[mirror_edk2.git] / MdePkg / Library / BaseLib / Ia32 / ReadDr4.c

/** @file\r
  AsmReadDr4 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
\r
\r
/**\r
  Reads the current value of Debug Register 4 (DR4).\r
\r
  Reads and returns the current value of DR4. This function is only available\r
  on IA-32 and x64. This returns a 32-bit value on IA-32 and a 64-bit value on\r
  x64.\r
\r
  @return The value of Debug Register 4 (DR4).\r
\r
**/\r
UINTN\r
EFIAPI\r
AsmReadDr4 (\r
  VOID\r
  )\r
{\r
  __asm {\r
    _emit  0x0f\r
    _emit  0x21\r
    _emit  0xe0\r
  }\r
}\r
\r
Commit	Line	Data
	1	/** @file\r
	2	AsmReadDr4 function\r
	3	\r
	4	Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>\r
	5	SPDX-License-Identifier: BSD-2-Clause-Patent\r
	6	\r
	7	**/\r
	8	\r
	9	\r
	10	\r
	11	\r
	12	/**\r
	13	Reads the current value of Debug Register 4 (DR4).\r
	14	\r
	15	Reads and returns the current value of DR4. This function is only available\r
	16	on IA-32 and x64. This returns a 32-bit value on IA-32 and a 64-bit value on\r
	17	x64.\r
	18	\r
	19	@return The value of Debug Register 4 (DR4).\r
	20	\r
	21	**/\r
	22	UINTN\r
	23	EFIAPI\r
	24	AsmReadDr4 (\r
	25	VOID\r
	26	)\r
	27	{\r
	28	__asm {\r
	29	_emit 0x0f\r
	30	_emit 0x21\r
	31	_emit 0xe0\r
	32	}\r
	33	}\r
	34	\r