FreeBSD/Linux Kernel Cross Reference
sys/contrib/dev/acpica/components/executer/exconvrt.c

     /******************************************************************************
      *
      * Module Name: exconvrt - Object conversion routines
      *
      *****************************************************************************/
     
     /******************************************************************************
      *
      * 1. Copyright Notice
     *
     * Some or all of this work - Copyright (c) 1999 - 2022, Intel Corp.
     * All rights reserved.
     *
     * 2. License
     *
     * 2.1. This is your license from Intel Corp. under its intellectual property
     * rights. You may have additional license terms from the party that provided
     * you this software, covering your right to use that party's intellectual
     * property rights.
     *
     * 2.2. Intel grants, free of charge, to any person ("Licensee") obtaining a
     * copy of the source code appearing in this file ("Covered Code") an
     * irrevocable, perpetual, worldwide license under Intel's copyrights in the
     * base code distributed originally by Intel ("Original Intel Code") to copy,
     * make derivatives, distribute, use and display any portion of the Covered
     * Code in any form, with the right to sublicense such rights; and
     *
     * 2.3. Intel grants Licensee a non-exclusive and non-transferable patent
     * license (with the right to sublicense), under only those claims of Intel
     * patents that are infringed by the Original Intel Code, to make, use, sell,
     * offer to sell, and import the Covered Code and derivative works thereof
     * solely to the minimum extent necessary to exercise the above copyright
     * license, and in no event shall the patent license extend to any additions
     * to or modifications of the Original Intel Code. No other license or right
     * is granted directly or by implication, estoppel or otherwise;
     *
     * The above copyright and patent license is granted only if the following
     * conditions are met:
     *
     * 3. Conditions
     *
     * 3.1. Redistribution of Source with Rights to Further Distribute Source.
     * Redistribution of source code of any substantial portion of the Covered
     * Code or modification with rights to further distribute source must include
     * the above Copyright Notice, the above License, this list of Conditions,
     * and the following Disclaimer and Export Compliance provision. In addition,
     * Licensee must cause all Covered Code to which Licensee contributes to
     * contain a file documenting the changes Licensee made to create that Covered
     * Code and the date of any change. Licensee must include in that file the
     * documentation of any changes made by any predecessor Licensee. Licensee
     * must include a prominent statement that the modification is derived,
     * directly or indirectly, from Original Intel Code.
     *
     * 3.2. Redistribution of Source with no Rights to Further Distribute Source.
     * Redistribution of source code of any substantial portion of the Covered
     * Code or modification without rights to further distribute source must
     * include the following Disclaimer and Export Compliance provision in the
     * documentation and/or other materials provided with distribution. In
     * addition, Licensee may not authorize further sublicense of source of any
     * portion of the Covered Code, and must include terms to the effect that the
     * license from Licensee to its licensee is limited to the intellectual
     * property embodied in the software Licensee provides to its licensee, and
     * not to intellectual property embodied in modifications its licensee may
     * make.
     *
     * 3.3. Redistribution of Executable. Redistribution in executable form of any
     * substantial portion of the Covered Code or modification must reproduce the
     * above Copyright Notice, and the following Disclaimer and Export Compliance
     * provision in the documentation and/or other materials provided with the
     * distribution.
     *
     * 3.4. Intel retains all right, title, and interest in and to the Original
     * Intel Code.
     *
     * 3.5. Neither the name Intel nor any other trademark owned or controlled by
     * Intel shall be used in advertising or otherwise to promote the sale, use or
     * other dealings in products derived from or relating to the Covered Code
     * without prior written authorization from Intel.
     *
     * 4. Disclaimer and Export Compliance
     *
     * 4.1. INTEL MAKES NO WARRANTY OF ANY KIND REGARDING ANY SOFTWARE PROVIDED
     * HERE. ANY SOFTWARE ORIGINATING FROM INTEL OR DERIVED FROM INTEL SOFTWARE
     * IS PROVIDED "AS IS," AND INTEL WILL NOT PROVIDE ANY SUPPORT, ASSISTANCE,
     * INSTALLATION, TRAINING OR OTHER SERVICES. INTEL WILL NOT PROVIDE ANY
     * UPDATES, ENHANCEMENTS OR EXTENSIONS. INTEL SPECIFICALLY DISCLAIMS ANY
     * IMPLIED WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT AND FITNESS FOR A
     * PARTICULAR PURPOSE.
     *
     * 4.2. IN NO EVENT SHALL INTEL HAVE ANY LIABILITY TO LICENSEE, ITS LICENSEES
     * OR ANY OTHER THIRD PARTY, FOR ANY LOST PROFITS, LOST DATA, LOSS OF USE OR
     * COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY INDIRECT,
     * SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, UNDER ANY
     * CAUSE OF ACTION OR THEORY OF LIABILITY, AND IRRESPECTIVE OF WHETHER INTEL
     * HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES. THESE LIMITATIONS
     * SHALL APPLY NOTWITHSTANDING THE FAILURE OF THE ESSENTIAL PURPOSE OF ANY
     * LIMITED REMEDY.
     *
     * 4.3. Licensee shall not export, either directly or indirectly, any of this
    * software or system incorporating such software without first obtaining any
    * required license or other approval from the U. S. Department of Commerce or
    * any other agency or department of the United States Government. In the
    * event Licensee exports any such software from the United States or
    * re-exports any such software from a foreign destination, Licensee shall
    * ensure that the distribution and export/re-export of the software is in
    * compliance with all laws, regulations, orders, or other restrictions of the
    * U.S. Export Administration Regulations. Licensee agrees that neither it nor
    * any of its subsidiaries will export/re-export any technical data, process,
    * software, or service, directly or indirectly, to any country for which the
    * United States government or any agency thereof requires an export license,
    * other governmental approval, or letter of assurance, without first obtaining
    * such license, approval or letter.
    *
    *****************************************************************************
    *
    * Alternatively, you may choose to be licensed under the terms of the
    * following license:
    *
    * 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.
    *
    * 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
    * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    * 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 DAMAGE.
    *
    * Alternatively, you may choose to be licensed under the terms of the
    * GNU General Public License ("GPL") version 2 as published by the Free
    * Software Foundation.
    *
    *****************************************************************************/
   
   #include <contrib/dev/acpica/include/acpi.h>
   #include <contrib/dev/acpica/include/accommon.h>
   #include <contrib/dev/acpica/include/acinterp.h>
   #include <contrib/dev/acpica/include/amlcode.h>
   
   
   #define _COMPONENT          ACPI_EXECUTER
           ACPI_MODULE_NAME    ("exconvrt")
   
   /* Local prototypes */
   
   static UINT32
   AcpiExConvertToAscii (
       UINT64                  Integer,
       UINT16                  Base,
       UINT8                   *String,
       UINT8                   MaxLength);
   
   
   /*******************************************************************************
    *
    * FUNCTION:    AcpiExConvertToInteger
    *
    * PARAMETERS:  ObjDesc             - Object to be converted. Must be an
    *                                    Integer, Buffer, or String
    *              ResultDesc          - Where the new Integer object is returned
    *              ImplicitConversion  - Used for string conversion
    *
    * RETURN:      Status
    *
    * DESCRIPTION: Convert an ACPI Object to an integer.
    *
    ******************************************************************************/
   
   ACPI_STATUS
   AcpiExConvertToInteger (
       ACPI_OPERAND_OBJECT     *ObjDesc,
       ACPI_OPERAND_OBJECT     **ResultDesc,
       UINT32                  ImplicitConversion)
   {
       ACPI_OPERAND_OBJECT     *ReturnDesc;
       UINT8                   *Pointer;
       UINT64                  Result;
       UINT32                  i;
       UINT32                  Count;
   
   
       ACPI_FUNCTION_TRACE_PTR (ExConvertToInteger, ObjDesc);
   
   
       switch (ObjDesc->Common.Type)
       {
       case ACPI_TYPE_INTEGER:
   
           /* No conversion necessary */
   
           *ResultDesc = ObjDesc;
           return_ACPI_STATUS (AE_OK);
   
       case ACPI_TYPE_BUFFER:
       case ACPI_TYPE_STRING:
   
           /* Note: Takes advantage of common buffer/string fields */
   
           Pointer = ObjDesc->Buffer.Pointer;
           Count   = ObjDesc->Buffer.Length;
           break;
   
       default:
   
           return_ACPI_STATUS (AE_TYPE);
       }
   
       /*
        * Convert the buffer/string to an integer. Note that both buffers and
        * strings are treated as raw data - we don't convert ascii to hex for
        * strings.
        *
        * There are two terminating conditions for the loop:
        * 1) The size of an integer has been reached, or
        * 2) The end of the buffer or string has been reached
        */
       Result = 0;
   
       /* String conversion is different than Buffer conversion */
   
       switch (ObjDesc->Common.Type)
       {
       case ACPI_TYPE_STRING:
           /*
            * Convert string to an integer - for most cases, the string must be
            * hexadecimal as per the ACPI specification. The only exception (as
            * of ACPI 3.0) is that the ToInteger() operator allows both decimal
            * and hexadecimal strings (hex prefixed with "0x").
            *
            * Explicit conversion is used only by ToInteger.
            * All other string-to-integer conversions are implicit conversions.
            */
           if (ImplicitConversion)
           {
               Result = AcpiUtImplicitStrtoul64 (ACPI_CAST_PTR (char, Pointer));
           }
           else
           {
               Result = AcpiUtExplicitStrtoul64 (ACPI_CAST_PTR (char, Pointer));
           }
           break;
   
       case ACPI_TYPE_BUFFER:
   
           /* Check for zero-length buffer */
   
           if (!Count)
           {
               return_ACPI_STATUS (AE_AML_BUFFER_LIMIT);
           }
   
           /* Transfer no more than an integer's worth of data */
   
           if (Count > AcpiGbl_IntegerByteWidth)
           {
               Count = AcpiGbl_IntegerByteWidth;
           }
   
           /*
            * Convert buffer to an integer - we simply grab enough raw data
            * from the buffer to fill an integer
            */
           for (i = 0; i < Count; i++)
           {
               /*
                * Get next byte and shift it into the Result.
                * Little endian is used, meaning that the first byte of the buffer
                * is the LSB of the integer
                */
               Result |= (((UINT64) Pointer[i]) << (i * 8));
           }
           break;
   
       default:
   
           /* No other types can get here */
   
           break;
       }
   
       /* Create a new integer */
   
       ReturnDesc = AcpiUtCreateIntegerObject (Result);
       if (!ReturnDesc)
       {
           return_ACPI_STATUS (AE_NO_MEMORY);
       }
   
       ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, "Converted value: %8.8X%8.8X\n",
           ACPI_FORMAT_UINT64 (Result)));
   
       /* Save the Result */
   
       (void) AcpiExTruncateFor32bitTable (ReturnDesc);
       *ResultDesc = ReturnDesc;
       return_ACPI_STATUS (AE_OK);
   }
   
   
   /*******************************************************************************
    *
    * FUNCTION:    AcpiExConvertToBuffer
    *
    * PARAMETERS:  ObjDesc         - Object to be converted. Must be an
    *                                Integer, Buffer, or String
    *              ResultDesc      - Where the new buffer object is returned
    *
    * RETURN:      Status
    *
    * DESCRIPTION: Convert an ACPI Object to a Buffer
    *
    ******************************************************************************/
   
   ACPI_STATUS
   AcpiExConvertToBuffer (
       ACPI_OPERAND_OBJECT     *ObjDesc,
       ACPI_OPERAND_OBJECT     **ResultDesc)
   {
       ACPI_OPERAND_OBJECT     *ReturnDesc;
       UINT8                   *NewBuf;
   
   
       ACPI_FUNCTION_TRACE_PTR (ExConvertToBuffer, ObjDesc);
   
   
       switch (ObjDesc->Common.Type)
       {
       case ACPI_TYPE_BUFFER:
   
           /* No conversion necessary */
   
           *ResultDesc = ObjDesc;
           return_ACPI_STATUS (AE_OK);
   
   
       case ACPI_TYPE_INTEGER:
           /*
            * Create a new Buffer object.
            * Need enough space for one integer
            */
           ReturnDesc = AcpiUtCreateBufferObject (AcpiGbl_IntegerByteWidth);
           if (!ReturnDesc)
           {
               return_ACPI_STATUS (AE_NO_MEMORY);
           }
   
           /* Copy the integer to the buffer, LSB first */
   
           NewBuf = ReturnDesc->Buffer.Pointer;
           memcpy (NewBuf, &ObjDesc->Integer.Value, AcpiGbl_IntegerByteWidth);
           break;
   
       case ACPI_TYPE_STRING:
           /*
            * Create a new Buffer object
            * Size will be the string length
            *
            * NOTE: Add one to the string length to include the null terminator.
            * The ACPI spec is unclear on this subject, but there is existing
            * ASL/AML code that depends on the null being transferred to the new
            * buffer.
            */
           ReturnDesc = AcpiUtCreateBufferObject ((ACPI_SIZE)
               ObjDesc->String.Length + 1);
           if (!ReturnDesc)
           {
               return_ACPI_STATUS (AE_NO_MEMORY);
           }
   
           /* Copy the string to the buffer */
   
           NewBuf = ReturnDesc->Buffer.Pointer;
           strncpy ((char *) NewBuf, (char *) ObjDesc->String.Pointer,
               ObjDesc->String.Length);
           break;
   
       default:
   
           return_ACPI_STATUS (AE_TYPE);
       }
   
       /* Mark buffer initialized */
   
       ReturnDesc->Common.Flags |= AOPOBJ_DATA_VALID;
       *ResultDesc = ReturnDesc;
       return_ACPI_STATUS (AE_OK);
   }
   
   
   /*******************************************************************************
    *
    * FUNCTION:    AcpiExConvertToAscii
    *
    * PARAMETERS:  Integer         - Value to be converted
    *              Base            - ACPI_STRING_DECIMAL or ACPI_STRING_HEX
    *              String          - Where the string is returned
    *              DataWidth       - Size of data item to be converted, in bytes
    *
    * RETURN:      Actual string length
    *
    * DESCRIPTION: Convert an ACPI Integer to a hex or decimal string
    *
    ******************************************************************************/
   
   static UINT32
   AcpiExConvertToAscii (
       UINT64                  Integer,
       UINT16                  Base,
       UINT8                   *String,
       UINT8                   DataWidth)
   {
       UINT64                  Digit;
       UINT32                  i;
       UINT32                  j;
       UINT32                  k = 0;
       UINT32                  HexLength;
       UINT32                  DecimalLength;
       UINT32                  Remainder;
       BOOLEAN                 SupressZeros;
   
   
       ACPI_FUNCTION_ENTRY ();
   
   
       switch (Base)
       {
       case 10:
   
           /* Setup max length for the decimal number */
   
           switch (DataWidth)
           {
           case 1:
   
               DecimalLength = ACPI_MAX8_DECIMAL_DIGITS;
               break;
   
           case 4:
   
               DecimalLength = ACPI_MAX32_DECIMAL_DIGITS;
               break;
   
           case 8:
           default:
   
               DecimalLength = ACPI_MAX64_DECIMAL_DIGITS;
               break;
           }
   
           SupressZeros = TRUE;     /* No leading zeros */
           Remainder = 0;
   
           for (i = DecimalLength; i > 0; i--)
           {
               /* Divide by nth factor of 10 */
   
               Digit = Integer;
               for (j = 0; j < i; j++)
               {
                   (void) AcpiUtShortDivide (Digit, 10, &Digit, &Remainder);
               }
   
               /* Handle leading zeros */
   
               if (Remainder != 0)
               {
                   SupressZeros = FALSE;
               }
   
               if (!SupressZeros)
               {
                   String[k] = (UINT8) (ACPI_ASCII_ZERO + Remainder);
                   k++;
               }
           }
           break;
   
       case 16:
   
           /* HexLength: 2 ascii hex chars per data byte */
   
           HexLength = (DataWidth * 2);
           for (i = 0, j = (HexLength-1); i < HexLength; i++, j--)
           {
               /* Get one hex digit, most significant digits first */
   
               String[k] = (UINT8)
                   AcpiUtHexToAsciiChar (Integer, ACPI_MUL_4 (j));
               k++;
           }
           break;
   
       default:
           return (0);
       }
   
       /*
        * Since leading zeros are suppressed, we must check for the case where
        * the integer equals 0
        *
        * Finally, null terminate the string and return the length
        */
       if (!k)
       {
           String [0] = ACPI_ASCII_ZERO;
           k = 1;
       }
   
       String [k] = 0;
       return ((UINT32) k);
   }
   
   
   /*******************************************************************************
    *
    * FUNCTION:    AcpiExConvertToString
    *
    * PARAMETERS:  ObjDesc         - Object to be converted. Must be an
    *                                Integer, Buffer, or String
    *              ResultDesc      - Where the string object is returned
    *              Type            - String flags (base and conversion type)
    *
    * RETURN:      Status
    *
    * DESCRIPTION: Convert an ACPI Object to a string. Supports both implicit
    *              and explicit conversions and related rules.
    *
    ******************************************************************************/
   
   ACPI_STATUS
   AcpiExConvertToString (
       ACPI_OPERAND_OBJECT     *ObjDesc,
       ACPI_OPERAND_OBJECT     **ResultDesc,
       UINT32                  Type)
   {
       ACPI_OPERAND_OBJECT     *ReturnDesc;
       UINT8                   *NewBuf;
       UINT32                  i;
       UINT32                  StringLength = 0;
       UINT16                  Base = 16;
       UINT8                   Separator = ',';
   
   
       ACPI_FUNCTION_TRACE_PTR (ExConvertToString, ObjDesc);
   
   
       switch (ObjDesc->Common.Type)
       {
       case ACPI_TYPE_STRING:
   
           /* No conversion necessary */
   
           *ResultDesc = ObjDesc;
           return_ACPI_STATUS (AE_OK);
   
       case ACPI_TYPE_INTEGER:
   
           switch (Type)
           {
           case ACPI_EXPLICIT_CONVERT_DECIMAL:
               /*
                * From ToDecimalString, integer source.
                *
                * Make room for the maximum decimal number size
                */
               StringLength = ACPI_MAX_DECIMAL_DIGITS;
               Base = 10;
               break;
   
           default:
   
               /* Two hex string characters for each integer byte */
   
               StringLength = ACPI_MUL_2 (AcpiGbl_IntegerByteWidth);
               break;
           }
   
           /*
            * Create a new String
            * Need enough space for one ASCII integer (plus null terminator)
            */
           ReturnDesc = AcpiUtCreateStringObject ((ACPI_SIZE) StringLength);
           if (!ReturnDesc)
           {
               return_ACPI_STATUS (AE_NO_MEMORY);
           }
   
           NewBuf = ReturnDesc->Buffer.Pointer;
   
           /* Convert integer to string */
   
           StringLength = AcpiExConvertToAscii (
               ObjDesc->Integer.Value, Base, NewBuf, AcpiGbl_IntegerByteWidth);
   
           /* Null terminate at the correct place */
   
           ReturnDesc->String.Length = StringLength;
           NewBuf [StringLength] = 0;
           break;
   
       case ACPI_TYPE_BUFFER:
   
           /* Setup string length, base, and separator */
   
           switch (Type)
           {
           case ACPI_EXPLICIT_CONVERT_DECIMAL: /* Used by ToDecimalString */
               /*
                * Explicit conversion from the ToDecimalString ASL operator.
                *
                * From ACPI: "If the input is a buffer, it is converted to a
                * a string of decimal values separated by commas."
                */
               Base = 10;
   
               /*
                * Calculate the final string length. Individual string values
                * are variable length (include separator for each)
                */
               for (i = 0; i < ObjDesc->Buffer.Length; i++)
               {
                   if (ObjDesc->Buffer.Pointer[i] >= 100)
                   {
                       StringLength += 4;
                   }
                   else if (ObjDesc->Buffer.Pointer[i] >= 10)
                   {
                       StringLength += 3;
                   }
                   else
                   {
                       StringLength += 2;
                   }
               }
               break;
   
           case ACPI_IMPLICIT_CONVERT_HEX:
               /*
                * Implicit buffer-to-string conversion
                *
                * From the ACPI spec:
                * "The entire contents of the buffer are converted to a string of
                * two-character hexadecimal numbers, each separated by a space."
                *
                * Each hex number is prefixed with 0x (11/2018)
                */
               Separator = ' ';
               StringLength = (ObjDesc->Buffer.Length * 5);
               break;
   
           case ACPI_EXPLICIT_CONVERT_HEX:
               /*
                * Explicit conversion from the ToHexString ASL operator.
                *
                * From ACPI: "If Data is a buffer, it is converted to a string of
                * hexadecimal values separated by commas."
                *
                * Each hex number is prefixed with 0x (11/2018)
                */
               Separator = ',';
               StringLength = (ObjDesc->Buffer.Length * 5);
               break;
   
           default:
               return_ACPI_STATUS (AE_BAD_PARAMETER);
           }
   
           /*
            * Create a new string object and string buffer
            * (-1 because of extra separator included in StringLength from above)
            * Allow creation of zero-length strings from zero-length buffers.
            */
           if (StringLength)
           {
               StringLength--;
           }
   
           ReturnDesc = AcpiUtCreateStringObject ((ACPI_SIZE) StringLength);
           if (!ReturnDesc)
           {
               return_ACPI_STATUS (AE_NO_MEMORY);
           }
   
           NewBuf = ReturnDesc->Buffer.Pointer;
   
           /*
            * Convert buffer bytes to hex or decimal values
            * (separated by commas or spaces)
            */
           for (i = 0; i < ObjDesc->Buffer.Length; i++)
           {
               if (Base == 16)
               {
                   /* Emit 0x prefix for explicit/implicit hex conversion */
   
                   *NewBuf++ = '';
                   *NewBuf++ = 'x';
               }
   
               NewBuf += AcpiExConvertToAscii (
                   (UINT64) ObjDesc->Buffer.Pointer[i], Base, NewBuf, 1);
   
               /* Each digit is separated by either a comma or space */
   
               *NewBuf++ = Separator;
           }
   
           /*
            * Null terminate the string
            * (overwrites final comma/space from above)
            */
           if (ObjDesc->Buffer.Length)
           {
               NewBuf--;
           }
           *NewBuf = 0;
           break;
   
       default:
   
           return_ACPI_STATUS (AE_TYPE);
       }
   
       *ResultDesc = ReturnDesc;
       return_ACPI_STATUS (AE_OK);
   }
   
   
   /*******************************************************************************
    *
    * FUNCTION:    AcpiExConvertToTargetType
    *
    * PARAMETERS:  DestinationType     - Current type of the destination
    *              SourceDesc          - Source object to be converted.
    *              ResultDesc          - Where the converted object is returned
    *              WalkState           - Current method state
    *
    * RETURN:      Status
    *
    * DESCRIPTION: Implements "implicit conversion" rules for storing an object.
    *
    ******************************************************************************/
   
   ACPI_STATUS
   AcpiExConvertToTargetType (
       ACPI_OBJECT_TYPE        DestinationType,
       ACPI_OPERAND_OBJECT     *SourceDesc,
       ACPI_OPERAND_OBJECT     **ResultDesc,
       ACPI_WALK_STATE         *WalkState)
   {
       ACPI_STATUS             Status = AE_OK;
   
   
       ACPI_FUNCTION_TRACE (ExConvertToTargetType);
   
   
       /* Default behavior */
   
       *ResultDesc = SourceDesc;
   
       /*
        * If required by the target,
        * perform implicit conversion on the source before we store it.
        */
       switch (GET_CURRENT_ARG_TYPE (WalkState->OpInfo->RuntimeArgs))
       {
       case ARGI_SIMPLE_TARGET:
       case ARGI_FIXED_TARGET:
       case ARGI_INTEGER_REF:      /* Handles Increment, Decrement cases */
   
           switch (DestinationType)
           {
           case ACPI_TYPE_LOCAL_REGION_FIELD:
               /*
                * Named field can always handle conversions
                */
               break;
   
           default:
   
               /* No conversion allowed for these types */
   
               if (DestinationType != SourceDesc->Common.Type)
               {
                   ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
                       "Explicit operator, will store (%s) over existing type (%s)\n",
                       AcpiUtGetObjectTypeName (SourceDesc),
                       AcpiUtGetTypeName (DestinationType)));
                   Status = AE_TYPE;
               }
           }
           break;
   
       case ARGI_TARGETREF:
       case ARGI_STORE_TARGET:
   
           switch (DestinationType)
           {
           case ACPI_TYPE_INTEGER:
           case ACPI_TYPE_BUFFER_FIELD:
           case ACPI_TYPE_LOCAL_BANK_FIELD:
           case ACPI_TYPE_LOCAL_INDEX_FIELD:
               /*
                * These types require an Integer operand. We can convert
                * a Buffer or a String to an Integer if necessary.
                */
               Status = AcpiExConvertToInteger (SourceDesc, ResultDesc,
                   ACPI_IMPLICIT_CONVERSION);
               break;
   
           case ACPI_TYPE_STRING:
               /*
                * The operand must be a String. We can convert an
                * Integer or Buffer if necessary
                */
               Status = AcpiExConvertToString (SourceDesc, ResultDesc,
                   ACPI_IMPLICIT_CONVERT_HEX);
               break;
   
           case ACPI_TYPE_BUFFER:
               /*
                * The operand must be a Buffer. We can convert an
                * Integer or String if necessary
                */
               Status = AcpiExConvertToBuffer (SourceDesc, ResultDesc);
               break;
   
           default:
   
               ACPI_ERROR ((AE_INFO,
                   "Bad destination type during conversion: 0x%X",
                   DestinationType));
               Status = AE_AML_INTERNAL;
               break;
           }
           break;
   
       case ARGI_REFERENCE:
           /*
            * CreateXxxxField cases - we are storing the field object into the name
            */
           break;
   
       default:
   
           ACPI_ERROR ((AE_INFO,
               "Unknown Target type ID 0x%X AmlOpcode 0x%X DestType %s",
               GET_CURRENT_ARG_TYPE (WalkState->OpInfo->RuntimeArgs),
               WalkState->Opcode, AcpiUtGetTypeName (DestinationType)));
           Status = AE_AML_INTERNAL;
       }
   
       /*
        * Source-to-Target conversion semantics:
        *
        * If conversion to the target type cannot be performed, then simply
        * overwrite the target with the new object and type.
        */
       if (Status == AE_TYPE)
       {
           Status = AE_OK;
       }
   
       return_ACPI_STATUS (Status);
   }

Cache object: e5b6dc02910e45d9730332fa33bd3ebc