MdePkg/Library/UefiSalLib/UefiSalLib.c

   1 /** @file
   2   SAL Library implementation built upon UEFI.
   3
   4   Copyright (c) 2007 - 2008, Intel Corporation All rights
   5   reserved. This program and the accompanying materials are
   6   licensed and made available under the terms and conditions of
   7   the BSD License which accompanies this distribution.  The full
   8   text of the license may be found at
   9   http://opensource.org/licenses/bsd-license.php
  10
  11   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  12   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  13
  14 **/
  15
  16 #include <PiDxe.h>
  17 #include <IndustryStandard/Sal.h>
  18
  19 #include <Library/SalLib.h>
  20 #include <Library/UefiLib.h>
  21 #include <Library/DebugLib.h>
  22
  23 #include <Guid/SalSystemTable.h>
  24
  25 EFI_PLABEL       mPlabel;
  26 SAL_PROC         mSalProcEntry;
  27
  28 /**
  29   Makes a SAL procedure call.
  30
  31   This is a wrapper function to make a SAL procedure call.
  32   No parameter checking is performed on the 8 input parameters,
  33   but there are some common rules that the caller should follow
  34   when making a SAL call.  Any address passed to SAL as buffers
  35   for return parameters must be 8-byte aligned.  Unaligned
  36   addresses may cause undefined results.  For those parameters
  37   defined as reserved or some fields defined as reserved must be
  38   zero filled or the invalid argument return value may be returned
  39   or undefined result may occur during the execution of the procedure.
  40   This function is only available on IPF.
  41
  42   @param  Index       The SAL procedure Index number
  43   @param  Arg2        The 2nd parameter for SAL procedure calls
  44   @param  Arg3        The 3rd parameter for SAL procedure calls
  45   @param  Arg4        The 4th parameter for SAL procedure calls
  46   @param  Arg5        The 5th parameter for SAL procedure calls
  47   @param  Arg6        The 6th parameter for SAL procedure calls
  48   @param  Arg7        The 7th parameter for SAL procedure calls
  49   @param  Arg8        The 8th parameter for SAL procedure calls
  50
  51   @return SAL returned registers.
  52
  53 **/
  54 SAL_RETURN_REGS
  55 EFIAPI
  56 SalCall (
  57   IN UINT64  Index,
  58   IN UINT64  Arg2,
  59   IN UINT64  Arg3,
  60   IN UINT64  Arg4,
  61   IN UINT64  Arg5,
  62   IN UINT64  Arg6,
  63   IN UINT64  Arg7,
  64   IN UINT64  Arg8
  65   )
  66 {
  67   //
  68   // mSalProcEntry is initialized in library constructor as SAL entry.
  69   //
  70   return mSalProcEntry(
  71            Index,
  72            Arg2,
  73            Arg3,
  74            Arg4,
  75            Arg5,
  76            Arg6,
  77            Arg7,
  78            Arg8
  79            );
  80
  81 }
  82
  83 /**
  84   The constructor function of UEFI SAL Lib.
  85
  86   The constructor function looks up the SAL System Table in the EFI System Configuration
  87   Table. Once the SAL System Table is found, the SAL Entry Point in the SAL System Table
  88   will be derived and stored inot a global variable for library usage.
  89   It will ASSERT() if the SAL System Table cannot be found or the data in the SAL System
  90   Table is not the valid data.
  91
  92   @param  ImageHandle   The firmware allocated handle for the EFI image.
  93   @param  SystemTable   A pointer to the EFI System Table.
  94
  95   @retval EFI_SUCCESS   The constructor always returns EFI_SUCCESS.
  96
  97 **/
  98 EFI_STATUS
  99 EFIAPI
 100 UefiSalLibConstructor (
 101   IN EFI_HANDLE        ImageHandle,
 102   IN EFI_SYSTEM_TABLE  *SystemTable
 103   )
 104 {
 105   EFI_STATUS                     Status;
 106   SAL_ST_ENTRY_POINT_DESCRIPTOR  *SalStEntryDes;
 107   SAL_SYSTEM_TABLE_HEADER        *SalSystemTable;
 108
 109   Status = EfiGetSystemConfigurationTable (
 110              &gEfiSalSystemTableGuid,
 111              (VOID **) &SalSystemTable
 112              );
 113
 114   ASSERT_EFI_ERROR (Status);
 115
 116   //
 117   // Move the SAL System Table point to the first Entry
 118   // Due to the SAL Entry is in ascending order with the Entry type,
 119   // the type 0 Entry should be the first if exist.
 120   //
 121   SalStEntryDes = (SAL_ST_ENTRY_POINT_DESCRIPTOR *)(SalSystemTable + 1);
 122
 123   //
 124   // Assure the SAL ENTRY Type is 0
 125   //
 126   ASSERT (SalStEntryDes->Type == EFI_SAL_ST_ENTRY_POINT);
 127
 128   mPlabel.EntryPoint = SalStEntryDes->SalProcEntry;
 129   mPlabel.GP = SalStEntryDes->SalGlobalDataPointer;
 130   //
 131   // Make sure the EntryPoint has the real value
 132   //
 133   ASSERT ((mPlabel.EntryPoint != 0) && (mPlabel.GP != 0));
 134
 135   mSalProcEntry = (SAL_PROC)((UINT64)&(mPlabel.EntryPoint));
 136
 137   return EFI_SUCCESS;
 138 }