AppleKeyboardLayouts Binary Template for 010 Editor

AppleKeyboardLayouts.bt

//------------------------------------------------
//--- 010 Editor Binary Template ---
//
//      File: /System/Library/Keyboard Layouts/AppleKeyboardLayouts.bundle/Contents/Resources/AppleKeyboardLayouts-L.dat
//   Authors: vit9696, frkd_dev
//   Version: 2025.07.08
//   Purpose: Apple's proprietary keyboard layout decoding
//  Category: Operating System
// File Mask: *.dat
//  ID Bytes: 02 EF CD AB
//   History:
//            2025.07.08 - rework structs, decipher two previously unknown arrays, struct comments
//            2023.06.27 - parsing of the whole file with data      
//            2018.1 - published at https://github.com/acidanthera/OpenCorePkg/blob/master/Utilities/AppleKeyboardLayouts/AppleKeyboardLayouts.bt
// Copyright (c) 2023,2025 frkd_dev
// Copyright (c) 2018 vit9696
//------------------------------------------------

void SkipPadding(uint64 start)
{
    local uint64 size = FTell() - start;

    /* Four bytes alignment is used across a file */
    local uint64 padding = (4 - (size & 3)) & 3;

    FSkip(padding);
}

typedef struct {
    int32 offset <format=hex>;
    uint32 index <format=decimal>;
} IndexedOffset <read=Str("index=%u name=%s", this.index, ReadString(this.offset))>;

typedef struct {
    int32 layoutID;
    uint32 layoutIndex;
} IndexedLayoutID <read=Str("index=%u id=%i", this.layoutIndex, this.layoutID)>;

typedef struct {
    uint32 magic <format=hex>;
    uint32 layoutCount;
    uint32 layoutInfoTableOffset <format=hex>;
    uint32 unknown1;
    uint32 sortedLayoutTableOffset <format=hex>;
    uint32 unkDataOffset2 <format=hex>;
    uint32 unknown2;
    uint32 unknown3;
} FileHeader;

typedef struct {
    uint32 zero;
    uint32 layoutNameOffset <format=hex>; /* e.g. Czech-QWERTY */
    int32  layoutID <format=decimal>; /* e.g. 30778 */
    uint32 flags; /* ScriptCode? */
    uint32 localeOffset <format=hex>; /* e.g. cs */
    uint32 unknown;
    uint32 layoutDataSize;
    uint32 layoutDataOffset <format=hex>;
    uint32 unicodeRangesSize;
    uint32 unicodeRangesOffset <format=hex>;
    uint32 iconSize;
    uint32 iconOffset <format=hex>;
    uint32 modPlistSize;
    uint32 modPlistOffset <format=hex>;
    uint32 plistSize;
    uint32 plistOffset <format=hex>;
} LayoutInfo <read=Str("id=%i name=%s", this.layoutID, ReadString(this.layoutNameOffset))>;

typedef struct (LayoutInfo& info) {
    string layoutName;
    SkipPadding(startof(layoutName));
    
    /* In rare cases locale offset could be empty */
    if (info.localeOffset) {
        string locale;
        SkipPadding(startof(locale));
    }

    wchar_t layout[info.layoutDataSize / 2];
    SkipPadding(startof(layout));

    wchar_t unicodeRange[info.unicodeRangesSize];
    SkipPadding(startof(unicodeRange));

    if (info.iconOffset != 0 && info.iconSize != 0) {
        byte icon[info.iconSize];
        SkipPadding(startof(icon));
    }

    if (info.modPlistOffset != 0 && info.modPlistSize != 0) {
        byte modPlist[info.modPlistSize];
        SkipPadding(startof(modPlist));
    }

    if (info.plistOffset != 0 && info.plistSize != 0) {
        /* #include "BPlist.bt" */
        byte plist[info.plistSize];
        SkipPadding(startof(plist));
    }
} LayoutData <read=this.layoutName>;

typedef struct {
    local int i;
    FileHeader fileHeader;

    Assert(fileHeader.magic == 0xABCDEF02, "Invalid magic!");

    struct {
        for(i = 0; i < fileHeader.layoutCount; i++)
            LayoutInfo info;
    } layoutInfo <comment="An information array about each layout in a file (size, offset to data, id, icon, etc.)">;
    
    struct {
        for(i = 0; i < fileHeader.layoutCount; i++)        
            IndexedOffset item;
    } sortedLayoutNameIndexes <comment="Array of layout indexes and offsets sorted by a layout name">;
    
    struct {
        for(i = 0; i < fileHeader.layoutCount; i++)
            IndexedLayoutID item;
    } sortedLayoutIDIndexes <comment="Array of layout IDs and indexes sorted by a layout ID">;
    
    struct {
        for(i = 0;i < fileHeader.layoutCount; i++)
            LayoutData data(layoutInfo.info[i]);
    } layoutData <comment="Array of layout data referenced in info">;
} KeyboardLayout;

KeyboardLayout keyboardLayoutFile;

This file is no longer updated/maintained.
Please check for updates in my "binary-templates" repository.