Getnextmonotoniccount() - Intel Extensible Firmware Interface Specification

3.8.4

GetNextMonotonicCount()

Summary
Returns a monotonically increasing count for the platform.
Prototype
EFI_STATUS
GetNextMonotonicCount (
OUT UINT64
);
Parameters
Count
Description
The
GetNextMonotonicCount()
then the last time the function was called.
The platform's monotonic counter is comprised of two parts: the high 32 bits and the low 32 bits.
The low 32 bit value is volatile and is reset to zero on every system reset. It is increased by 1 on
every call to GetNextMonotonicCount(). The high 32 bit value is non-volatile and is
increased by 1 on whenever the system resets or the low 32 bit counter overflows.
Status Codes Returned
EFI_SUCCESS
EFI_DEVICE_ERROR
EFI_INVALID_PARAMETER
Version 1.02
*Count
Pointer to returned value.
function returns a 64 bit value that is numerically larger
The next monotonic count was returned.
The device is not functioning properly.
One of the parameters has an invalid value.
12/12/00
Services
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