mirror_edk2/UefiCpuPkg/Library/SmmCpuFeaturesLib/Ia32/SmmStmSupport.c
Michael D Kinney 0acd869796 UefiCpuPkg: Replace BSD License with BSD+Patent License
https://bugzilla.tianocore.org/show_bug.cgi?id=1373

Replace BSD 2-Clause License with BSD+Patent License.  This change is
based on the following emails:

  https://lists.01.org/pipermail/edk2-devel/2019-February/036260.html
  https://lists.01.org/pipermail/edk2-devel/2018-October/030385.html

RFCs with detailed process for the license change:

  V3: https://lists.01.org/pipermail/edk2-devel/2019-March/038116.html
  V2: https://lists.01.org/pipermail/edk2-devel/2019-March/037669.html
  V1: https://lists.01.org/pipermail/edk2-devel/2019-March/037500.html

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
2019-04-09 10:58:28 -07:00

78 lines
2.0 KiB
C

/** @file
SMM STM support functions
Copyright (c) 2015 - 2016, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include <PiSmm.h>
#include <Library/DebugLib.h>
#include "SmmStm.h"
///
/// Page Table Entry
///
#define IA32_PG_P BIT0
#define IA32_PG_RW BIT1
#define IA32_PG_PS BIT7
/**
Create 4G page table for STM.
4M Non-PAE page table in IA32 version.
@param PageTableBase The page table base in MSEG
**/
VOID
StmGen4GPageTable (
IN UINTN PageTableBase
)
{
UINTN Index;
UINT32 *Pte;
UINT32 Address;
Pte = (UINT32*)(UINTN)PageTableBase;
Address = 0;
for (Index = 0; Index < SIZE_4KB / sizeof (*Pte); Index++) {
*Pte = Address | IA32_PG_PS | IA32_PG_RW | IA32_PG_P;
Pte++;
Address += SIZE_4MB;
}
}
/**
This is SMM exception handle.
Consumed by STM when exception happen.
@param Context STM protection exception stack frame
@return the EBX value for STM reference.
EBX = 0: resume SMM guest using register state found on exception stack.
EBX = 1 to 0x0F: EBX contains a BIOS error code which the STM must record in the
TXT.ERRORCODE register and subsequently reset the system via
TXT.CMD.SYS_RESET. The value of the TXT.ERRORCODE register is calculated as
follows: TXT.ERRORCODE = (EBX & 0x0F) | STM_CRASH_BIOS_PANIC
EBX = 0x10 to 0xFFFFFFFF - reserved, do not use.
**/
UINT32
EFIAPI
SmmStmExceptionHandler (
IN OUT STM_PROTECTION_EXCEPTION_STACK_FRAME Context
)
{
// TBD - SmmStmExceptionHandler, record information
DEBUG ((DEBUG_ERROR, "SmmStmExceptionHandler ...\n"));
//
// Skip this instruction and continue;
//
Context.Ia32StackFrame->Rip += Context.Ia32StackFrame->VmcsExitInstructionLength;
return 0;
}