BYML: Difference between revisions

=== Header ===

|-

| String “BY” (big endian) or “YB” (little endian) in ASCII (file identifier).

|-

| Version 0x0002 in Breath of the Wild. Values of 1 and 3 are accepted as well.

|-

| Offset to the hash key table, relative to start (usually 0x010). May be 0 if no hash nodes are used. Must be a string value node (0xc2).

|-

| Offset to the string table, relative to start. May be 0 if no strings are used. Must be a string value node (0xc2).

|-

| Offset to the root node, relative to start. May be 0 if the document is totally empty. Must be either an array node (0xc0) or a hash node (0xc1).

|}

Every node format has a unique one byte identifier as follows. Some nodes are considered value nodes as indicated below. The container nodes have a longer encoding in the file, which must be four byte aligned. The order of encoding full nodes within the file does not seem to matter.

|-

| String. Value is an index into the string table.

|-

| Array. Node is an array of nodes, typically, though not necessarily, all of the same format.

|-

| Hash. Node is a mapping from strings in the hash key table to other nodes.

|-

| String table. Special purpose node type only seen in the hash key table and the string table.

|-

| Bool. Node is 1 or 0 representing true or false respectively.

|-

| Int. Node is a signed 32 bit integer value.

|-

| Float. Node is a binary32 floating-point number.

|-

| UInt. Node is an unsigned 32 bit integer value. The game uses this for some CRC32 hashes and for masks.

|-

| Int64. Node is a 64 bit integer value. Not seen in Breath of the Wild.

|-

| UInt64. Node is an unsigned 64 bit integer value. Not seen in Breath of the Wild.

|-

| Double. Node is a binary64 floating-point number. Not seen in Breath of the Wild.

|-

| Null. Value is always 0. Not seen in Breath of the Wild.

|}

==== 0xC0 - Array Node ====

|-

| 0xC0 node type.

|-

| Number of entries in array.

|-

| Array of N node types; the type of each element in the array.

|-

| Array of N node values. For regular value nodes, this is a 4 byte node value. For other nodes, this is a 4 byte offset to the node relative to the start of the file.

|}

Hash / dictionary nodes are used to encode name value collections. The order of entries in the dictionary does not seem to matter.

! Description

|-

| 0xC1 node type.

|-

| Number of entries in dictionary.

|}

What then follows is a variable length array of dictionary entries. Each entry has the following structure.

|-

| Name. Value is an index in the hash key table.

|-

| The node type.

|-

| Value. For regular value nodes, this is the 4 byte node value. For other nodes, this is a 4 byte offset to the node relative to the start of the file.

|}

==== 0xC2 - String Table Node ====

|-

| 0xC2 node type.

|-

| Number of entries in the string table.

|-

| Array of N+1 offsets to each string relative to the start of the node. The last entry is an offset to the end of the last string.

|-

| Array of N null-terminated strings stored in alphabetical order.

|}

''This article was adapted from documentation in the [https://github.com/handsomematt/botw-modding/blob/master/docs/file_formats/byml.md handsomematt/botw-modding repo].''