Make a Snow Leopard 10.6.7 Installer Disc from a Mac Restore Disc

So there was this hint the other day at MacWorld's OS X Hints site:
10.6: Make a universal 10.6.7 Snow Leopard installer – Mac OS X Hints

It was a very useful hint for hacking together a retail Snow Leopard disc (10.6.0/10.6.3 ) and the newest system specific restore disc (10.6.7 for iMacs and MacBook Pros) to make a "universal" 10.6.7 disc that would work on new and old machines alike, that are qualified to run Snow Leopard. Useful not only for techs who need a one disc does it allbut others who might lack bandwidth for updates since this cuts down on some Software Update downloads (10.6.8 is only a smaller "delta" update this way.)

So, it was a good hint because it got to the heart of the matter, that OSInstall.mpkg was where the script logic determines if your machine is qualified for the restore. However using the original 10.6 disc and copying over all the old printer drivers is a little too kludgy for me, the less donethe better. I knew there had to be a more elegant way…

Voila – this bash script strives for automagic: it reads in your restore disc, prompts you to grab your disc and pop in a blank DVD, then modifies the install logic, and burns the disc you can use on all your Snow Leopard elligible Macs (P.S. Don't steal OS X). It hasn't been QC'd or QA'd beyond a few runs using one set of 10.6.7 restore disc, but I hope it comes in handy for some Mac tech out there somewhere who is in a pinch and needs to restore Snow Leopard – if only to get App Store on a machine and then up to 10.7 or 10.8!

makeUniversalSnowLeoDisc.command

#!/bin/bash
clear

destination=~/Desktop/Mac\ OS\ X\ Install\ DVD

#make destination folder
[ ! -d "$destination" ] && mkdir "$destination"

#make sure disc is in drive
while [ ! -d /Volumes/Mac\ OS\ X\ Install\ DVD ] ; do
echo Please insert Mac OS X Install DVD and press Enter
read
done

#get device node for block copy
device=$(diskutil info /Volumes/Mac\ OS\ X\ Install\ DVD/ | grep Node | cut -f2 -d:)

#create disk image from device (retains Finder window custom background)
echo "Creating Disc image at $destination, please wait..."
/usr/bin/hdiutil create -srcdevice $device -format UDRW "$destination"/Mac\ OS\ X\ Install\ DVD.dmg
#disk image using source folder (loses custom Finder background)
#/usr/bin/hdiutil create -srcfolder /Volumes/Mac\ OS\ X\ Install\ DVD/ -format UDRW "$destination"/Mac\ OS\ X\ Install\ DVD.dmg

#eject media
/usr/bin/drutil eject

#tell user to take out disc
echo -e $'\a'$'\a'$'\a'$'\n'"Please Remove the disc and press Enter"$'\n'
read

echo "Modifying Image"
#mount r/w image
hdiutil attach "$destination"/Mac\ OS\ X\ Install\ DVD.dmg
#expand OSINstall.mpkg
/usr/sbin/pkgutil --expand /Volumes/Mac\ OS\ X\ Install\ DVD/System/Installation/Packages/OSInstall.mpkg /Volumes/Mac\ OS\ X\ Install\ DVD/System/Installation/Packages/OSInstall.expanded
#modify Distribution script in place with no backup
/usr/bin/sed -i '' "s/modelProp\ \=\=\ hwbeSupportedMachines\[i\]/1/g" /Volumes/Mac\ OS\ X\ Install\ DVD/System/Installation/Packages/OSInstall.expanded/Distribution

#modify Distribution script in place with backup (for sissies)
#/usr/bin/sed -i '.original' "s/modelProp\ \=\=\ hwbeSupportedMachines\[i\]/1/g" /Volumes/Mac\ OS\ X\ Install\ DVD/System/Installation/Packages/OSInstall.expanded/Distribution

#remove original OSInstall.mpkg package
/bin/rm -rf /Volumes/Mac\ OS\ X\ Install\ DVD/System/Installation/Packages/OSInstall.mpkg

#flatten new package
/usr/sbin/pkgutil --flatten /Volumes/Mac\ OS\ X\ Install\ DVD/System/Installation/Packages/OSInstall.expanded /Volumes/Mac\ OS\ X\ Install\ DVD/System/Installation/Packages/OSInstall.mpkg

#remove expanded folder
/bin/rm -rf /Volumes/Mac\ OS\ X\ Install\ DVD/System/Installation/Packages/OSInstall.expanded

### image is now ready to be burned ###

#eject disk image
hdiutil eject /Volumes/Mac\ OS\ X\ Install\ DVD/

#burn disc image
/usr/bin/drutil burn "$destination"/Mac\ OS\ X\ Install\ DVD.dmg

echo -e $'\a'$'\a'$'\a'$'\n'"Disc Complete, Please Remove the disc"$'\n'