[mirror_edk2.git] / MdePkg / Library / BaseLib / Ia32 / WriteCr4.c

/** @file\r
  AsmWriteCr4 function\r
\r
  Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>\r
  SPDX-License-Identifier: BSD-2-Clause-Patent\r
\r
**/\r
\r
/**\r
  Writes a value to Control Register 4 (CR4).\r
\r
  Writes and returns a new value to CR4. This function is only available on\r
  IA-32 and x64. This writes a 32-bit value on IA-32 and a 64-bit value on x64.\r
\r
  @param  Value The value to write to CR4.\r
\r
  @return The value written to CR4.\r
\r
**/\r
UINTN\r
EFIAPI\r
AsmWriteCr4 (\r
  UINTN  Value\r
  )\r
{\r
  _asm {\r
    mov     eax, Value\r
    _emit  0x0f  // mov  cr4, eax\r
    _emit  0x22\r
    _emit  0xE0\r
  }\r
}\r
Commit	Line	Data
e1f414b6	1	/** @file\r
	2	AsmWriteCr4 function\r
	3	\r
bb817c56	4	Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>\r
9344f092	5	SPDX-License-Identifier: BSD-2-Clause-Patent\r
e1f414b6	6	\r
	7	**/\r
	8	\r
42eedea9	9	/**\r
	10	Writes a value to Control Register 4 (CR4).\r
	11	\r
	12	Writes and returns a new value to CR4. This function is only available on\r
030cd1a2	13	IA-32 and x64. This writes a 32-bit value on IA-32 and a 64-bit value on x64.\r
42eedea9	14	\r
44b013bd	15	@param Value The value to write to CR4.\r
42eedea9	16	\r
	17	@return The value written to CR4.\r
	18	\r
	19	**/\r
e1f414b6	20	UINTN\r
	21	EFIAPI\r
	22	AsmWriteCr4 (\r
	23	UINTN Value\r
	24	)\r
	25	{\r
	26	_asm {\r
	27	mov eax, Value\r
	28	_emit 0x0f // mov cr4, eax\r
	29	_emit 0x22\r
	30	_emit 0xE0\r
	31	}\r
	32	}\r