PeiStartupAllAPs()/PeiStartupThisAP() will send INIT-SIPI-SIPI to wakeup APs to execute AP function. However, some registers will be reset after APs received INIT IPI. We need to restore some registers (For example, CRx/DRx) manually after APs wakeup.
Cc: Feng Tian <[email protected]> Cc: Michael Kinney <[email protected]> Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Jeff Fan <[email protected]> --- UefiCpuPkg/CpuMpPei/CpuMpPei.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/UefiCpuPkg/CpuMpPei/CpuMpPei.c b/UefiCpuPkg/CpuMpPei/CpuMpPei.c index 53af948..ca48613 100644 --- a/UefiCpuPkg/CpuMpPei/CpuMpPei.c +++ b/UefiCpuPkg/CpuMpPei/CpuMpPei.c @@ -259,6 +259,11 @@ ApCFunction ( // Execute AP function if AP is not disabled // GetProcessorNumber (PeiCpuMpData, &ProcessorNumber); + // + // Restore AP's volatile registers saved + // + RestoreVolatileRegisters (&PeiCpuMpData->CpuData[ProcessorNumber].VolatileRegisters, TRUE); + if ((PeiCpuMpData->CpuData[ProcessorNumber].State != CpuStateDisabled) && (PeiCpuMpData->ApFunction != 0)) { PeiCpuMpData->CpuData[ProcessorNumber].State = CpuStateBusy; @@ -273,6 +278,11 @@ ApCFunction ( // InterlockedIncrement ((UINT32 *)&PeiCpuMpData->FinishedCount); + // + // Save AP volatile registers + // + SaveVolatileRegisters (&PeiCpuMpData->CpuData[ProcessorNumber].VolatileRegisters); + AsmCliHltLoop (); } -- 1.9.5.msysgit.0 _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
