The Boot Process Of A Cash Register System - Novell SLRS 8 Admin Manual

9 The Boot Process of a Cash
Register System
To understand how to use the operating system images, a short description of
the cash register system is useful. The following diagram shows the simplified
boot process of a cash register system.
No
Have Disk System ?
Figure 9.1: Simplified Flow Chart of the Boot System
The most important point is to understand the cooperation between the initial
boot image initrd.gz and the intrinsic cash register image. If the system is able
to boot via a network, it will load the kernel and the compressed boot image
from the network. The brain of the boot image is the linuxrc script, which
does all the stuff controlled by an image configuration file also obtained from
the network. The major task is to download and activate the cash register im-
age. The boot image is exchanged for the cash register image to be activated.
Normally, only work with the cash register images and leave the boot image
as it is delivered from SUSE.
The following short overview describes the steps that take place when the cash
register is booted to the image determined by its product ID:
CashRegister
No PXE Network Boot
Yes
Load kernel
Enable CashRegister
system on disk
Yes
Load kernel
Load boot initrd.gz
Run linuxrc
Load CashRegister
system
Enable CashRegister
system
105