ov080 β€” overlay detail

DS game only γ¨γ‚“γŒγ‚Šγƒœγ‚¦γ‚·γ¨γŠγ—γ‚ƒγ‚Œγͺまほう぀かい The field guide documents the DS game's internals.

containers: map/fish/fish.ofs, map/insect/insect.ofs

ov080 other

containers: map/fish/fish.ofs, map/insect/insect.ofs

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.

Overlay ID 80
File ID 80
RAM load address 0x021597a0
RAM size 5,088 bytes (0x13e0)
BSS size 0 bytes
On-disk compressed size 4,060 bytes
Compression flag 0x1 (BLZ-compressed)
Functions 19
External calls 37
Jump tables 2
Data items 49
Code coverage 33% (1,690 of 5,088 bytes)

Reading the binary

The overlay ships on the cart at file ID 80 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 + 80 * 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_080.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/ov080.json; the per-overlay descriptive markdown is at notes/overlay_knowledgebase/ov080.md.

Embedded strings

1 UTF-16 LE string 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.

0x0215a3ac `榑槒樣ぜ`

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.

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.

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 19 functions
# Address Size Calls Strings Role hint
1 0x02159964 92 6 0 code
2 0x021599d8 50 2 0 code
3 0x02159a0c 24 1 0 trampoline / small helper
4 0x02159a24 32 1 0 trampoline / small helper
5 0x02159af0 42 0 0 code
6 0x02159e58 22 1 0 trampoline / small helper
7 0x02159e74 22 1 0 trampoline / small helper
8 0x02159e90 172 8 1 refs: map/insect/insect.ofs
9 0x02159f44 6 0 0 trampoline / small helper
10 0x02159f50 172 8 1 refs: map/fish/fish.ofs
11 0x0215a00c 592 29 0 high-fan-out (likely dispatcher / setup)
12 0x0215a290 42 0 0 code
13 0x0215a3c4 48 0 0 code
14 0x0215a8a0 64 0 0 code
15 0x0215a8e8 152 7 0 code
16 0x0215a98c 92 4 0 code
17 0x0215a9e8 30 1 0 trampoline / small helper
18 0x0215aa0c 24 1 0 trampoline / small helper
19 0x0215aa28 12 1 0 trampoline / small helper

Open questions & conflicts

Open questions / unknowns

Conflicts with the prior shallow pass

Source