8.3 Obtaining Services Tables

DXE drivers may consume the UEFI Boot Services, UEFI Runtime Services, and DXE Services. In addition, a DXE driver can also refer to UEFI System Table.

UEFI Boot Services, UEFI Runtime Services, and UEFI System Table are defined in the UEFI Specification. DXE Services are defined in the PI Specification.

DXE driver can retrieve these tables via global variables provided by the following library classes:

Table 11 Reference to Services Tables for DXE Drivers

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Global variable

Library Class

UEFI System Table

gST

UefiBootServicesTableLib

UEFI Boot Services Table

gBS

UefiBootServicesTableLib

UEFI Runtime Services Table

gRT

UefiRuntimeServicesTableLib

DXE Services Table

gDS

DxeServicesTableLib