Intel Extensible Firmware Interface - Event, Timer, and Task Priority Functions; Event, Timer, and Task Priority Services

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 Boot 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.