I also found this page on the net:

http://www.kernelthread.com/mac/osx/arch_startup.html

you will find it very useful.


GO TO THE WEB PAGE AND LOOK FOR THE PART THAT SAYS:

From here on, the startup becomes user-level:

mach_init starts /sbin/init, the traditional BSD init process. init determines the runlevel, and runs /etc/rc.boot, which sets up the machine enough to run single-user.

During its execution, rc.boot and the other rc scripts source /etc/rc.common, a shell script containing utility functions, such as CheckForNetwork() (checks if the network is up), GetPID(), purgedir() (deletes directory contents only, not the structure), etc.

rc.boot figures out the type of boot (Multi-User, Safe, CD-ROM, Network etc.).

In case of a network boot (the sysctl variable kern.netboot will be set to 1 in which case), it runs /etc/rc.netboot with a start argument.

/etc/rc.netboot handles various aspects of network booting. For example, it performs network and (if any) local mounts.

It also calls /usr/bin/nbst to associate a shadow file with the disk image being used as the root device. The idea is to redirect writes to the shadow file, which hopefully is on local storage.


GOOD LUCK AGIAN