MdePkg/Include/Ppi/Stall.h

   1 /** @file
   2   This file declares Stall PPI.
   3
   4   This code abstracts the PEI core to provide Stall services.
   5
   6   Copyright (c) 2006 - 2007, Intel Corporation
   7   All rights reserved. This program and the accompanying materials
   8   are licensed and made available under the terms and conditions of the BSD License
   9   which accompanies this distribution.  The full text of the license may be found at
  10   http://opensource.org/licenses/bsd-license.php
  11
  12   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  13   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  14
  15   @par Revision Reference:
  16   This PPI is defined in PI.
  17   Version 1.00.
  18
  19 **/
  20
  21 #ifndef __STALL_PPI_H__
  22 #define __STALL_PPI_H__
  23
  24 #define EFI_PEI_STALL_PPI_GUID \
  25   { 0x1f4c6f90, 0xb06b, 0x48d8, {0xa2, 0x01, 0xba, 0xe5, 0xf1, 0xcd, 0x7d, 0x56 } }
  26
  27 typedef struct _EFI_PEI_STALL_PPI EFI_PEI_STALL_PPI;
  28
  29 /**
  30   The Stall() function provides a blocking stall for at least the number
  31   of microseconds stipulated in the final argument of the API.
  32
  33   @param  PeiServices    An indirect pointer to the PEI Services Table
  34                          published by the PEI Foundation.
  35   @param  This           Pointer to the local data for the interface.
  36   @param  Microseconds   Number of microseconds for which to stall.
  37
  38   @retval EFI_SUCCESS           The service provided at least the required delay.
  39
  40 **/
  41 typedef
  42 EFI_STATUS
  43 (EFIAPI *EFI_PEI_STALL) (
  44   IN EFI_PEI_SERVICES           **PeiServices,
  45   IN EFI_PEI_STALL_PPI          *This,
  46   IN UINTN                      Microseconds
  47   );
  48
  49 /**
  50   @par Ppi Description:
  51   This service provides a simple, blocking stall with platform-specific resolution.
  52
  53   @param Resolution
  54   The resolution in microseconds of the stall services.
  55
  56   @param Stall
  57   The actual stall procedure call.
  58
  59 **/
  60 struct _EFI_PEI_STALL_PPI {
  61   UINTN          Resolution;
  62   EFI_PEI_STALL  Stall;
  63 };
  64
  65 extern EFI_GUID gEfiPeiStallPpiGuid;
  66
  67 #endif