#!/bin/sh
# Mount the installer image
hdiutil attach /Applications/Install OS X Yosemite.app/Contents/SharedSupport/InstallESD.dmg -noverify -nobrowse -mountpoint /Volumes/install_app

# Convert the boot image to a 8GB sparse bundle
hdiutil convert /Volumes/install_app/BaseSystem.dmg -format UDSP -o /tmp/Yosemite
hdiutil resize -size 8g /tmp/Yosemite.sparseimage

# Mount the sparse bundle for package addition
hdiutil attach /tmp/Yosemite.sparseimage -noverify -nobrowse -mountpoint /Volumes/install_build

# Copy Packages and Base System files to the sparse bundle
rm /Volumes/install_build/System/Installation/Packages
cp -rp /Volumes/install_app/Packages /Volumes/install_build/System/Installation/
cp -p /Volumes/install_app/BaseSystem* /Volumes/install_build/

# Unmount the installer image and sparse bundle
hdiutil detach /Volumes/install_app
hdiutil detach /Volumes/install_build

# Resize the partition in the sparse bundle to remove any free space
hdiutil resize -size `hdiutil resize -limits /tmp/Yosemite.sparseimage | tail -n 1 | awk '{ print $1 }'`b /tmp/Yosemite.sparseimage

# Convert the sparse bundle to ISO/CD master
hdiutil convert /tmp/Yosemite.sparseimage -format UDTO -o /tmp/Yosemite
rm /tmp/Yosemite.sparseimage
mv /tmp/Yosemite.cdr ~/Desktop/Yosemite.iso