Advanced Configuration and Power Interface Specification

Advanced Configuration and Power Interface Specification
Field
X Firmware Waking
Vector
Byte
Length
Byte
Offset
Description
8 24 64-bit physical address of OSPM’s Waking Vector.
Before transitioning the system into a global sleeping state,
OSPM fills in this field and the OSPM Flags field to describe the
waking vector. OSPM populates this field with the physical
memory address of an OS-specific wake function. During
POST, the platform firmware checks if the value of this field is
non-zero and if so transfers control to OSPM by jumping to this
address after creating the appropriate execution environment,
which must be configured as follows:
For 64-bit Itanium Processor Family (IPF) -based platforms:
Interrupts must be disabled
The processor must have psr.i set to 0. See the Intel® Itanium TM
Architecture Software Developer’s Manual for more information.
Memory address translation must be disabled
The processor must have psr.it, psr.dt, and psr.rt set to 0. See
the Intel® Itanium TM Architecture Software Developer’s Manual
for more information.
For IA 32 and x64 platforms, platform firmware is required to
support a 32 bit execution environment. Platform firmware can
additionally support a 64 bit execution environment. If platform
firmware supports a 64 bit execution environment, firmware
inspects the OSPM Flags during POST. If the 64BIT_WAKE_F
flag is set, the platform firmware creates a 64 bit execution
environment. Otherwise, the platform firmware creates a 32 bit
execution environment.
For 64 bit execution environment:
Interrupts must be disabled
EFLAGS.IF set to 0
Long mode enabled
Paging mode is enabled and physical memory for waking vector
is identity mapped (virtual address equals physical address)
Waking vector must be contained within one physical page
Selectors are set to be flat and are otherwise not used
For 32 bit execution environment:
Interrupts must be disabled
EFLAGS.IF set to 0
Memory address translation / paging must be disabled
4 GB flat address space for all segment registers
Version 1 32 2–Version of this table
Reserved 3 33 This value is zero.
OSPM Flags 4 36 OSPM enabled firmware control structure flags. Platform
firmware must initialize this field to zero. See Table 5-40 for a
description of the OSPM control structure feature flags.
Reserved 24 40 This value is zero.
132 April, 2015 Version 6.0