Wednesday, August 19, 2009

Booting from a dmg

I was pointed by Jean-Francois Roy that it is possible to boot off a dmg.

It's a simple two steps process using bootfolder:

./makebootfolder /Path/to/OperatingSystem.dmg
sudo ./blessbootfolder /Path/to/OperatingSystem.bootfolder

But beware: you better not have a space in the path to the dmg or in the dmg itself. If you happen to try this trick with a space in the path to the boot folder, then your Mac will brick. In verbose startup, you will get

Error loading kernel 'mach_kernel' (0x9)

If you can't boot anymore, download rEFIt and burn it onto a CD. Then boot on the CD by pressing the C key. You should see something looking like this (maybe without the linux and windows partitions):

Just press enter and you should be able to boot your Mac.


Jon Shea said...

I’ve been looking for that for years. The “brick” thing is a little frightening, but I still might be willing to risk it. Thanks a lot.

Anonymous said...

> you better not have a
> space in the path to the
> dmg or in the dmg itself

What if you "escape" the space character with a backslash, or enclose the path in quotes?

Anonymous said...

Anonymous asked about just escaping the space by prefixing it with a back slash. That is all you need to do and it is the correct solution. When I need to plug an address into a command I just drag the file or folder Icon into the terminal window and it adds it escaped spaces and all. Using such a command then works.