Intel Extensible Firmware Interface - page 106

Extensible Firmware Interface Specification
88 12/12/00 Version 1.02
3.6.2 SetTime()
Summary
Sets the current local time and date information.
Prototype
EFI_STATUS
SetTime (
IN EFI_TIME *Time
);
Parameters
Time A pointer to the current time. Type EFI_TIME is defined in
Section 3.6.1. Full error checking is performed on the different fields of
the EFI_TIME structure (refer to the EFI_TIME definition on page 85
for full details), and EFI_INVALID_PARAMETER is returned if any
field is out of range.
Description
The SetTime() function sets the real time clock device to the supplied time, and records the
current time zone and daylight savings time information. The SetTime() function is not allowed
to loop based on the current time. For example, if the device does not support a hardware reset for
the sub-resolution time, the code is not to implement the feature by waiting for the time to wrap.
During runtime, if a PC-AT CMOS device is present in the platform the caller must synchronize
access to the device before calling SetTime().
Status Codes Returned
EFI_SUCCESS The operation completed successfully.
EFI_INVALID_PARAMETER A time field is out of range.
EFI_DEVICE_ERROR The time could not be set due to a hardware error.