Dreamcast Image Builder/Adding Games

Adding Games in the UI

In addition to built-in games, but you can add support for more games by clicking the + icon to the right of the Games list and selecting a GDI file.

When you pick a GDI file, you will see the following dialog:

Brief Title is the internal name used by this program. It will be used as a filename base for files containing game settings. It's recommended to use short but descriptive names for game data files, such as SA1_INT1003 (Sonic Adventure International v.1.003).

Display Title is the game's name that will appear on the Games list. Note that each game configuration must have a unique title.

The settings below are optional.

Icon is an icon associated with the game. It is only used for cosmetic purposes. Click the box to locate a bitmap or icon file. If you click Cancel in the open file dialog, the current icon will be cleared.

Cheats locates a RetroArch .cht file associated with this version of the game. If you specify a valid cheat sheet, the Codes tab will appear when this game is selected. If you click Cancel in the open file dialog, the current cheat table will be cleared.

Sort List locates a file list used for arranging files in a specific order (such as the sort files exported by GD-ROM Explorer). It's only used for building CDI files. If you click Cancel in the open file dialog, the current sort list will be cleared.

Boot LBA is the value used for selfbooting CDI. It depends on the game and the selfboot method used.

CDI Patches is a list of hacks for 1ST_READ and other binaries required to boot the CDI. CDI patches are in the following format:

Comment,Filename,Offset,Type,Count,Value

For more information on patches, see the section below.

Adding Games Manually

To add games manually, create a games folder in the same location as DreamcastImageBuilder.exe and add game-specific data to it.

Game Data

Game data includes the following files:

INI file with game metadata
(Optional) Game icon (.ico file)
(Optional) Cheat table in RetroArch .cht format (for flycast)
(Optional) Sort file (such as those created by GD-ROM Explorer) with the .str extension

Game data must be placed in the games folder. It's recommended but not required to create a subfolder for each game.

All files for the same game must have the same name, for example if you name the INI file MYGAME.INI, then the icon should be MYGAME.ICO, the sort file should be MYGAME.STR and the cheat table should be MYGAME.CHT.

It's recommended to use short but descriptive names for game data files, such as SA1_INT1003 (Sonic Adventure International v.1.003).

INI file

The INI file is the minimum requirement for Dreamcast Image Builder to be able to build modified GDIs for the game. It's a text file that consists of the following lines:

Line 1: Game title (to be displayed in the UI) 
Line 2: Game identifier (used to check GDI versions and mod compatibility) 
Line 3: Number of tracks (unused) 
Line 4: Boot LBA for CDI (0, 11700, 11702 or 45000) 
Line 5 and below: Patches required to boot in CDI mode

Important: Do not add comments or extra line breaks between the lines.

Game title only affects the interface of the program. It's recommended to include the full game title and version, such as "Sonic Adventure International 1.003".

Game identifier is a string used to recognize the specific version of the game. You can retrieve it from the following locations in a GDI dump:

track03.bin: from 0x50 to 0x70
IP.BIN: from 0x40 to 0x60

Example: 610-7029 V1.00019981016 for Sonic Adventure Autodemo.

The text in that area usually takes less than 32 bytes, and the remainder of the string is filled with spaces (0x20). You can remove the trailing spaces, but do not remove the spaces in the middle of the string (between 7029 and V1.0001 in the example above).

Number of tracks is for compatibility with the old format of game INI files. You can leave the value at 3.

Boot LBA is the sector ID used to boot the CDI file. It can be different depending on the game and the selfboot method used to make the game boot from a CD.

Patches for CDI are hacks that need to be applied to 1ST_READ.BIN and other binaries to make the game boot from a CD. Each line is a separate patch (see below).

Lines 4 (Boot LBA) and 5+ (Patches for CDI) are not required if you only want to build GDIs.

Here's an example INI file for Sonic Adventure International:

Sonic Adventure International 1.003
HDR-0043 V1.00319990920
3
11702
LBA Patch,1ST_READ.BIN,65DD50,Uint16,1,11868

CDI patches are in the following format:

Comment,Filename,Offset,Type,Count,Value

In the SA International example above, the patch called "LBA Patch" writes the unsigned 16-bit integer value of 11868 (2E 5C) once at offset 0x65DD50 in 1ST_READ.BIN. For other value types that can be used in patches, see Creating Mods.

You can find more examples of game data in the built-in games folder.

Overriding Built-in Games

If you need to modify settings for a game that Dreamcast Image Builder has built-in support for, you can do so by matching your game data filenames with the built-in names:

Sonic Adventure (US v.1005): SA1_US1005
Sonic Adventure 2 (US v.1008): SA2_US1008
Sonic Adventure Autodemo prototype: SA1_Autodemo
Rez (Japan): Rez_JP1003
Rez (Europe/PAL): Rez_EU1003
Rez (Build 836 prototype): Rez_b836

Adding CDI support

To add support for building CDIs for a game, the following data is required:

The INI file must specify the required Boot LBA (msinfo value). At the moment only the value of 11702 has been confirmed to work.
The INI file must contain patches for 1ST_READ.BIN (and possibly other binaries) to remove the game's GD-ROM protections, if any. There is an experimental setting in the Options tab to bypass common GDROM protections, which may be enough for some games.
For games that don't use Windows CE, the INI file must contain patches for 1ST_READ.BIN to replace the Boot LBA value in cases when it isn't 45000. There is an experimental setting in the Options tab to auto patch Boot LBA, which may be enough for some games.