https://git.reactos.org/?p=reactos.git;a=commitdiff;h=99a6667bd911ad7dec92bfacdfa10cb702b37793
commit 99a6667bd911ad7dec92bfacdfa10cb702b37793 Author: Victor Perevertkin <[email protected]> AuthorDate: Sat Jan 15 04:15:05 2022 +0300 Commit: Victor Perevertkin <[email protected]> CommitDate: Tue Jan 25 02:12:33 2022 +0300 [NTOS:KE] Remove all checks for x87 not being present --- ntoskrnl/ke/i386/cpu.c | 140 +++++--------------------- ntoskrnl/ke/i386/exp.c | 245 ++++++++++++++++++--------------------------- ntoskrnl/ke/i386/kiinit.c | 68 +++---------- ntoskrnl/ke/i386/thrdini.c | 33 ++---- 4 files changed, 151 insertions(+), 335 deletions(-) diff --git a/ntoskrnl/ke/i386/cpu.c b/ntoskrnl/ke/i386/cpu.c index 03bd33d465b..e627efe228a 100644 --- a/ntoskrnl/ke/i386/cpu.c +++ b/ntoskrnl/ke/i386/cpu.c @@ -24,7 +24,7 @@ UCHAR KiNMITSS[KTSS_IO_MAPS]; ULONG KeI386CpuType; ULONG KeI386CpuStep; ULONG KiFastSystemCallDisable = 0; -ULONG KeI386NpxPresent = 0; +ULONG KeI386NpxPresent = TRUE; ULONG KiMXCsrMask = 0; ULONG MxcsrFeatureMask = 0; ULONG KeI386XMMIPresent = 0; @@ -90,66 +90,30 @@ VOID NTAPI KiSetProcessorType(VOID) { - ULONG EFlags, NewEFlags; CPU_INFO CpuInfo; ULONG Stepping, Type; - /* Start by assuming no CPUID data */ - KeGetCurrentPrcb()->CpuID = 0; - - /* Save EFlags */ - EFlags = __readeflags(); - - /* XOR out the ID bit and update EFlags */ - NewEFlags = EFlags ^ EFLAGS_ID; - __writeeflags(NewEFlags); - - /* Get them back and see if they were modified */ - NewEFlags = __readeflags(); - if (NewEFlags != EFlags) - { - /* The modification worked, so CPUID exists. Set the ID Bit again. */ - EFlags |= EFLAGS_ID; - __writeeflags(EFlags); - - /* Peform CPUID 0 to see if CPUID 1 is supported */ - KiCpuId(&CpuInfo, 0); - if (CpuInfo.Eax > 0) - { - /* Do CPUID 1 now */ - KiCpuId(&CpuInfo, 1); - - /* - * Get the Stepping and Type. The stepping contains both the - * Model and the Step, while the Type contains the returned Type. - * We ignore the family. - * - * For the stepping, we convert this: zzzzzzxy into this: x0y - */ - Stepping = CpuInfo.Eax & 0xF0; - Stepping <<= 4; - Stepping += (CpuInfo.Eax & 0xFF); - Stepping &= 0xF0F; - Type = CpuInfo.Eax & 0xF00; - Type >>= 8; - - /* Save them in the PRCB */ - KeGetCurrentPrcb()->CpuID = TRUE; - KeGetCurrentPrcb()->CpuType = (UCHAR)Type; - KeGetCurrentPrcb()->CpuStep = (USHORT)Stepping; - } - else - { - DPRINT1("CPUID Support lacking\n"); - } - } - else - { - DPRINT1("CPUID Support lacking\n"); - } + /* Do CPUID 1 now */ + KiCpuId(&CpuInfo, 1); - /* Restore EFLAGS */ - __writeeflags(EFlags); + /* + * Get the Stepping and Type. The stepping contains both the + * Model and the Step, while the Type contains the returned Type. + * We ignore the family. + * + * For the stepping, we convert this: zzzzzzxy into this: x0y + */ + Stepping = CpuInfo.Eax & 0xF0; + Stepping <<= 4; + Stepping += (CpuInfo.Eax & 0xFF); + Stepping &= 0xF0F; + Type = CpuInfo.Eax & 0xF00; + Type >>= 8; + + /* Save them in the PRCB */ + KeGetCurrentPrcb()->CpuID = TRUE; + KeGetCurrentPrcb()->CpuType = (UCHAR)Type; + KeGetCurrentPrcb()->CpuStep = (USHORT)Stepping; } CODE_SEG("INIT") @@ -160,10 +124,6 @@ KiGetCpuVendor(VOID) PKPRCB Prcb = KeGetCurrentPrcb(); CPU_INFO CpuInfo; - /* Assume no Vendor ID and fail if no CPUID Support. */ - Prcb->VendorString[0] = 0; - if (!Prcb->CpuID) return 0; - /* Get the Vendor ID */ KiCpuId(&CpuInfo, 0); @@ -465,7 +425,6 @@ NTAPI KiGetCacheInformation(VOID) { PKIPCR Pcr = (PKIPCR)KeGetPcr(); - ULONG Vendor; CPU_INFO CpuInfo; ULONG CacheRequests = 0, i; ULONG CurrentRegister; @@ -476,12 +435,8 @@ KiGetCacheInformation(VOID) /* Set default L2 size */ Pcr->SecondLevelCacheSize = 0; - /* Get the Vendor ID and make sure we support CPUID */ - Vendor = KiGetCpuVendor(); - if (!Vendor) return; - /* Check the Vendor ID */ - switch (Vendor) + switch (KiGetCpuVendor()) { /* Handle Intel case */ case CPU_INTEL: @@ -1158,47 +1113,6 @@ KiSaveProcessorState(IN PKTRAP_FRAME TrapFrame, KiSaveProcessorControlState(&Prcb->ProcessorState); } -CODE_SEG("INIT") -BOOLEAN -NTAPI -KiIsNpxPresent(VOID) -{ - ULONG Cr0; - USHORT Magic; - - /* Set magic */ - Magic = 0xFFFF; - - /* Read CR0 and mask out FPU flags */ - Cr0 = __readcr0() & ~(CR0_MP | CR0_TS | CR0_EM | CR0_ET); - - /* Store on FPU stack */ -#ifdef _MSC_VER - __asm fninit; - __asm fnstsw Magic; -#else - asm volatile ("fninit;" "fnstsw %0" : "+m"(Magic)); -#endif - - /* Magic should now be cleared */ - if (Magic & 0xFF) - { - /* You don't have an FPU -- enable emulation for now */ - __writecr0(Cr0 | CR0_EM | CR0_TS); - return FALSE; - } - - /* You have an FPU, enable it */ - Cr0 |= CR0_ET; - - /* Enable INT 16 on 486 and higher */ - if (KeGetCurrentPrcb()->CpuType >= 3) Cr0 |= CR0_NE; - - /* Set FPU state */ - __writecr0(Cr0 | CR0_EM | CR0_TS); - return TRUE; -} - CODE_SEG("INIT") BOOLEAN NTAPI @@ -1208,8 +1122,8 @@ KiIsNpxErrataPresent(VOID) INT ErrataPresent; ULONG Cr0; - /* Disable interrupts */ - _disable(); + /* Interrupts have to be disabled here. */ + ASSERT(!(__readeflags() & EFLAGS_INTERRUPT_MASK)); /* Read CR0 and remove FPU flags */ Cr0 = __readcr0(); @@ -1247,9 +1161,6 @@ KiIsNpxErrataPresent(VOID) /* Restore CR0 */ __writecr0(Cr0); - /* Enable interrupts */ - _enable(); - /* Return if there's an errata */ return ErrataPresent != 0; } @@ -1370,9 +1281,6 @@ KeSaveFloatingPointState(OUT PKFLOATING_SAVE Save) ASSERT(KeGetCurrentIrql() <= DISPATCH_LEVEL); UNIMPLEMENTED_ONCE; - /* check if we are doing software emulation */ - if (!KeI386NpxPresent) return STATUS_ILLEGAL_FLOAT_CONTEXT; - FpState = ExAllocatePool(NonPagedPool, sizeof (FNSAVE_FORMAT)); if (!FpState) return STATUS_INSUFFICIENT_RESOURCES; diff --git a/ntoskrnl/ke/i386/exp.c b/ntoskrnl/ke/i386/exp.c index a64faa1d60c..7ed82f72017 100644 --- a/ntoskrnl/ke/i386/exp.c +++ b/ntoskrnl/ke/i386/exp.c @@ -434,30 +434,25 @@ KeContextToTrapFrame(IN PCONTEXT Context, /* Get the FX Area */ FxSaveArea = (PFX_SAVE_AREA)(TrapFrame + 1); - /* Check if NPX is present */ - if (KeI386NpxPresent) - { - /* Flush the NPX State */ - KiFlushNPXState(NULL); + /* Flush the NPX State */ + KiFlushNPXState(NULL); - /* Copy the FX State */ - RtlCopyMemory(&FxSaveArea->U.FxArea, - &Context->ExtendedRegisters[0], - MAXIMUM_SUPPORTED_EXTENSION); + /* Copy the FX State */ + RtlCopyMemory(&FxSaveArea->U.FxArea, + &Context->ExtendedRegisters[0], + MAXIMUM_SUPPORTED_EXTENSION); - /* Remove reserved bits from MXCSR */ - FxSaveArea->U.FxArea.MXCsr &= KiMXCsrMask; + /* Remove reserved bits from MXCSR */ + FxSaveArea->U.FxArea.MXCsr &= KiMXCsrMask; - /* Mask out any invalid flags */ - FxSaveArea->Cr0NpxState &= ~(CR0_EM | CR0_MP | CR0_TS); + /* Mask out any invalid flags */ + FxSaveArea->Cr0NpxState &= ~(CR0_EM | CR0_MP | CR0_TS); - /* Check if this is a VDM app */ - if (PsGetCurrentProcess()->VdmObjects) - { - /* Allow the EM flag */ - FxSaveArea->Cr0NpxState |= Context->FloatSave.Cr0NpxState & - (CR0_EM | CR0_MP); - } + /* Check if this is a VDM app */ + if (PsGetCurrentProcess()->VdmObjects) + { + /* Allow the EM flag */ + FxSaveArea->Cr0NpxState |= Context->FloatSave.Cr0NpxState & (CR0_EM | CR0_MP); } } @@ -468,88 +463,63 @@ KeContextToTrapFrame(IN PCONTEXT Context, /* Get the FX Area */ FxSaveArea = (PFX_SAVE_AREA)(TrapFrame + 1); - /* Check if NPX is present */ - if (KeI386NpxPresent) - { - /* Flush the NPX State */ - KiFlushNPXState(NULL); + /* Flush the NPX State */ + KiFlushNPXState(NULL); - /* Check if we have Fxsr support */ - if (KeI386FxsrPresent) - { - /* Convert the Fn Floating Point state to Fx */ - FxSaveArea->U.FxArea.ControlWord = - (USHORT)Context->FloatSave.ControlWord; - FxSaveArea->U.FxArea.StatusWord = - (USHORT)Context->FloatSave.StatusWord; - FxSaveArea->U.FxArea.TagWord = - KiTagWordFnsaveToFxsave((USHORT)Context->FloatSave.TagWord); - FxSaveArea->U.FxArea.ErrorOpcode = - (USHORT)((Context->FloatSave.ErrorSelector >> 16) & 0xFFFF); - FxSaveArea->U.FxArea.ErrorOffset = - Context->FloatSave.ErrorOffset; - FxSaveArea->U.FxArea.ErrorSelector = - Context->FloatSave.ErrorSelector & 0xFFFF; - FxSaveArea->U.FxArea.DataOffset = - Context->FloatSave.DataOffset; - FxSaveArea->U.FxArea.DataSelector = - Context->FloatSave.DataSelector; - - /* Clear out the Register Area */ - RtlZeroMemory(&FxSaveArea->U.FxArea.RegisterArea[0], - SIZE_OF_FX_REGISTERS); - - /* Loop the 8 floating point registers */ - for (i = 0; i < 8; i++) - { - /* Copy from Fn to Fx */ - RtlCopyMemory(FxSaveArea->U.FxArea.RegisterArea + (i * 16), - Context->FloatSave.RegisterArea + (i * 10), - 10); - } - } - else + /* Check if we have Fxsr support */ + if (KeI386FxsrPresent) + { + /* Convert the Fn Floating Point state to Fx */ + FxSaveArea->U.FxArea.ControlWord = (USHORT)Context->FloatSave.ControlWord; + FxSaveArea->U.FxArea.StatusWord = (USHORT)Context->FloatSave.StatusWord; + FxSaveArea->U.FxArea.TagWord = + KiTagWordFnsaveToFxsave((USHORT)Context->FloatSave.TagWord); + FxSaveArea->U.FxArea.ErrorOpcode = + (USHORT)((Context->FloatSave.ErrorSelector >> 16) & 0xFFFF); + FxSaveArea->U.FxArea.ErrorOffset = Context->FloatSave.ErrorOffset; + FxSaveArea->U.FxArea.ErrorSelector = Context->FloatSave.ErrorSelector & 0xFFFF; + FxSaveArea->U.FxArea.DataOffset = Context->FloatSave.DataOffset; + FxSaveArea->U.FxArea.DataSelector = Context->FloatSave.DataSelector; + + /* Clear out the Register Area */ + RtlZeroMemory(&FxSaveArea->U.FxArea.RegisterArea[0], SIZE_OF_FX_REGISTERS); + + /* Loop the 8 floating point registers */ + for (i = 0; i < 8; i++) { - /* Copy the structure */ - FxSaveArea->U.FnArea.ControlWord = Context->FloatSave. - ControlWord; - FxSaveArea->U.FnArea.StatusWord = Context->FloatSave. - StatusWord; - FxSaveArea->U.FnArea.TagWord = Context->FloatSave.TagWord; - FxSaveArea->U.FnArea.ErrorOffset = Context->FloatSave. - ErrorOffset; - FxSaveArea->U.FnArea.ErrorSelector = Context->FloatSave. - ErrorSelector; - FxSaveArea->U.FnArea.DataOffset = Context->FloatSave. - DataOffset; - FxSaveArea->U.FnArea.DataSelector = Context->FloatSave. - DataSelector; - - /* Loop registers */ - for (i = 0; i < SIZE_OF_80387_REGISTERS; i++) - { - /* Copy registers */ - FxSaveArea->U.FnArea.RegisterArea[i] = - Context->FloatSave.RegisterArea[i]; - } + /* Copy from Fn to Fx */ + RtlCopyMemory(FxSaveArea->U.FxArea.RegisterArea + (i * 16), + Context->FloatSave.RegisterArea + (i * 10), + 10); } + } + else + { + /* Copy the structure */ + FxSaveArea->U.FnArea.ControlWord = Context->FloatSave.ControlWord; + FxSaveArea->U.FnArea.StatusWord = Context->FloatSave.StatusWord; + FxSaveArea->U.FnArea.TagWord = Context->FloatSave.TagWord; + FxSaveArea->U.FnArea.ErrorOffset = Context->FloatSave.ErrorOffset; + FxSaveArea->U.FnArea.ErrorSelector = Context->FloatSave.ErrorSelector; + FxSaveArea->U.FnArea.DataOffset = Context->FloatSave.DataOffset; + FxSaveArea->U.FnArea.DataSelector = Context->FloatSave.DataSelector; - /* Mask out any invalid flags */ - FxSaveArea->Cr0NpxState &= ~(CR0_EM | CR0_MP | CR0_TS); - - /* Check if this is a VDM app */ - if (PsGetCurrentProcess()->VdmObjects) + /* Loop registers */ + for (i = 0; i < SIZE_OF_80387_REGISTERS; i++) { - /* Allow the EM flag */ - FxSaveArea->Cr0NpxState |= Context->FloatSave.Cr0NpxState & - (CR0_EM | CR0_MP); + /* Copy registers */ + FxSaveArea->U.FnArea.RegisterArea[i] = Context->FloatSave.RegisterArea[i]; } } - else + + /* Mask out any invalid flags */ + FxSaveArea->Cr0NpxState &= ~(CR0_EM | CR0_MP | CR0_TS); + + /* Check if this is a VDM app */ + if (PsGetCurrentProcess()->VdmObjects) { - /* FIXME: Handle FPU Emulation */ - //ASSERT(FALSE); - UNIMPLEMENTED; + /* Allow the EM flag */ + FxSaveArea->Cr0NpxState |= Context->FloatSave.Cr0NpxState & (CR0_EM | CR0_MP); } } @@ -698,17 +668,13 @@ KeTrapFrameToContext(IN PKTRAP_FRAME TrapFrame, /* Get the FX Save Area */ FxSaveArea = (PFX_SAVE_AREA)(TrapFrame + 1); - /* Make sure NPX is present */ - if (KeI386NpxPresent) - { - /* Flush the NPX State */ - KiFlushNPXState(NULL); + /* Flush the NPX State */ + KiFlushNPXState(NULL); - /* Copy the registers */ - RtlCopyMemory(&Context->ExtendedRegisters[0], - &FxSaveArea->U.FxArea, - MAXIMUM_SUPPORTED_EXTENSION); - } + /* Copy the registers */ + RtlCopyMemory(&Context->ExtendedRegisters[0], + &FxSaveArea->U.FxArea, + MAXIMUM_SUPPORTED_EXTENSION); } /* Handle Floating Point */ @@ -718,49 +684,38 @@ KeTrapFrameToContext(IN PKTRAP_FRAME TrapFrame, /* Get the FX Save Area */ FxSaveArea = (PFX_SAVE_AREA)(TrapFrame + 1); - /* Make sure we have an NPX */ - if (KeI386NpxPresent) - { - /* Check if we have Fxsr support */ - if (KeI386FxsrPresent) - { - /* Align the floating area to 16-bytes */ - FloatSaveArea = (FLOATING_SAVE_AREA*) - ((ULONG_PTR)&FloatSaveBuffer.UnalignedArea &~ 0xF); - - /* Get the State */ - KiFlushNPXState(FloatSaveArea); - } - else - { - /* We don't, use the FN area and flush the NPX State */ - FloatSaveArea = (FLOATING_SAVE_AREA*)&FxSaveArea->U.FnArea; - KiFlushNPXState(NULL); - } + /* Check if we have Fxsr support */ + if (KeI386FxsrPresent) + { + /* Align the floating area to 16-bytes */ + FloatSaveArea = (FLOATING_SAVE_AREA*)((ULONG_PTR)&FloatSaveBuffer.UnalignedArea &~ 0xF); - /* Copy structure */ - Context->FloatSave.ControlWord = FloatSaveArea->ControlWord; - Context->FloatSave.StatusWord = FloatSaveArea->StatusWord; - Context->FloatSave.TagWord = FloatSaveArea->TagWord; - Context->FloatSave.ErrorOffset = FloatSaveArea->ErrorOffset; - Context->FloatSave.ErrorSelector = FloatSaveArea->ErrorSelector; - Context->FloatSave.DataOffset = FloatSaveArea->DataOffset; - Context->FloatSave.DataSelector = FloatSaveArea->DataSelector; - Context->FloatSave.Cr0NpxState = FxSaveArea->Cr0NpxState; + /* Get the State */ + KiFlushNPXState(FloatSaveArea); + } + else + { + /* We don't, use the FN area and flush the NPX State */ + FloatSaveArea = (FLOATING_SAVE_AREA*)&FxSaveArea->U.FnArea; + KiFlushNPXState(NULL); + } - /* Loop registers */ - for (i = 0; i < SIZE_OF_80387_REGISTERS; i++) - { - /* Copy them */ - Context->FloatSave.RegisterArea[i] = - FloatSaveArea->RegisterArea[i]; - } - } - else - { - /* FIXME: Handle Emulation */ - ASSERT(FALSE); - } + /* Copy structure */ + Context->FloatSave.ControlWord = FloatSaveArea->ControlWord; + Context->FloatSave.StatusWord = FloatSaveArea->StatusWord; + Context->FloatSave.TagWord = FloatSaveArea->TagWord; + Context->FloatSave.ErrorOffset = FloatSaveArea->ErrorOffset; + Context->FloatSave.ErrorSelector = FloatSaveArea->ErrorSelector; + Context->FloatSave.DataOffset = FloatSaveArea->DataOffset; + Context->FloatSave.DataSelector = FloatSaveArea->DataSelector; + Context->FloatSave.Cr0NpxState = FxSaveArea->Cr0NpxState; + + /* Loop registers */ + for (i = 0; i < SIZE_OF_80387_REGISTERS; i++) + { + /* Copy them */ + Context->FloatSave.RegisterArea[i] = FloatSaveArea->RegisterArea[i]; + } } /* Handle debug registers */ diff --git a/ntoskrnl/ke/i386/kiinit.c b/ntoskrnl/ke/i386/kiinit.c index 10889c0195c..7f0651e260a 100644 --- a/ntoskrnl/ke/i386/kiinit.c +++ b/ntoskrnl/ke/i386/kiinit.c @@ -85,58 +85,6 @@ KiInitMachineDependent(VOID) /* Check for PAT support and enable it */ if (KeFeatureBits & KF_PAT) KiInitializePAT(); - /* Assume no errata for now */ - SharedUserData->ProcessorFeatures[PF_FLOATING_POINT_PRECISION_ERRATA] = 0; - - /* Check if we have an NPX */ - if (KeI386NpxPresent) - { - /* Loop every CPU */ - i = KeActiveProcessors; - for (Affinity = 1; i; Affinity <<= 1) - { - /* Check if this is part of the set */ - if (i & Affinity) - { - /* Run on this CPU */ - i &= ~Affinity; - KeSetSystemAffinityThread(Affinity); - - /* Detect FPU errata */ - if (KiIsNpxErrataPresent()) - { - /* Disable NPX support */ - KeI386NpxPresent = FALSE; - SharedUserData-> - ProcessorFeatures[PF_FLOATING_POINT_PRECISION_ERRATA] = - TRUE; - break; - } - } - } - } - - /* If there's no NPX, then we're emulating the FPU */ - SharedUserData->ProcessorFeatures[PF_FLOATING_POINT_EMULATED] = - !KeI386NpxPresent; - - /* Check if there's no NPX, so that we can disable associated features */ - if (!KeI386NpxPresent) - { - /* Remove NPX-related bits */ - KeFeatureBits &= ~(KF_XMMI64 | KF_XMMI | KF_FXSR | KF_MMX); - - /* Disable kernel flags */ - KeI386FxsrPresent = KeI386XMMIPresent = FALSE; - - /* Disable processor features that might've been set until now */ - SharedUserData->ProcessorFeatures[PF_FLOATING_POINT_PRECISION_ERRATA] = - SharedUserData->ProcessorFeatures[PF_XMMI64_INSTRUCTIONS_AVAILABLE] = - SharedUserData->ProcessorFeatures[PF_XMMI_INSTRUCTIONS_AVAILABLE] = - SharedUserData->ProcessorFeatures[PF_3DNOW_INSTRUCTIONS_AVAILABLE] = - SharedUserData->ProcessorFeatures[PF_MMX_INSTRUCTIONS_AVAILABLE] = 0; - } - /* Check for CR4 support */ if (KeFeatureBits & KF_CR4) { @@ -459,6 +407,21 @@ KiVerifyCpuFeatures(PKPRCB Prcb) KeBugCheckEx(UNSUPPORTED_PROCESSOR, 0x2, 0x00000001, 0, 0); } + // Set up FPU-related CR0 flags. + ULONG Cr0 = __readcr0(); + // Disable emulation and monitoring. + Cr0 &= ~(CR0_EM | CR0_MP); + // Enable FPU exceptions. + Cr0 |= CR0_NE; + + __writecr0(Cr0); + + // Check for Pentium FPU bug. + if (KiIsNpxErrataPresent()) + { + KeBugCheckEx(UNSUPPORTED_PROCESSOR, 0x2, 0x00000001, 0, 0); + } + // 5. Save feature bits. Prcb->FeatureBits = FeatureBits; } @@ -590,6 +553,7 @@ KiInitializeKernel(IN PKPROCESS InitProcess, ((PETHREAD)InitThread)->ThreadsProcess = (PEPROCESS)InitProcess; /* Set basic CPU Features that user mode can read */ + SharedUserData->ProcessorFeatures[PF_FLOATING_POINT_PRECISION_ERRATA] = FALSE; SharedUserData->ProcessorFeatures[PF_MMX_INSTRUCTIONS_AVAILABLE] = (KeFeatureBits & KF_MMX) ? TRUE: FALSE; SharedUserData->ProcessorFeatures[PF_COMPARE_EXCHANGE_DOUBLE] = diff --git a/ntoskrnl/ke/i386/thrdini.c b/ntoskrnl/ke/i386/thrdini.c index 11bf02de2fb..ae9a599a8e2 100644 --- a/ntoskrnl/ke/i386/thrdini.c +++ b/ntoskrnl/ke/i386/thrdini.c @@ -152,28 +152,17 @@ KiInitializeContextThread(IN PKTHREAD Thread, Context->FloatSave.DataSelector = 0; } - /* Check if the CPU has NPX */ - if (KeI386NpxPresent) - { - /* Set an intial NPX State */ - Context->FloatSave.Cr0NpxState = 0; - FxSaveArea->Cr0NpxState = 0; - FxSaveArea->NpxSavedCpu = 0; - - /* Now set the context flags depending on XMM support */ - ContextFlags |= (KeI386FxsrPresent) ? CONTEXT_EXTENDED_REGISTERS : - CONTEXT_FLOATING_POINT; - - /* Set the Thread's NPX State */ - Thread->NpxState = NPX_STATE_NOT_LOADED; - Thread->Header.NpxIrql = PASSIVE_LEVEL; - } - else - { - /* We'll use emulation */ - FxSaveArea->Cr0NpxState = CR0_EM; - Thread->NpxState = NPX_STATE_NOT_LOADED &~ CR0_MP; - } + /* Set an intial NPX State */ + Context->FloatSave.Cr0NpxState = 0; + FxSaveArea->Cr0NpxState = 0; + FxSaveArea->NpxSavedCpu = 0; + + /* Now set the context flags depending on XMM support */ + ContextFlags |= (KeI386FxsrPresent) ? CONTEXT_EXTENDED_REGISTERS : CONTEXT_FLOATING_POINT; + + /* Set the Thread's NPX State */ + Thread->NpxState = NPX_STATE_NOT_LOADED; + Thread->Header.NpxIrql = PASSIVE_LEVEL; /* Disable any debug registers */ Context->ContextFlags &= ~CONTEXT_DEBUG_REGISTERS;
