Extensible Firmware Interface Specification
26 12/12/00 Version 1.02
The rest of this chapter discusses individual functions. Global boot services functions fall into
these categories:
• Event, Timer, and Task Priority Services (Section 3.1)
• Memory Allocation Services (Section 3.2)
• Protocol Handler Services (Section 3.3)
• Image Services (Section 3.4)
• Miscellaneous Services (Section 3.8)
Runtime Services fall into these categories:
• Variable Services (Section 3.5)
• Time Services (Section 3.6)
• Virtual Memory Services (Section 3.7)
• Miscellaneous Services (Section 3.8)
3.1 Event, Timer, and Task Priority Services
The functions that make up the Event, Timer, and Task Priority Services are used during pre-boot
to create, close, signal, and wait for events; to set timers; and to raise and restore task priority
levels. See Table 3-1.
Table 3-1. Event, Timer, and Task Priority Functions
Name Type Description
CreateEvent Boot Creates a general-purpose event structure.
CloseEvent Boot Closes and frees an event structure.
SignalEvent Boot Signals an event.
WaitForEvent Boot Stops execution until an event is signaled.
CheckEvent Boo t Checks whether an event is in the signaled state.
SetTimer Boot Sets an event to be signaled at a particular time.
RaiseTPL Boot Raises the task priority level.
RestoreTPL Boot Restores/lowers the task priority level.