plaintext into Ghidra or IDA at base address 0x021597a0. The raw Ghidra auto-analysis dump used to populate this page lives at notes/overlay_knowledgebase/raw/ov081.json; the per-overlay descriptive markdown is at notes/overlay_knowledgebase/ov081.md.

Embedded strings

4 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.

• friend → data/2d/status/friend.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/status/friend.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.

Open questions & conflicts

Open questions / unknowns

• Auto-analysis identified 87 functions covering 6852 of 11360 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

• **Mismatch:** prior-pass `controls_containers` = `['status']`; Ghidra-extracted containers = `['2d/status/friend.lzs', 'friend']`. Ghidra wins.

Source

• Per-overlay markdown: notes/overlay_knowledgebase/ov081.md
• Raw Ghidra dump: notes/overlay_knowledgebase/raw/ov081.json
• Overlay-system explainer: overlays system
• Plain-English overlay primer: overlay knowledgebase