After the partition is activated, a boot image is located from the boot device, specified

from SMS or the bootlist command, and is loaded into memory. During a normal boot,

the location of the boot image is usually a hard drive. Besides hard drives, the boot

image could be loaded from CD/DVD. This is the case when booting into maintenance

mode for service. If working with the Network Installation Manager (NIM), the boot

image is loaded through the network.

The kernel restores a RAM file system into memory by using information provided in the

boot image. At this stage, the rootvg is not available, so the kernel needs to work with

commands provided in the RAM file system. You can think of the RAM file system as a

small AIX operating system. The kernel starts the init process which was provided in the

RAM file system, not from the root file system. This init process executes a boot script

which is named rc.boot. rc.boot controls the boot process. The base devices are

configured, rootvg is activated or varied on, and the real init process starts from rootvg

which will in turn process the /etc/inittab at run level two.