Prepare "Install OS X El Capitan.app" for Virtualbox

Question

I'm following these steps to create a DMG file which can be used with VirtualBox. Unfortunately the same steps won't work for Install OS X El Capitan.app. The generated image is not bootable from Virtualbox and drops to an emergency EFI shell. How can I prepare Install OS X El Capitan.app to work with Virtualbox? Installing Yosemite as a VM and then upgrading works but I want to avoid this extra step and do a clean El Capitan install.

Solution

The instructions below, found on [1], worked for me after a download of El Capitan from the App Store.

hdiutil attach "/Applications/Install OS X El Capitan.app/Contents/SharedSupport/InstallESD.dmg" -noverify -nobrowse -mountpoint /Volumes/esd
hdiutil create -o ElCapitan3.cdr -size 7316m -layout SPUD -fs HFS+J
hdiutil attach ElCapitan3.cdr.dmg -noverify -nobrowse -mountpoint /Volumes/iso
asr restore -source /Volumes/esd/BaseSystem.dmg -target /Volumes/iso -noprompt -noverify -erase
rm /Volumes/OS\ X\ Base\ System/System/Installation/Packages 
cp -rp /Volumes/esd/Packages /Volumes/OS\ X\ Base\ System/System/Installation
cp -rp /Volumes/esd/BaseSystem.chunklist /Volumes/OS\ X\ Base\ System/
cp -rp /Volumes/esd/BaseSystem.dmg /Volumes/OS\ X\ Base\ System/
hdiutil detach /Volumes/esd
hdiutil detach /Volumes/OS\ X\ Base\ System
hdiutil convert ElCapitan3.cdr.dmg -format UDTO -o ElCapitan3.iso
mv ElCapitan3.iso.cdr ElCapitan3.iso

[1] http://anadoxin.org/blog/creating-a-bootable-el-capitan-iso-image.html

Comments

[duenni]

Mhh, this drops me to an EFI shell with VirtualBox 5.0.6

[Sean Dawson]

Seems to be working in VirtualBox 5.0.10. Another tutorial for Yosemite which I tried to adapt for El Capitan didn't work but this one did.

[jrock2004]

Did anyone figure this out? I am also dropping to an EFI shell

[user1556435]

Did you change the [System] > [Chipset] setting to PIIX3? Also see apple.stackexchange.com/questions/198737/…