Restoretpl() – Intel Extensible Firmware Interface User Manual
Page 115
Services — Boot Services
Version 1.10
12/01/02
5-17
RestoreTPL()
Summary
Restores a task’s priority level to its previous value.
Prototype
VOID
RestoreTPL (
IN EFI_TPL
OldTpl
)
Parameters
OldTpl
The previous task priority level to restore (the value from a
previous, matching call to
RaiseTPL()
). Type
EFI_TPL
is
defined in the
function description.
Description
The
RestoreTPL()
function restores a task’s priority level to its previous value. Calls to
RestoreTPL()
are matched with calls to
RaiseTPL()
.
NOTE
If
OldTpl
is above the current TPL level, then the system behavior is indeterminate.
Additionally, only
, and
may be used. All other values are reserved for use by the firmware; using
them will result in unpredictable behavior. Good coding practice dictates that all code should
execute at its lowest possible TPL level, and the use of TPL levels above
TPL_APPLICATION
must be minimized. Executing at TPL levels above
TPL_APPLICATION
for extended periods of
time may also result in unpredictable behavior.
Status Codes Returned
None.