Nerd-World Problems

How To Boot OSX into Darwin Core (Single-User Mode/root#)

Sometimes you need to debug OS X. See exactly what’s going on in the boot process. Or you may just be tired of the GUI (even I, a devout Cocoa addict, can get tired of it) and want to have a good old Command-Line/Shell OS. This is surprisingly easy to do. (This guide only applies to Intel Architecture Systems, which do not have a FileVault Encryption or a Firmware Password enabled.)

At Boot Up (before the chime) Hold:

Shift + CMD + S

(release a few seconds after chime)

The Bootloader will run, and then the system will begin to start in Verbose mode.

at the prompt: check and mount the system and run the launch daemon:

# /sbin/fsck -y

(This checks the system, is not necessary at all, it’s only done for safety reasons. Though it can take a while. Skip it if you’re feeling lucky.)

# /sbin/mount -wu

Now the System is mostly loaded… much of the OS is now available to you. Though you should run the launch daemon for full system capabilities.

# /sbin/SystemStarter

Congratulations… now you have the full Operating System loaded in Single-User Mode, running BASH. This, ladies and gentlemen, is actually Darwin, not OSX (since OSX = Darwin + Cocoa GUI), Apple’s OpenSource BSD Operating System based on the XNU kernel. If the program runs in the Command-Line… it will run here.

remember these important commands:

# shutdown now

shutsdown the computer

# reboot now

reboots the computer

(read the man pages for these for a good chuckle)

Enjoy this Hack!

(Note: The SystemStarter daemon does not seem to work well on some machines, though most programs will run with out this daemon)