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 12 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 + 12 * 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_012.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/ov012.json;
the per-overlay descriptive markdown is at
notes/overlay_knowledgebase/ov012.md.
Embedded strings
No UTF-16 LE strings are embedded directly in this overlay's binary. Any text it displays at runtime comes from a container file loaded via the content cache.
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.
-
directmailβdata/2d/directmail.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/directmail.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 9 functions
| # | Address | Size | Calls | Strings | Role hint |
|---|---|---|---|---|---|
| 1 | 0x02155ce4 | 16 | 0 | 0 | trampoline / small helper |
| 2 | 0x02155cf4 | 122 | 9 | 0 | code |
| 3 | 0x02155d78 | 246 | 8 | 2 | refs: directmail.lzs \| directmail.lzs |
| 4 | 0x02155e80 | 44 | 3 | 0 | code |
| 5 | 0x02155eac | 110 | 5 | 0 | code |
| 6 | 0x02155f28 | 540 | 37 | 0 | high-fan-out (likely dispatcher / setup) |
| 7 | 0x02156154 | 18 | 0 | 0 | trampoline / small helper |
| 8 | 0x02156168 | 114 | 2 | 1 | refs: %d/%d |
| 9 | 0x021561e4 | 12 | 1 | 0 | trampoline / small helper |
Open questions & conflicts
Open questions / unknowns
- Auto-analysis identified 9 functions covering 1222 of 2336 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 `['directmail']`; Ghidra adds `['2d/directmail.lzs']`.
Source
- Per-overlay markdown:
notes/overlay_knowledgebase/ov012.md - Raw Ghidra dump:
notes/overlay_knowledgebase/raw/ov012.json - Overlay-system explainer: overlays system
- Plain-English overlay primer: overlay knowledgebase