src/vendorcode/amd/cimx/sb700/ACPILIB.c

/*****************************************************************************
 *
 * Copyright (C) 2012 Advanced Micro Devices, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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#include	"Platform.h"

/*++

Routine Description:

  Locate ACPI table

Arguments:

  Signature - table signature

Returns:

  pointer to ACPI table

--*/
void* ACPI_LocateTable(
	UINT32 Signature
)
{
	UINT32	i;
	UINT32* RsdPtr = (UINT32*)0xe0000;
	UINT32* Rsdt = NULL;
	DESCRIPTION_HEADER* CurrentTable;
	do{
//		if (*RsdPtr == ' DSR' && *(RsdPtr+1) == ' RTP'){
		if ((*RsdPtr == Int32FromChar ('R', 'S', 'D', ' ')) && (*(RsdPtr+1) == Int32FromChar ('R', 'T', 'P', ' '))){
			Rsdt = (UINT32*)((RSDP*)RsdPtr)->RsdtAddress;
			break;
		}
		RsdPtr+=4;
	}while (RsdPtr <= (UINT32*)0xffff0);
	if(Rsdt != NULL && ACPI_GetTableChecksum(Rsdt)==0){
		for (i = 0;i < (((DESCRIPTION_HEADER*)Rsdt)->Length - sizeof(DESCRIPTION_HEADER))/4;i++){
			CurrentTable = (DESCRIPTION_HEADER*)*(UINT32*)((UINT8*)Rsdt + sizeof(DESCRIPTION_HEADER) + i*4);
			if (CurrentTable->Signature == Signature) return CurrentTable;
		}
	}
	return NULL;
}

/*++

Routine Description:

  Update table checksum

Arguments:

  TablePtr - table pointer

Returns:

  none

--*/
void  ACPI_SetTableChecksum(
	void* TablePtr
)
{
	UINT8 Checksum = 0;
	((DESCRIPTION_HEADER*)TablePtr)->Checksum = 0;
	Checksum = ACPI_GetTableChecksum(TablePtr);
	((DESCRIPTION_HEADER*)TablePtr)->Checksum = 0x100 - Checksum;
}

/*++

Routine Description:

  Get table checksum

Arguments:

  TablePtr - table pointer

Returns:

  none

--*/
UINT8  ACPI_GetTableChecksum(
	void* TablePtr
)
{
	return GetByteSum(TablePtr,((DESCRIPTION_HEADER*)TablePtr)->Length);
}