Intel Extensible Firmware Interface - Manual (Page 467)

Protocols — PCI Bus Support
Version 1.10 12/01/02 12-49
12.3.2 PCI Bus Drivers
A PCI Bus Driver manages PCI Host Bus Controllers that can contain one or more PCI Root
Bridges. Figure 12-9 shows an example of a desktop system that has one PCI Host Bus Controller
with one PCI Root Bridge.
OM13165
PCI Local Bus
Core Chipset Components
PCI Host Bus
PCI Root Bridge
Figure 12-9. PCI Host Bus Controller
The PCI Host Bus Controller in Figure 12-9 is abstracted in software with the PCI Root Bridge I/O
Protocol. A PCI Bus Driver will manage handles that contain this protocol. Figure 12-10 shows an
example device handle for a PCI Host Bus Controller. It contains a Device Path Protocol instance
and a PCI Root Bridge I/O Protocol Instance.
OM15221
Device Handle
EFI_DEVICE_PATH_PROTOCOL
EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL
Figure 12-10. Device Handle for a PCI Host Bus Controller