Intel Extensible Firmware Interface - Manual (Page 56)

Extensible Firmware Interface Specification
2-16 12/01/02 Version 1.10
The leaf nodes in this tree structure are peripherals that perform some type of I/O. This could
include keyboards, displays, disks, network, etc. The nonleaf nodes are the buses that move data
between devices and buses, or between different bus types. Figure 2-5 shows a sample desktop
system with four buses and six devices.
OM13142
CPU
North
Bridge
USB
IDE
VGA
PCI-ISA
Bridge
PCI Bus
ISA Bus
1.44 MB
Floppy
Hard
Drive
CD-ROM
Keyboard
Mouse
IDE Bus
USB Bus
Bus Controller
Device Controller
Other
Figure 2-5. Desktop System
Figure 2-6 is an example of a more complex server system. The idea is to make the EFI Driver
Model simple and extensible so more complex systems like the one below can be described and
managed in the preboot environment. This system contains six buses and eight devices.
OM13143
CPU
North
Bridge
PCI-IBA
Bridge
USB
VGA
PCI-ISA
Bridge
PCI Bus
ISA Bus
1.44 MB
Floppy
KBD
MOUSE
USB Bus
IBA Bus
CPU
IBA-PCI
Bridge
SCSI
PCI Bus
Hard
Drive
Hard
Drive
Hard
Drive
Hard
Drive
Figure 2-6. Server System