Hack64 Wiki yoshis_story
https://www.hack64.net/wiki/
2026-04-04T21:24:30+0000Hack64 Wiki
https://www.hack64.net/wiki/
https://www.hack64.net/wiki/lib/tpl/dokuwiki/images/favicon.icotext/html2019-10-04T17:14:59+0000Anonymous (anonymous@undisclosed.example.com)Level/Object Data Diagram
https://www.hack64.net/wiki/doku.php?id=yoshis_story:data_diagram&rev=1570209299&do=diff
Level/Object Data Diagram
Here is a diagram of this game's pointer spaghetti.text/html2019-10-04T17:11:49+0000Anonymous (anonymous@undisclosed.example.com)File System
https://www.hack64.net/wiki/doku.php?id=yoshis_story:file_system&rev=1570209109&do=diff
File System
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ROM "bank-offset" addressing
Yoshi's Story uses 32-bit “bank-offsets” to point to resources in ROM. The bank table is located at 0x000A79D4 in ROM (0x800A6DD4 in RAM) as an array of bank base addresses. There are 16 available slots for bank addresses, but only bank numbers 0x00, 0x03, and 0x04 seem to be used by the game.text/html2019-10-04T17:10:35+0000Anonymous (anonymous@undisclosed.example.com)Level Data
https://www.hack64.net/wiki/doku.php?id=yoshis_story:level_data&rev=1570209035&do=diff
Level Data
The main level list is at 0x000A84A0 in ROM as an array of 177 “LevelEntry” structs.
LevelEntry struct
This struct simply points to a LevelInfo struct.
struct LevelEntry
{
/*00*/ u32 unk00;
/*04*/ u32 boLevelInfo; // bank-offset of LevelInfo struct
};text/html2019-10-04T17:11:15+0000Anonymous (anonymous@undisclosed.example.com)Object Data
https://www.hack64.net/wiki/doku.php?id=yoshis_story:object_data&rev=1570209075&do=diff
Object Data
The object lookup table is at 0x000A1C90 in ROM as an array of 1582 ObjectEntry structs.
ObjectEntry struct
struct ObjectEntry
{
/*00*/ u16 objectId; // unique identifier
/*02*/ u16 unk02; // probably padding
/*04*/ u32 boObjectDefA; // bank-offset of ObjectDefA struct
/*08*/ u32 boObjectDefB; // bank-offset of ObjectDefB struct
};text/html2019-10-04T17:15:27+0000Anonymous (anonymous@undisclosed.example.com)Object IDs
https://www.hack64.net/wiki/doku.php?id=yoshis_story:object_ids&rev=1570209327&do=diff
Object IDs
Below is an incomplete list of descriptions for each object ID.
IDDescription0x4001Yoshi spawn point0x4002Yoshi egg0x4003? (exporter corrupted texture)0x4004Yoshi egg0x4005Yoshi egg0x4006Happy yoshi0x4010? (exporter corrupted texture)0x4011text/html2019-10-04T17:14:13+0000Anonymous (anonymous@undisclosed.example.com)Overlay Files
https://www.hack64.net/wiki/doku.php?id=yoshis_story:overlay_files&rev=1570209253&do=diff
Overlay Files
Yoshi's Story uses overlays to save memory. The structure of an overlay file is as follows:
u8 text[textSize]
u8 data[dataSize]
u8 rodata[rodataSize]
meta {
u32 textSize
u32 dataSize
u32 rodataSize
u32 bssSize
u32 numRelocations
u32 relocations[numRelocations]
}
u32 metaSizetext/html2019-10-04T17:12:37+0000Anonymous (anonymous@undisclosed.example.com)SMSR00 Compression
https://www.hack64.net/wiki/doku.php?id=yoshis_story:smsr00_compression&rev=1570209157&do=diff
SMSR00 Compression
Yoshi's Story uses an LZ77-type compression format called SMSR00 which is very similar to SM64's MIO0 format. In the Yoshi's Story ROM, each SMSR00 block is preceded by a 16-byte 'CMPR' header which contains the size of the encoded block and its destination size.