/******************************************************************************
*
* Module Name: utcksum - Support generating table checksums
*
*****************************************************************************/
/*
* Copyright (C) 2000 - 2022, Intel Corp.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions, and the following disclaimer,
* without modification.
* 2. Redistributions in binary form must reproduce at minimum a disclaimer
* substantially similar to the "NO WARRANTY" disclaimer below
* ("Disclaimer") and any redistribution must be conditioned upon
* including a substantially similar Disclaimer requirement for further
* binary redistribution.
* 3. Neither the names of the above-listed copyright holders nor the names
* of any contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* NO WARRANTY
* 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 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGES.
*/
#include "acpi.h"
#include "accommon.h"
#include "acdisasm.h"
#include "acutils.h"
/* This module used for application-level code only */
#define _COMPONENT ACPI_CA_DISASSEMBLER
ACPI_MODULE_NAME ("utcksum")
/*******************************************************************************
*
* FUNCTION: AcpiUtVerifyChecksum
*
* PARAMETERS: Table - ACPI table to verify
* Length - Length of entire table
*
* RETURN: Status
*
* DESCRIPTION: Verifies that the table checksums to zero. Optionally returns
* exception on bad checksum.
* Note: We don't have to check for a CDAT here, since CDAT is
* not in the RSDT/XSDT, and the CDAT table is never installed
* via ACPICA.
*
******************************************************************************/
ACPI_STATUS
AcpiUtVerifyChecksum (
ACPI_TABLE_HEADER *Table,
UINT32 Length)
{
UINT8 Checksum;
/*
* FACS/S3PT:
* They are the odd tables, have no standard ACPI header and no checksum
*/
if (ACPI_COMPARE_NAMESEG (Table->Signature, ACPI_SIG_S3PT) ||
ACPI_COMPARE_NAMESEG (Table->Signature, ACPI_SIG_FACS))
{
return (AE_OK);
}
/* Compute the checksum on the table */
Length = Table->Length;
Checksum = AcpiUtGenerateChecksum (ACPI_CAST_PTR (UINT8, Table), Length, Table->Checksum);
/* Computed checksum matches table? */
if (Checksum != Table->Checksum)
{
ACPI_BIOS_WARNING ((AE_INFO,
"Incorrect checksum in table [%4.4s] - 0x%2.2X, "
"should be 0x%2.2X",
Table->Signature, Table->Checksum,
Table->Checksum - Checksum));
#if (ACPI_CHECKSUM_ABORT)
return (AE_BAD_CHECKSUM);
#endif
}
return (AE_OK);
}
/*******************************************************************************
*
* FUNCTION: AcpiUtVerifyCdatChecksum
*
* PARAMETERS: Table - CDAT ACPI table to verify
* Length - Length of entire table
*
* RETURN: Status
*
* DESCRIPTION: Verifies that the CDAT table checksums to zero. Optionally
* returns an exception on bad checksum.
*
******************************************************************************/
ACPI_STATUS
AcpiUtVerifyCdatChecksum (
ACPI_TABLE_CDAT *CdatTable,
UINT32 Length)
{
UINT8 Checksum;
/* Compute the checksum on the table */
Checksum = AcpiUtGenerateChecksum (ACPI_CAST_PTR (UINT8, CdatTable),
CdatTable->Length, CdatTable->Checksum);
/* Computed checksum matches table? */
if (Checksum != CdatTable->Checksum)
{
ACPI_BIOS_WARNING ((AE_INFO,
"Incorrect checksum in table [%4.4s] - 0x%2.2X, "
"should be 0x%2.2X",
AcpiGbl_CDAT, CdatTable->Checksum, Checksum));
#if (ACPI_CHECKSUM_ABORT)
return (AE_BAD_CHECKSUM);
#endif
}
CdatTable->Checksum = Checksum;
return (AE_OK);
}
/*******************************************************************************
*
* FUNCTION: AcpiUtGenerateChecksum
*
* PARAMETERS: Table - Pointer to table to be checksummed
* Length - Length of the table
* OriginalChecksum - Value of the checksum field
*
* RETURN: 8 bit checksum of buffer
*
* DESCRIPTION: Computes an 8 bit checksum of the table.
*
******************************************************************************/
UINT8
AcpiUtGenerateChecksum (
void *Table,
UINT32 Length,
UINT8 OriginalChecksum)
{
UINT8 Checksum;
/* Sum the entire table as-is */
Checksum = AcpiUtChecksum ((UINT8 *) Table, Length);
/* Subtract off the existing checksum value in the table */
Checksum = (UINT8) (Checksum - OriginalChecksum);
/* Compute and return the final checksum */
Checksum = (UINT8) (0 - Checksum);
return (Checksum);
}
/*******************************************************************************
*
* FUNCTION: AcpiUtChecksum
*
* PARAMETERS: Buffer - Pointer to memory region to be checked
* Length - Length of this memory region
*
* RETURN: Checksum (UINT8)
*
* DESCRIPTION: Calculates circular checksum of memory region.
*
******************************************************************************/
UINT8
AcpiUtChecksum (
UINT8 *Buffer,
UINT32 Length)
{
UINT8 Sum = 0;
UINT8 *End = Buffer + Length;
while (Buffer < End)
{
Sum = (UINT8) (Sum + *(Buffer++));
}
return (Sum);
}