drivers/bus/acpi/acpica/executer/exconvrt.c

   1 /******************************************************************************
   2  *
   3  * Module Name: exconvrt - Object conversion routines
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2019, Intel Corp.
   9  * All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions, and the following disclaimer,
  16  *    without modification.
  17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  18  *    substantially similar to the "NO WARRANTY" disclaimer below
  19  *    ("Disclaimer") and any redistribution must be conditioned upon
  20  *    including a substantially similar Disclaimer requirement for further
  21  *    binary redistribution.
  22  * 3. Neither the names of the above-listed copyright holders nor the names
  23  *    of any contributors may be used to endorse or promote products derived
  24  *    from this software without specific prior written permission.
  25  *
  26  * Alternatively, this software may be distributed under the terms of the
  27  * GNU General Public License ("GPL") version 2 as published by the Free
  28  * Software Foundation.
  29  *
  30  * NO WARRANTY
  31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  41  * POSSIBILITY OF SUCH DAMAGES.
  42  */
  43
  44 #include "acpi.h"
  45 #include "accommon.h"
  46 #include "acinterp.h"
  47 #include "amlcode.h"
  48
  49
  50 #define _COMPONENT          ACPI_EXECUTER
  51         ACPI_MODULE_NAME    ("exconvrt")
  52
  53 /* Local prototypes */
  54
  55 static UINT32
  56 AcpiExConvertToAscii (
  57     UINT64                  Integer,
  58     UINT16                  Base,
  59     UINT8                   *String,
  60     UINT8                   MaxLength);
  61
  62
  63 /*******************************************************************************
  64  *
  65  * FUNCTION:    AcpiExConvertToInteger
  66  *
  67  * PARAMETERS:  ObjDesc             - Object to be converted. Must be an
  68  *                                    Integer, Buffer, or String
  69  *              ResultDesc          - Where the new Integer object is returned
  70  *              ImplicitConversion  - Used for string conversion
  71  *
  72  * RETURN:      Status
  73  *
  74  * DESCRIPTION: Convert an ACPI Object to an integer.
  75  *
  76  ******************************************************************************/
  77
  78 ACPI_STATUS
  79 AcpiExConvertToInteger (
  80     ACPI_OPERAND_OBJECT     *ObjDesc,
  81     ACPI_OPERAND_OBJECT     **ResultDesc,
  82     UINT32                  ImplicitConversion)
  83 {
  84     ACPI_OPERAND_OBJECT     *ReturnDesc;
  85     UINT8                   *Pointer;
  86     UINT64                  Result;
  87     UINT32                  i;
  88     UINT32                  Count;
  89
  90
  91     ACPI_FUNCTION_TRACE_PTR (ExConvertToInteger, ObjDesc);
  92
  93
  94     switch (ObjDesc->Common.Type)
  95     {
  96     case ACPI_TYPE_INTEGER:
  97
  98         /* No conversion necessary */
  99
 100         *ResultDesc = ObjDesc;
 101         return_ACPI_STATUS (AE_OK);
 102
 103     case ACPI_TYPE_BUFFER:
 104     case ACPI_TYPE_STRING:
 105
 106         /* Note: Takes advantage of common buffer/string fields */
 107
 108         Pointer = ObjDesc->Buffer.Pointer;
 109         Count   = ObjDesc->Buffer.Length;
 110         break;
 111
 112     default:
 113
 114         return_ACPI_STATUS (AE_TYPE);
 115     }
 116
 117     /*
 118      * Convert the buffer/string to an integer. Note that both buffers and
 119      * strings are treated as raw data - we don't convert ascii to hex for
 120      * strings.
 121      *
 122      * There are two terminating conditions for the loop:
 123      * 1) The size of an integer has been reached, or
 124      * 2) The end of the buffer or string has been reached
 125      */
 126     Result = 0;
 127
 128     /* String conversion is different than Buffer conversion */
 129
 130     switch (ObjDesc->Common.Type)
 131     {
 132     case ACPI_TYPE_STRING:
 133         /*
 134          * Convert string to an integer - for most cases, the string must be
 135          * hexadecimal as per the ACPI specification. The only exception (as
 136          * of ACPI 3.0) is that the ToInteger() operator allows both decimal
 137          * and hexadecimal strings (hex prefixed with "0x").
 138          *
 139          * Explicit conversion is used only by ToInteger.
 140          * All other string-to-integer conversions are implicit conversions.
 141          */
 142         if (ImplicitConversion)
 143         {
 144             Result = AcpiUtImplicitStrtoul64 (ACPI_CAST_PTR (char, Pointer));
 145         }
 146         else
 147         {
 148             Result = AcpiUtExplicitStrtoul64 (ACPI_CAST_PTR (char, Pointer));
 149         }
 150         break;
 151
 152     case ACPI_TYPE_BUFFER:
 153
 154         /* Check for zero-length buffer */
 155
 156         if (!Count)
 157         {
 158             return_ACPI_STATUS (AE_AML_BUFFER_LIMIT);
 159         }
 160
 161         /* Transfer no more than an integer's worth of data */
 162
 163         if (Count > AcpiGbl_IntegerByteWidth)
 164         {
 165             Count = AcpiGbl_IntegerByteWidth;
 166         }
 167
 168         /*
 169          * Convert buffer to an integer - we simply grab enough raw data
 170          * from the buffer to fill an integer
 171          */
 172         for (i = 0; i < Count; i++)
 173         {
 174             /*
 175              * Get next byte and shift it into the Result.
 176              * Little endian is used, meaning that the first byte of the buffer
 177              * is the LSB of the integer
 178              */
 179             Result |= (((UINT64) Pointer[i]) << (i * 8));
 180         }
 181         break;
 182
 183     default:
 184
 185         /* No other types can get here */
 186
 187         break;
 188     }
 189
 190     /* Create a new integer */
 191
 192     ReturnDesc = AcpiUtCreateIntegerObject (Result);
 193     if (!ReturnDesc)
 194     {
 195         return_ACPI_STATUS (AE_NO_MEMORY);
 196     }
 197
 198     ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, "Converted value: %8.8X%8.8X\n",
 199         ACPI_FORMAT_UINT64 (Result)));
 200
 201     /* Save the Result */
 202
 203     (void) AcpiExTruncateFor32bitTable (ReturnDesc);
 204     *ResultDesc = ReturnDesc;
 205     return_ACPI_STATUS (AE_OK);
 206 }
 207
 208
 209 /*******************************************************************************
 210  *
 211  * FUNCTION:    AcpiExConvertToBuffer
 212  *
 213  * PARAMETERS:  ObjDesc         - Object to be converted. Must be an
 214  *                                Integer, Buffer, or String
 215  *              ResultDesc      - Where the new buffer object is returned
 216  *
 217  * RETURN:      Status
 218  *
 219  * DESCRIPTION: Convert an ACPI Object to a Buffer
 220  *
 221  ******************************************************************************/
 222
 223 ACPI_STATUS
 224 AcpiExConvertToBuffer (
 225     ACPI_OPERAND_OBJECT     *ObjDesc,
 226     ACPI_OPERAND_OBJECT     **ResultDesc)
 227 {
 228     ACPI_OPERAND_OBJECT     *ReturnDesc;
 229     UINT8                   *NewBuf;
 230
 231
 232     ACPI_FUNCTION_TRACE_PTR (ExConvertToBuffer, ObjDesc);
 233
 234
 235     switch (ObjDesc->Common.Type)
 236     {
 237     case ACPI_TYPE_BUFFER:
 238
 239         /* No conversion necessary */
 240
 241         *ResultDesc = ObjDesc;
 242         return_ACPI_STATUS (AE_OK);
 243
 244
 245     case ACPI_TYPE_INTEGER:
 246         /*
 247          * Create a new Buffer object.
 248          * Need enough space for one integer
 249          */
 250         ReturnDesc = AcpiUtCreateBufferObject (AcpiGbl_IntegerByteWidth);
 251         if (!ReturnDesc)
 252         {
 253             return_ACPI_STATUS (AE_NO_MEMORY);
 254         }
 255
 256         /* Copy the integer to the buffer, LSB first */
 257
 258         NewBuf = ReturnDesc->Buffer.Pointer;
 259         memcpy (NewBuf, &ObjDesc->Integer.Value, AcpiGbl_IntegerByteWidth);
 260         break;
 261
 262     case ACPI_TYPE_STRING:
 263         /*
 264          * Create a new Buffer object
 265          * Size will be the string length
 266          *
 267          * NOTE: Add one to the string length to include the null terminator.
 268          * The ACPI spec is unclear on this subject, but there is existing
 269          * ASL/AML code that depends on the null being transferred to the new
 270          * buffer.
 271          */
 272         ReturnDesc = AcpiUtCreateBufferObject ((ACPI_SIZE)
 273             ObjDesc->String.Length + 1);
 274         if (!ReturnDesc)
 275         {
 276             return_ACPI_STATUS (AE_NO_MEMORY);
 277         }
 278
 279         /* Copy the string to the buffer */
 280
 281         NewBuf = ReturnDesc->Buffer.Pointer;
 282         strncpy ((char *) NewBuf, (char *) ObjDesc->String.Pointer,
 283             ObjDesc->String.Length);
 284         break;
 285
 286     default:
 287
 288         return_ACPI_STATUS (AE_TYPE);
 289     }
 290
 291     /* Mark buffer initialized */
 292
 293     ReturnDesc->Common.Flags |= AOPOBJ_DATA_VALID;
 294     *ResultDesc = ReturnDesc;
 295     return_ACPI_STATUS (AE_OK);
 296 }
 297
 298
 299 /*******************************************************************************
 300  *
 301  * FUNCTION:    AcpiExConvertToAscii
 302  *
 303  * PARAMETERS:  Integer         - Value to be converted
 304  *              Base            - ACPI_STRING_DECIMAL or ACPI_STRING_HEX
 305  *              String          - Where the string is returned
 306  *              DataWidth       - Size of data item to be converted, in bytes
 307  *
 308  * RETURN:      Actual string length
 309  *
 310  * DESCRIPTION: Convert an ACPI Integer to a hex or decimal string
 311  *
 312  ******************************************************************************/
 313
 314 static UINT32
 315 AcpiExConvertToAscii (
 316     UINT64                  Integer,
 317     UINT16                  Base,
 318     UINT8                   *String,
 319     UINT8                   DataWidth)
 320 {
 321     UINT64                  Digit;
 322     UINT32                  i;
 323     UINT32                  j;
 324     UINT32                  k = 0;
 325     UINT32                  HexLength;
 326     UINT32                  DecimalLength;
 327     UINT32                  Remainder;
 328     BOOLEAN                 SupressZeros;
 329
 330
 331     ACPI_FUNCTION_ENTRY ();
 332
 333
 334     switch (Base)
 335     {
 336     case 10:
 337
 338         /* Setup max length for the decimal number */
 339
 340         switch (DataWidth)
 341         {
 342         case 1:
 343
 344             DecimalLength = ACPI_MAX8_DECIMAL_DIGITS;
 345             break;
 346
 347         case 4:
 348
 349             DecimalLength = ACPI_MAX32_DECIMAL_DIGITS;
 350             break;
 351
 352         case 8:
 353         default:
 354
 355             DecimalLength = ACPI_MAX64_DECIMAL_DIGITS;
 356             break;
 357         }
 358
 359         SupressZeros = TRUE;     /* No leading zeros */
 360         Remainder = 0;
 361
 362         for (i = DecimalLength; i > 0; i--)
 363         {
 364             /* Divide by nth factor of 10 */
 365
 366             Digit = Integer;
 367             for (j = 0; j < i; j++)
 368             {
 369                 (void) AcpiUtShortDivide (Digit, 10, &Digit, &Remainder);
 370             }
 371
 372             /* Handle leading zeros */
 373
 374             if (Remainder != 0)
 375             {
 376                 SupressZeros = FALSE;
 377             }
 378
 379             if (!SupressZeros)
 380             {
 381                 String[k] = (UINT8) (ACPI_ASCII_ZERO + Remainder);
 382                 k++;
 383             }
 384         }
 385         break;
 386
 387     case 16:
 388
 389         /* HexLength: 2 ascii hex chars per data byte */
 390
 391         HexLength = (DataWidth * 2);
 392         for (i = 0, j = (HexLength-1); i < HexLength; i++, j--)
 393         {
 394             /* Get one hex digit, most significant digits first */
 395
 396             String[k] = (UINT8)
 397                 AcpiUtHexToAsciiChar (Integer, ACPI_MUL_4 (j));
 398             k++;
 399         }
 400         break;
 401
 402     default:
 403         return (0);
 404     }
 405
 406     /*
 407      * Since leading zeros are suppressed, we must check for the case where
 408      * the integer equals 0
 409      *
 410      * Finally, null terminate the string and return the length
 411      */
 412     if (!k)
 413     {
 414         String [0] = ACPI_ASCII_ZERO;
 415         k = 1;
 416     }
 417
 418     String [k] = 0;
 419     return ((UINT32) k);
 420 }
 421
 422
 423 /*******************************************************************************
 424  *
 425  * FUNCTION:    AcpiExConvertToString
 426  *
 427  * PARAMETERS:  ObjDesc         - Object to be converted. Must be an
 428  *                                Integer, Buffer, or String
 429  *              ResultDesc      - Where the string object is returned
 430  *              Type            - String flags (base and conversion type)
 431  *
 432  * RETURN:      Status
 433  *
 434  * DESCRIPTION: Convert an ACPI Object to a string. Supports both implicit
 435  *              and explicit conversions and related rules.
 436  *
 437  ******************************************************************************/
 438
 439 ACPI_STATUS
 440 AcpiExConvertToString (
 441     ACPI_OPERAND_OBJECT     *ObjDesc,
 442     ACPI_OPERAND_OBJECT     **ResultDesc,
 443     UINT32                  Type)
 444 {
 445     ACPI_OPERAND_OBJECT     *ReturnDesc;
 446     UINT8                   *NewBuf;
 447     UINT32                  i;
 448     UINT32                  StringLength = 0;
 449     UINT16                  Base = 16;
 450     UINT8                   Separator = ',';
 451
 452
 453     ACPI_FUNCTION_TRACE_PTR (ExConvertToString, ObjDesc);
 454
 455
 456     switch (ObjDesc->Common.Type)
 457     {
 458     case ACPI_TYPE_STRING:
 459
 460         /* No conversion necessary */
 461
 462         *ResultDesc = ObjDesc;
 463         return_ACPI_STATUS (AE_OK);
 464
 465     case ACPI_TYPE_INTEGER:
 466
 467         switch (Type)
 468         {
 469         case ACPI_EXPLICIT_CONVERT_DECIMAL:
 470             /*
 471              * From ToDecimalString, integer source.
 472              *
 473              * Make room for the maximum decimal number size
 474              */
 475             StringLength = ACPI_MAX_DECIMAL_DIGITS;
 476             Base = 10;
 477             break;
 478
 479         default:
 480
 481             /* Two hex string characters for each integer byte */
 482
 483             StringLength = ACPI_MUL_2 (AcpiGbl_IntegerByteWidth);
 484             break;
 485         }
 486
 487         /*
 488          * Create a new String
 489          * Need enough space for one ASCII integer (plus null terminator)
 490          */
 491         ReturnDesc = AcpiUtCreateStringObject ((ACPI_SIZE) StringLength);
 492         if (!ReturnDesc)
 493         {
 494             return_ACPI_STATUS (AE_NO_MEMORY);
 495         }
 496
 497         NewBuf = ReturnDesc->Buffer.Pointer;
 498
 499         /* Convert integer to string */
 500
 501         StringLength = AcpiExConvertToAscii (
 502             ObjDesc->Integer.Value, Base, NewBuf, AcpiGbl_IntegerByteWidth);
 503
 504         /* Null terminate at the correct place */
 505
 506         ReturnDesc->String.Length = StringLength;
 507         NewBuf [StringLength] = 0;
 508         break;
 509
 510     case ACPI_TYPE_BUFFER:
 511
 512         /* Setup string length, base, and separator */
 513
 514         switch (Type)
 515         {
 516         case ACPI_EXPLICIT_CONVERT_DECIMAL: /* Used by ToDecimalString */
 517             /*
 518              * Explicit conversion from the ToDecimalString ASL operator.
 519              *
 520              * From ACPI: "If the input is a buffer, it is converted to a
 521              * a string of decimal values separated by commas."
 522              */
 523             Base = 10;
 524
 525             /*
 526              * Calculate the final string length. Individual string values
 527              * are variable length (include separator for each)
 528              */
 529             for (i = 0; i < ObjDesc->Buffer.Length; i++)
 530             {
 531                 if (ObjDesc->Buffer.Pointer[i] >= 100)
 532                 {
 533                     StringLength += 4;
 534                 }
 535                 else if (ObjDesc->Buffer.Pointer[i] >= 10)
 536                 {
 537                     StringLength += 3;
 538                 }
 539                 else
 540                 {
 541                     StringLength += 2;
 542                 }
 543             }
 544             break;
 545
 546         case ACPI_IMPLICIT_CONVERT_HEX:
 547             /*
 548              * Implicit buffer-to-string conversion
 549              *
 550              * From the ACPI spec:
 551              * "The entire contents of the buffer are converted to a string of
 552              * two-character hexadecimal numbers, each separated by a space."
 553              *
 554              * Each hex number is prefixed with 0x (11/2018)
 555              */
 556             Separator = ' ';
 557             StringLength = (ObjDesc->Buffer.Length * 5);
 558             break;
 559
 560         case ACPI_EXPLICIT_CONVERT_HEX:
 561             /*
 562              * Explicit conversion from the ToHexString ASL operator.
 563              *
 564              * From ACPI: "If Data is a buffer, it is converted to a string of
 565              * hexadecimal values separated by commas."
 566              *
 567              * Each hex number is prefixed with 0x (11/2018)
 568              */
 569             Separator = ',';
 570             StringLength = (ObjDesc->Buffer.Length * 5);
 571             break;
 572
 573         default:
 574             return_ACPI_STATUS (AE_BAD_PARAMETER);
 575         }
 576
 577         /*
 578          * Create a new string object and string buffer
 579          * (-1 because of extra separator included in StringLength from above)
 580          * Allow creation of zero-length strings from zero-length buffers.
 581          */
 582         if (StringLength)
 583         {
 584             StringLength--;
 585         }
 586
 587         ReturnDesc = AcpiUtCreateStringObject ((ACPI_SIZE) StringLength);
 588         if (!ReturnDesc)
 589         {
 590             return_ACPI_STATUS (AE_NO_MEMORY);
 591         }
 592
 593         NewBuf = ReturnDesc->Buffer.Pointer;
 594
 595         /*
 596          * Convert buffer bytes to hex or decimal values
 597          * (separated by commas or spaces)
 598          */
 599         for (i = 0; i < ObjDesc->Buffer.Length; i++)
 600         {
 601             if (Base == 16)
 602             {
 603                 /* Emit 0x prefix for explict/implicit hex conversion */
 604
 605                 *NewBuf++ = '0';
 606                 *NewBuf++ = 'x';
 607             }
 608
 609             NewBuf += AcpiExConvertToAscii (
 610                 (UINT64) ObjDesc->Buffer.Pointer[i], Base, NewBuf, 1);
 611
 612             /* Each digit is separated by either a comma or space */
 613
 614             *NewBuf++ = Separator;
 615         }
 616
 617         /*
 618          * Null terminate the string
 619          * (overwrites final comma/space from above)
 620          */
 621         if (ObjDesc->Buffer.Length)
 622         {
 623             NewBuf--;
 624         }
 625         *NewBuf = 0;
 626         break;
 627
 628     default:
 629
 630         return_ACPI_STATUS (AE_TYPE);
 631     }
 632
 633     *ResultDesc = ReturnDesc;
 634     return_ACPI_STATUS (AE_OK);
 635 }
 636
 637
 638 /*******************************************************************************
 639  *
 640  * FUNCTION:    AcpiExConvertToTargetType
 641  *
 642  * PARAMETERS:  DestinationType     - Current type of the destination
 643  *              SourceDesc          - Source object to be converted.
 644  *              ResultDesc          - Where the converted object is returned
 645  *              WalkState           - Current method state
 646  *
 647  * RETURN:      Status
 648  *
 649  * DESCRIPTION: Implements "implicit conversion" rules for storing an object.
 650  *
 651  ******************************************************************************/
 652
 653 ACPI_STATUS
 654 AcpiExConvertToTargetType (
 655     ACPI_OBJECT_TYPE        DestinationType,
 656     ACPI_OPERAND_OBJECT     *SourceDesc,
 657     ACPI_OPERAND_OBJECT     **ResultDesc,
 658     ACPI_WALK_STATE         *WalkState)
 659 {
 660     ACPI_STATUS             Status = AE_OK;
 661
 662
 663     ACPI_FUNCTION_TRACE (ExConvertToTargetType);
 664
 665
 666     /* Default behavior */
 667
 668     *ResultDesc = SourceDesc;
 669
 670     /*
 671      * If required by the target,
 672      * perform implicit conversion on the source before we store it.
 673      */
 674     switch (GET_CURRENT_ARG_TYPE (WalkState->OpInfo->RuntimeArgs))
 675     {
 676     case ARGI_SIMPLE_TARGET:
 677     case ARGI_FIXED_TARGET:
 678     case ARGI_INTEGER_REF:      /* Handles Increment, Decrement cases */
 679
 680         switch (DestinationType)
 681         {
 682         case ACPI_TYPE_LOCAL_REGION_FIELD:
 683             /*
 684              * Named field can always handle conversions
 685              */
 686             break;
 687
 688         default:
 689
 690             /* No conversion allowed for these types */
 691
 692             if (DestinationType != SourceDesc->Common.Type)
 693             {
 694                 ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
 695                     "Explicit operator, will store (%s) over existing type (%s)\n",
 696                     AcpiUtGetObjectTypeName (SourceDesc),
 697                     AcpiUtGetTypeName (DestinationType)));
 698                 Status = AE_TYPE;
 699             }
 700         }
 701         break;
 702
 703     case ARGI_TARGETREF:
 704     case ARGI_STORE_TARGET:
 705
 706         switch (DestinationType)
 707         {
 708         case ACPI_TYPE_INTEGER:
 709         case ACPI_TYPE_BUFFER_FIELD:
 710         case ACPI_TYPE_LOCAL_BANK_FIELD:
 711         case ACPI_TYPE_LOCAL_INDEX_FIELD:
 712             /*
 713              * These types require an Integer operand. We can convert
 714              * a Buffer or a String to an Integer if necessary.
 715              */
 716             Status = AcpiExConvertToInteger (SourceDesc, ResultDesc,
 717                 ACPI_IMPLICIT_CONVERSION);
 718             break;
 719
 720         case ACPI_TYPE_STRING:
 721             /*
 722              * The operand must be a String. We can convert an
 723              * Integer or Buffer if necessary
 724              */
 725             Status = AcpiExConvertToString (SourceDesc, ResultDesc,
 726                 ACPI_IMPLICIT_CONVERT_HEX);
 727             break;
 728
 729         case ACPI_TYPE_BUFFER:
 730             /*
 731              * The operand must be a Buffer. We can convert an
 732              * Integer or String if necessary
 733              */
 734             Status = AcpiExConvertToBuffer (SourceDesc, ResultDesc);
 735             break;
 736
 737         default:
 738
 739             ACPI_ERROR ((AE_INFO,
 740                 "Bad destination type during conversion: 0x%X",
 741                 DestinationType));
 742             Status = AE_AML_INTERNAL;
 743             break;
 744         }
 745         break;
 746
 747     case ARGI_REFERENCE:
 748         /*
 749          * CreateXxxxField cases - we are storing the field object into the name
 750          */
 751         break;
 752
 753     default:
 754
 755         ACPI_ERROR ((AE_INFO,
 756             "Unknown Target type ID 0x%X AmlOpcode 0x%X DestType %s",
 757             GET_CURRENT_ARG_TYPE (WalkState->OpInfo->RuntimeArgs),
 758             WalkState->Opcode, AcpiUtGetTypeName (DestinationType)));
 759         Status = AE_AML_INTERNAL;
 760     }
 761
 762     /*
 763      * Source-to-Target conversion semantics:
 764      *
 765      * If conversion to the target type cannot be performed, then simply
 766      * overwrite the target with the new object and type.
 767      */
 768     if (Status == AE_TYPE)
 769     {
 770         Status = AE_OK;
 771     }
 772
 773     return_ACPI_STATUS (Status);
 774 }