1 files changed, 89 insertions, 0 deletions
diff --git a/roms/edk2/UefiCpuPkg/Library/SmmCpuFeaturesLib/X64/SmmStmSupport.c b/roms/edk2/UefiCpuPkg/Library/SmmCpuFeaturesLib/X64/SmmStmSupport.c
new file mode 100644
index 000000000..aacc1455a
--- /dev/null
+++ b/roms/edk2/UefiCpuPkg/Library/SmmCpuFeaturesLib/X64/SmmStmSupport.c
@@ -0,0 +1,89 @@
+/** @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.
+  2M PAE page table in X64 version.
+
+  @param PageTableBase        The page table base in MSEG
+
+**/
+VOID
+StmGen4GPageTable (
+  IN UINTN              PageTableBase
+  )
+{
+  UINTN                             Index;
+  UINTN                             SubIndex;
+  UINT64                            *Pde;
+  UINT64                            *Pte;
+  UINT64                            *Pml4;
+
+  Pml4 = (UINT64*)(UINTN)PageTableBase;
+  PageTableBase += SIZE_4KB;
+  *Pml4 = PageTableBase | IA32_PG_RW | IA32_PG_P;
+
+  Pde = (UINT64*)(UINTN)PageTableBase;
+  PageTableBase += SIZE_4KB;
+  Pte = (UINT64 *)(UINTN)PageTableBase;
+
+  for (Index = 0; Index < 4; Index++) {
+    *Pde = PageTableBase | IA32_PG_RW | IA32_PG_P;
+    Pde++;
+    PageTableBase += SIZE_4KB;
+
+    for (SubIndex = 0; SubIndex < SIZE_4KB / sizeof (*Pte); SubIndex++) {
+      *Pte = (((Index << 9) + SubIndex) << 21) | IA32_PG_PS | IA32_PG_RW | IA32_PG_P;
+      Pte++;
+    }
+  }
+}
+
+/**
+  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.X64StackFrame->Rip += Context.X64StackFrame->VmcsExitInstructionLength;
+
+  return 0;
+}