3Com e-PC c10/s10, User Manual

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3 3 8 8 C C h h a a p p t t e e r r 5 5
Once all desktop management agents complete execution the PC continues booting as usual
from its local hard drive. No user awareness or intervention is required.
IGURE HAT RE OES
In the past, client PCs using remoteboot ROMs could boot in only one of two ways: from a
server-based boot image file or from their hard drives. The Pre-OS approach is a hybrid; the
centrally-booted operating system is not the ultimate operating system but rather a
temporary environment created for executing management applications. Ultimately, clients
exit the Pre-OS environment and continue to boot from their local hard drive. Exiting the
Pre-OS environment is similar to executing a very soft Ctrl+Alt+Del where the PC continues
to load the OS on the hard disk.
This entire concept, which we call “Pre-OS managed booting”, or simply “Pre-OS”, is based
on existing MBA firmware capabilities, extended by any desktop management agents
contained in a special boot image file.
P P r r e e - - O O S S F F r r a a m m e e w w o o r r k k
The Pre-OS framework is essentially a DOS client with optional network connectivity. The
Pre-OS boot image is executed as a drive A: RAM disk residing in extended memory.
Most Pre-OS environments use a network connection to map network drives. Regular
network drivers may be loaded from the Pre-OS image, and this in no way affects the Pre-OS
environment or RAM drive operation.
If any network login is needed during the Pre-OS phase, it is typically as a guest user, so
that the user is not prompted to provide login name or password information.