Advanced Configuration and Power Interface Specification

*
* Intel Architecture SetSleepingState example
*/
ULONG
SetSystemSleeping (
IN ULONG NewState
)
{
PROCESSOR_CONTEXT Context;
ULONG PowerSeqeunce;
BOOLEAN FlushCaches;
USHORT SlpTyp;
Power and Performance Management
// Required environment: Executing on the system boot
// processor. All other processors stopped. Interrupts
// disabled. All Power Resources (and devices) are in
// corresponding device state to support NewState.
// Get h/w attributes for this system state
FlushCaches = SleepType[NewState].FlushCache;
SlpTyp = SleepType[NewState].SlpTyp & SLP_TYP_MASK;
_asm {
lea eax, OsResumeContext
push eax ; Build real mode handler the resume
push offset sp50 ; context, with eip = sp50
call SaveProcessorState
mov eax, ResumeVector ; set firmware’s resume vector
mov [eax], offset OsRealModeResumeCode
mov edx, PM1a_STS ; Make sure wake status is clear
mov ax, WAK_STS ; (cleared by asserting the bit
out dx, ax ; in the status register)
mov edx, PM1b_STS ;
out dx, ax ;
and eax, not SLP_TYP_MASK
or eax, SlpTyp ; set SLP_TYP
or ax, SLP_EN ; set SLP_EN
cmp FlushCaches, 0
jz short sp10 ; If needed, ensure no dirty data in
376 Hewlett-Packard/Intel/Microsoft/Phoenix/Toshiba