Intel Extensible Firmware Interface User Manual
Page 472

Extensible Firmware Interface Specification
12-54
12/01/02
Version 1.10
function, so the
Stop()
function completes any
outstanding transactions to the PCI Controller and removes the protocol interfaces that were
installed in
Start()
. Figure 12-14 shows the device handle for a PCI Controller before and after
Start()
is called. In this example, a PCI Device Driver is adding the Block I/O Protocol to the
device handle for the PCI Controller. It is also a PCI Device Driver’s responsibility to disable the
I/O, Memory, and Bus Master decodes by calling
OM13168
PCI Controller Device Handle
EFI_DEVICE_PATH_PROTOCOL
EFI_PCI_I/O_PROTOCOL
EFI_BLOCK_I/O_PROTOCOL
PCI Controller Device Handle
EFI_DEVICE_PATH_PROTOCOL
EFI_PCI_I/O_PROTOCOL
Stop() : Closes PCI I/O
Start() : Opens PCI I/O
Installed by Start()
Uninstalled by Stop()
Figure 12-14. Connecting a PCI Device Driver