Datasheet
GSHT (G?sheet) is a custom Grezzo binary serialization file format that is used to store structured, strongly typed data. GSHT documents are called datasheets.
| File format | |
|---|---|
| Magic | gsht |
| Endianness | little |
| Version | 1 |
| This article is about the file format in general. For actual values, check the game RomFS. | |
A datasheet contains structure type information followed by arrays of structures. Optionally, one of the structure fields may be declared as a key field, in which case the contents are a dictionary rather than a array.
Format
Documents are little endian and their sizes are always 0x10-byte aligned.
Header
| Offset | Type | Description |
|---|---|---|
| 0x0 | char[4] | Magic (GSHT or gsht)
|
| 0x4 | int | Version (must be 1) |
| 0xC | u8 | Bool type size (must be 1) |
| 0xD | u8 | Pointer size (must be 8) |
| 0xE | u8 | ?[check] |
| 0x10 | const char* | Name |
| 0x18 | u32 | Number of main fields |
| 0x1C | u32 | Number of fields in total |
| 0x20 | Value* | Values |
| 0x28 | u32 | Number of values |
| 0x2C | u32 | Value size |
Field
enum class Type : u16 {
Struct = 0,
Bool = 1,
Int = 2,
Float = 3,
String = 4,
};
enum class Flag : u16 {
IsNullable = 1 << 0,
IsArray = 1 << 1,
IsKey = 1 << 2,
b3 = 1 << 3,
IsEnum = 1 << 4,
b5 = 1 << 5,
};
| Offset | Type | Description |
|---|---|---|
| 0x0 | const char* | Name (must be non-null) |
| 0x8 | const char* | Type name |
| 0x10 | Field::Type | Type |
| 0x11 | u8 | ?[check] |
| 0x12 | Field::Flag | Flags |
| 0x14 | u16 | Value offset |
| 0x16 | u16 | Value blob size |
| 0x18 | u16 | Value size |
| 0x1A | u16 | Structure field count |
| 0x20 | Field* | Structure fields |
| 0x28 | Field* | Parent (filled in during parsing; always 0xdeadbeefdeadbeef when serialized) |
Fields must be properly aligned to 0x30 byte boundaries.
Key fields cannot be arrays or Nullable types.
Key fields must be of type String or Int.
Value
| Type | Serialized data format |
|---|---|
| Nullable<T> (non-strings) | struct { T* data; } (nullptr if no value)
|
| Array<T> | struct { T* data; u32 size; } (aligned to 0x10 bytes[check])
|
| Struct | struct { Fields...; }
|
| Bool | bool (1-byte) |
| Int | s32 |
| Float | f32 |
| String | struct { const char* data; u32 length; } (aligned to 0x10 bytes)
|
A value is simply serialized data for the structure formed of main fields.
Usage in Link's Awakening
Datasheets are extensively used to configure game logic and to store miscellaneous data. They are located in rom:/region_common/datasheets and their file extension is .gsheet.
Text versions of datasheets are available in the leoetlino/la-re-notes repository on GitHub.