Mac OS X Booting

Here , I am just pointing about how to boot MAC OS .

Little Talk about FIRMWARE , The firmware is not pare of MAC OS X, but it plays an important role in the operation of the machine.


Open Firmware :

Open firmware is a non proprietary, Platform (CPU and System) independent boot firmware, similar to a PC’s BIOS, Open Firmware is stored in ROM and is the first stored program to be executed upon power UP. Apple and SUN are two prominent computer system makers that use implementations of open firmware in their systems.

The Firmware is implemented in forth programming language, and stored in the ROM as Code byte code,Device drivers that are required during system Startup are also implemented similarly, such drivers usually exist in the expansion ROM of expansion cards that are needed before the operating system has loaded.


() Open firmware by pressing the key combination (cmd-opt-0-F)  just as you on a Macintosh.

  The cmd keys is the one with the apple logo .

   The opd key is the same as the alt key.

     You can see a welcome message and other messages and dropped into a prompt message like



0 >


you can continue booting the machine by typing (mac-boot) or shut it down by typing (shut-down).



If you want to access a MAC’s open firmware from another arbitrary computer,over the network, here is the command.


0 >  dev/packages/telnet


More details


Boot Loader


BootX(/system/library/coreservices/Bootx) is the default bootloader on MAC OS X.


BootX can load kernels from various filesystem : HFS+,HFS,UFS,ext2, and TFTP



More Boot loader Information you Can see the Source  page


Wolf - 150 x 150