To include additional application or file packages in an operating system installer disk image, copy the packages into the image, and then use a text editor such as TextEdit to update the property list (.plist) file that describes the packages in the image.
Follow these steps to add packages to an OS installer disk image:
1. Make sure the disk image file (.dmg) is unlocked. If necessary, select the image file in the Finder and choose Show Info from the File menu. Be sure the Locked checkbox is not selected. You may need to log in as the root user to unlock the file.
2. Double-click the image file to mount it.
3. Copy your packages or metapackages into the following folder in the mounted image: /System/Installation/Packages
4. In the same folder, Control-click the OSInstall.mpkg file and choose Show Package Contents from the shortcut menu.
5. Open the Contents folder (inside OSInstall.mpkg).
6. Use a text editor to open the file Info.plist. To open the file in TextEdit, for example, drag the file's icon onto the icon for the TextEdit application.
7. Add a new <dict>...</dict> entry for your package within the array of entries under the key IFPkgFlagPackageList. You can copy one of the existing entries, then just change the value of the IFPkgFlagPackageLocation key to the name of the package you put in the Packages folder.
8. Repeat step 6 for each package you want to install.
9. Save the updated property list.
10. Eject the image.
Important software license information
In accordance with the Network Install and Mac OS X Server software license agreements, you may use the software in this manner as long as you ensure that each end user of the image files is aware of and complies with the terms of the software license(s) that governs the use of the software contained within the image files. The Network Install and Mac OS X Server software may be used to install and reproduce materials so long as your use is limited to reproduction of non-copyrighted materials, materials in which you own the copyright, or materials you are authorized or legally permitted to reproduce.