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Diffstat (limited to 'MdePkg/Library/UefiPalLib/UefiPalLib.c')
| -rw-r--r-- | MdePkg/Library/UefiPalLib/UefiPalLib.c | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/MdePkg/Library/UefiPalLib/UefiPalLib.c b/MdePkg/Library/UefiPalLib/UefiPalLib.c new file mode 100644 index 0000000000000..c4c465a90393b --- /dev/null +++ b/MdePkg/Library/UefiPalLib/UefiPalLib.c @@ -0,0 +1,127 @@ +/** @file + PAL Library implementation retrieving the PAL Entry Point from the SAL System Table + register in the EFI System Confguration Table. + + Copyright (c) 2007 - 2008, Intel Corporation. All rights reserved.<BR> + 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 <PiDxe.h> + +#include <IndustryStandard/Sal.h> +#include <Library/UefiLib.h> +#include <Library/BaseLib.h> +#include <Library/DebugLib.h> + +#include <Guid/SalSystemTable.h> + +UINT64 mPalProcEntry; + +/** + Makes a PAL procedure call. + + This is a wrapper function to make a PAL procedure call. Based on the Index value, + this API will make static or stacked PAL call. Architected procedures may be designated + as required or optional. If a PAL procedure is specified as optional, a unique return + code of 0xFFFFFFFFFFFFFFFF is returned in the Status field of the PAL_CALL_RETURN structure. + This indicates that the procedure is not present in this PAL implementation. It is the + caller's responsibility to check for this return code after calling any optional PAL + procedure. No parameter checking is performed on the 4 input parameters, but there are + some common rules that the caller should follow when making a PAL call. Any address + passed to PAL as buffers for return parameters must be 8-byte aligned. Unaligned addresses + may cause undefined results. For those parameters defined as reserved or some fields + defined as reserved must be zero filled or the invalid argument return value may be + returned or undefined result may occur during the execution of the procedure. + This function is only available on IPF. + + @param Index The PAL procedure Index number. + @param Arg2 The 2nd parameter for PAL procedure calls. + @param Arg3 The 3rd parameter for PAL procedure calls. + @param Arg4 The 4th parameter for PAL procedure calls. + + @return Structure returned from the PAL Call procedure, including the status and return value. + +**/ +PAL_CALL_RETURN +EFIAPI +PalCall ( + IN UINT64 Index, + IN UINT64 Arg2, + IN UINT64 Arg3, + IN UINT64 Arg4 + ) +{ + // + // mPalProcEntry is initialized in library constructor as PAL entry. + // + return AsmPalCall ( + mPalProcEntry, + Index, + Arg2, + Arg3, + Arg4 + ); + +} + +/** + The constructor function of UEFI Pal Lib. + + The constructor function looks up the SAL System Table in the EFI System Configuration + Table. Once the SAL System Table is found, the PAL Entry Point in the SAL System Table + will be derived and stored into a global variable for library usage. + It will ASSERT() if the SAL System Table cannot be found or the data in the SAL System + Table is not the valid data. + + @param ImageHandle The firmware allocated handle for the EFI image. + @param SystemTable A pointer to the EFI System Table. + + @retval EFI_SUCCESS The constructor always returns EFI_SUCCESS. + +**/ +EFI_STATUS +EFIAPI +UefiPalLibConstructor ( + IN EFI_HANDLE ImageHandle, + IN EFI_SYSTEM_TABLE *SystemTable + ) +{ + EFI_STATUS Status; + SAL_ST_ENTRY_POINT_DESCRIPTOR *SalStEntryDes; + SAL_SYSTEM_TABLE_HEADER *SalSystemTable; + + Status = EfiGetSystemConfigurationTable ( + &gEfiSalSystemTableGuid, + (VOID **) &SalSystemTable + ); + ASSERT_EFI_ERROR (Status); + ASSERT (SalSystemTable != NULL); + + // + // Check the first entry of SAL System Table, + // because the SAL entry is in ascending order with the entry type, + // the type 0 entry should be the first if exist. + // + SalStEntryDes = (SAL_ST_ENTRY_POINT_DESCRIPTOR *)(SalSystemTable + 1); + + // + // Assure the SAL ENTRY Type is 0 + // + ASSERT (SalStEntryDes->Type == EFI_SAL_ST_ENTRY_POINT); + + mPalProcEntry = SalStEntryDes->PalProcEntry; + // + // Make sure the PalCallAddress has the valid value + // + ASSERT (mPalProcEntry != 0); + + return EFI_SUCCESS; +} |