/** @file SMM STM support functions Copyright (c) 2015 - 2016, Intel Corporation. All rights reserved.
This program and the accompanying materials are licensed and made available under the terms and conditions of the BSD License which accompanies this distribution. The full text of the license may be found at http://opensource.org/licenses/bsd-license.php. THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. **/ #include #include #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; }