DS game only 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 82 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 + 82 * 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_082.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/ov082.json;
the per-overlay descriptive markdown is at
notes/overlay_knowledgebase/ov082.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.
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.
-
letterβdata/letter.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/letter.lzsβ 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 34 functions
| # | Address | Size | Calls | Strings | Role hint |
|---|---|---|---|---|---|
| 1 | 0x021597dc | 58 | 7 | 0 | code |
| 2 | 0x021599a8 | 52 | 5 | 0 | code |
| 3 | 0x021599dc | 580 | 23 | 0 | high-fan-out (likely dispatcher / setup) |
| 4 | 0x02159d14 | 124 | 8 | 0 | code |
| 5 | 0x02159d98 | 88 | 4 | 0 | code |
| 6 | 0x02159df0 | 56 | 1 | 0 | code |
| 7 | 0x02159e2c | 26 | 2 | 0 | trampoline / small helper |
| 8 | 0x02159e48 | 8 | 0 | 0 | trampoline / small helper |
| 9 | 0x02159e58 | 110 | 3 | 0 | code |
| 10 | 0x02159ecc | 42 | 1 | 0 | code |
| 11 | 0x02159efc | 84 | 4 | 0 | code |
| 12 | 0x02159f5c | 66 | 3 | 1 | refs: letter |
| 13 | 0x02159fa8 | 10 | 0 | 0 | trampoline / small helper |
| 14 | 0x02159fb8 | 30 | 3 | 0 | trampoline / small helper |
| 15 | 0x02159fd8 | 84 | 3 | 1 | refs: letter |
| 16 | 0x0215a034 | 30 | 1 | 0 | trampoline / small helper |
| 17 | 0x0215a054 | 86 | 5 | 0 | code |
| 18 | 0x0215a0ac | 20 | 0 | 0 | trampoline / small helper |
| 19 | 0x0215a0c4 | 2 | 0 | 0 | trampoline / small helper |
| 20 | 0x0215a0c8 | 80 | 3 | 1 | refs: letter |
| 21 | 0x0215a124 | 28 | 1 | 0 | trampoline / small helper |
| 22 | 0x0215a144 | 94 | 5 | 0 | code |
| 23 | 0x0215a1bc | 12 | 1 | 0 | trampoline / small helper |
| 24 | 0x0215a1c8 | 70 | 3 | 0 | code |
| 25 | 0x0215a21c | 36 | 2 | 0 | trampoline / small helper |
| 26 | 0x0215a244 | 226 | 5 | 0 | code |
| 27 | 0x0215a61c | 30 | 3 | 0 | trampoline / small helper |
| 28 | 0x0215a63c | 36 | 0 | 0 | trampoline / small helper |
| 29 | 0x0215a664 | 52 | 3 | 0 | code |
| 30 | 0x0215a6a0 | 26 | 3 | 0 | trampoline / small helper |
| 31 | 0x0215a6c0 | 10 | 0 | 0 | trampoline / small helper |
| 32 | 0x0215a6d4 | 10 | 0 | 0 | trampoline / small helper |
| 33 | 0x0215a6e8 | 118 | 3 | 0 | code |
| 34 | 0x0215a768 | 12 | 1 | 0 | trampoline / small helper |
Open questions & conflicts
Open questions / unknowns
- Auto-analysis identified 34 functions covering 2396 of 4256 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 32 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/letter.lzs', 'letter']`. Ghidra wins.
Source
- Per-overlay markdown:
notes/overlay_knowledgebase/ov082.md - Raw Ghidra dump:
notes/overlay_knowledgebase/raw/ov082.json - Overlay-system explainer: overlays system
- Plain-English overlay primer: overlay knowledgebase