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acfileio.c revision 1.1
      1  1.1  christos /******************************************************************************
      2  1.1  christos  *
      3  1.1  christos  * Module Name: acfileio - Get ACPI tables from file
      4  1.1  christos  *
      5  1.1  christos  *****************************************************************************/
      6  1.1  christos 
      7  1.1  christos /*
      8  1.1  christos  * Copyright (C) 2000 - 2016, Intel Corp.
      9  1.1  christos  * All rights reserved.
     10  1.1  christos  *
     11  1.1  christos  * Redistribution and use in source and binary forms, with or without
     12  1.1  christos  * modification, are permitted provided that the following conditions
     13  1.1  christos  * are met:
     14  1.1  christos  * 1. Redistributions of source code must retain the above copyright
     15  1.1  christos  *    notice, this list of conditions, and the following disclaimer,
     16  1.1  christos  *    without modification.
     17  1.1  christos  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
     18  1.1  christos  *    substantially similar to the "NO WARRANTY" disclaimer below
     19  1.1  christos  *    ("Disclaimer") and any redistribution must be conditioned upon
     20  1.1  christos  *    including a substantially similar Disclaimer requirement for further
     21  1.1  christos  *    binary redistribution.
     22  1.1  christos  * 3. Neither the names of the above-listed copyright holders nor the names
     23  1.1  christos  *    of any contributors may be used to endorse or promote products derived
     24  1.1  christos  *    from this software without specific prior written permission.
     25  1.1  christos  *
     26  1.1  christos  * Alternatively, this software may be distributed under the terms of the
     27  1.1  christos  * GNU General Public License ("GPL") version 2 as published by the Free
     28  1.1  christos  * Software Foundation.
     29  1.1  christos  *
     30  1.1  christos  * NO WARRANTY
     31  1.1  christos  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     32  1.1  christos  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     33  1.1  christos  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
     34  1.1  christos  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     35  1.1  christos  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     36  1.1  christos  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     37  1.1  christos  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     38  1.1  christos  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
     39  1.1  christos  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
     40  1.1  christos  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     41  1.1  christos  * POSSIBILITY OF SUCH DAMAGES.
     42  1.1  christos  */
     43  1.1  christos 
     44  1.1  christos #include "acpi.h"
     45  1.1  christos #include "accommon.h"
     46  1.1  christos #include "acapps.h"
     47  1.1  christos #include "actables.h"
     48  1.1  christos #include "acutils.h"
     49  1.1  christos #include <errno.h>
     50  1.1  christos 
     51  1.1  christos #define _COMPONENT          ACPI_UTILITIES
     52  1.1  christos         ACPI_MODULE_NAME    ("acfileio")
     53  1.1  christos 
     54  1.1  christos 
     55  1.1  christos /* Local prototypes */
     56  1.1  christos 
     57  1.1  christos static ACPI_STATUS
     58  1.1  christos AcGetOneTableFromFile (
     59  1.1  christos     char                    *Filename,
     60  1.1  christos     FILE                    *File,
     61  1.1  christos     UINT8                   GetOnlyAmlTables,
     62  1.1  christos     ACPI_TABLE_HEADER       **Table);
     63  1.1  christos 
     64  1.1  christos static ACPI_STATUS
     65  1.1  christos AcCheckTextModeCorruption (
     66  1.1  christos     ACPI_TABLE_HEADER       *Table);
     67  1.1  christos 
     68  1.1  christos 
     69  1.1  christos /*******************************************************************************
     70  1.1  christos  *
     71  1.1  christos  * FUNCTION:    AcGetAllTablesFromFile
     72  1.1  christos  *
     73  1.1  christos  * PARAMETERS:  Filename            - Table filename
     74  1.1  christos  *              GetOnlyAmlTables    - TRUE if the tables must be AML tables
     75  1.1  christos  *              ReturnListHead      - Where table list is returned
     76  1.1  christos  *
     77  1.1  christos  * RETURN:      Status
     78  1.1  christos  *
     79  1.1  christos  * DESCRIPTION: Get all ACPI tables from within a single file.
     80  1.1  christos  *
     81  1.1  christos  ******************************************************************************/
     82  1.1  christos 
     83  1.1  christos ACPI_STATUS
     84  1.1  christos AcGetAllTablesFromFile (
     85  1.1  christos     char                    *Filename,
     86  1.1  christos     UINT8                   GetOnlyAmlTables,
     87  1.1  christos     ACPI_NEW_TABLE_DESC     **ReturnListHead)
     88  1.1  christos {
     89  1.1  christos     ACPI_NEW_TABLE_DESC     *ListHead = NULL;
     90  1.1  christos     ACPI_NEW_TABLE_DESC     *ListTail = NULL;
     91  1.1  christos     ACPI_NEW_TABLE_DESC     *TableDesc;
     92  1.1  christos     FILE                    *File;
     93  1.1  christos     ACPI_TABLE_HEADER       *Table = NULL;
     94  1.1  christos     UINT32                  FileSize;
     95  1.1  christos     ACPI_STATUS             Status = AE_OK;
     96  1.1  christos 
     97  1.1  christos 
     98  1.1  christos     File = fopen (Filename, "rb");
     99  1.1  christos     if (!File)
    100  1.1  christos     {
    101  1.1  christos         perror ("Could not open input file");
    102  1.1  christos         if (errno == ENOENT)
    103  1.1  christos         {
    104  1.1  christos             return (AE_NOT_EXIST);
    105  1.1  christos         }
    106  1.1  christos 
    107  1.1  christos         return (AE_ERROR);
    108  1.1  christos     }
    109  1.1  christos 
    110  1.1  christos     /* Get the file size */
    111  1.1  christos 
    112  1.1  christos     FileSize = CmGetFileSize (File);
    113  1.1  christos     if (FileSize == ACPI_UINT32_MAX)
    114  1.1  christos     {
    115  1.1  christos         return (AE_ERROR);
    116  1.1  christos     }
    117  1.1  christos 
    118  1.1  christos     fprintf (stderr,
    119  1.1  christos         "Input file %s, Length 0x%X (%u) bytes\n",
    120  1.1  christos         Filename, FileSize, FileSize);
    121  1.1  christos 
    122  1.1  christos     /* We must have at least one ACPI table header */
    123  1.1  christos 
    124  1.1  christos     if (FileSize < sizeof (ACPI_TABLE_HEADER))
    125  1.1  christos     {
    126  1.1  christos         return (AE_BAD_HEADER);
    127  1.1  christos     }
    128  1.1  christos 
    129  1.1  christos     /* Check for an non-binary file */
    130  1.1  christos 
    131  1.1  christos     if (!AcIsFileBinary (File))
    132  1.1  christos     {
    133  1.1  christos         fprintf (stderr,
    134  1.1  christos             "    %s: File does not appear to contain a valid AML table\n",
    135  1.1  christos             Filename);
    136  1.1  christos         return (AE_TYPE);
    137  1.1  christos     }
    138  1.1  christos 
    139  1.1  christos     /* Read all tables within the file */
    140  1.1  christos 
    141  1.1  christos     while (ACPI_SUCCESS (Status))
    142  1.1  christos     {
    143  1.1  christos         /* Get one entire ACPI table */
    144  1.1  christos 
    145  1.1  christos         Status = AcGetOneTableFromFile (
    146  1.1  christos             Filename, File, GetOnlyAmlTables, &Table);
    147  1.1  christos 
    148  1.1  christos         if (Status == AE_CTRL_TERMINATE)
    149  1.1  christos         {
    150  1.1  christos             Status = AE_OK;
    151  1.1  christos             break;
    152  1.1  christos         }
    153  1.1  christos         else if (Status == AE_TYPE)
    154  1.1  christos         {
    155  1.1  christos             return (AE_OK);
    156  1.1  christos         }
    157  1.1  christos         else if (ACPI_FAILURE (Status))
    158  1.1  christos         {
    159  1.1  christos             return (Status);
    160  1.1  christos         }
    161  1.1  christos 
    162  1.1  christos         /* Print table header for iASL/disassembler only */
    163  1.1  christos 
    164  1.1  christos #ifdef ACPI_ASL_COMPILER
    165  1.1  christos 
    166  1.1  christos             AcpiTbPrintTableHeader (0, Table);
    167  1.1  christos #endif
    168  1.1  christos 
    169  1.1  christos         /* Allocate and link a table descriptor */
    170  1.1  christos 
    171  1.1  christos         TableDesc = AcpiOsAllocate (sizeof (ACPI_NEW_TABLE_DESC));
    172  1.1  christos         TableDesc->Table = Table;
    173  1.1  christos         TableDesc->Next = NULL;
    174  1.1  christos 
    175  1.1  christos         /* Link at the end of the local table list */
    176  1.1  christos 
    177  1.1  christos         if (!ListHead)
    178  1.1  christos         {
    179  1.1  christos             ListHead = TableDesc;
    180  1.1  christos             ListTail = TableDesc;
    181  1.1  christos         }
    182  1.1  christos         else
    183  1.1  christos         {
    184  1.1  christos             ListTail->Next = TableDesc;
    185  1.1  christos             ListTail = TableDesc;
    186  1.1  christos         }
    187  1.1  christos     }
    188  1.1  christos 
    189  1.1  christos     /* Add the local table list to the end of the global list */
    190  1.1  christos 
    191  1.1  christos     if (*ReturnListHead)
    192  1.1  christos     {
    193  1.1  christos         ListTail = *ReturnListHead;
    194  1.1  christos         while (ListTail->Next)
    195  1.1  christos         {
    196  1.1  christos             ListTail = ListTail->Next;
    197  1.1  christos         }
    198  1.1  christos 
    199  1.1  christos         ListTail->Next = ListHead;
    200  1.1  christos     }
    201  1.1  christos     else
    202  1.1  christos     {
    203  1.1  christos         *ReturnListHead = ListHead;
    204  1.1  christos     }
    205  1.1  christos 
    206  1.1  christos     fclose(File);
    207  1.1  christos     return (Status);
    208  1.1  christos }
    209  1.1  christos 
    210  1.1  christos 
    211  1.1  christos /*******************************************************************************
    212  1.1  christos  *
    213  1.1  christos  * FUNCTION:    AcGetOneTableFromFile
    214  1.1  christos  *
    215  1.1  christos  * PARAMETERS:  Filename            - File where table is located
    216  1.1  christos  *              File                - Open FILE pointer to Filename
    217  1.1  christos  *              GetOnlyAmlTables    - TRUE if the tables must be AML tables.
    218  1.1  christos  *              ReturnTable         - Where a pointer to the table is returned
    219  1.1  christos  *
    220  1.1  christos  * RETURN:      Status
    221  1.1  christos  *
    222  1.1  christos  * DESCRIPTION: Read the next ACPI table from a file. Implements support
    223  1.1  christos  *              for multiple tables within a single file. File must already
    224  1.1  christos  *              be open.
    225  1.1  christos  *
    226  1.1  christos  * Note: Loading an RSDP is not supported.
    227  1.1  christos  *
    228  1.1  christos  ******************************************************************************/
    229  1.1  christos 
    230  1.1  christos static ACPI_STATUS
    231  1.1  christos AcGetOneTableFromFile (
    232  1.1  christos     char                    *Filename,
    233  1.1  christos     FILE                    *File,
    234  1.1  christos     UINT8                   GetOnlyAmlTables,
    235  1.1  christos     ACPI_TABLE_HEADER       **ReturnTable)
    236  1.1  christos {
    237  1.1  christos     ACPI_STATUS             Status = AE_OK;
    238  1.1  christos     ACPI_TABLE_HEADER       TableHeader;
    239  1.1  christos     ACPI_TABLE_HEADER       *Table;
    240  1.1  christos     INT32                   Count;
    241  1.1  christos     long                    TableOffset;
    242  1.1  christos 
    243  1.1  christos 
    244  1.1  christos     *ReturnTable = NULL;
    245  1.1  christos 
    246  1.1  christos     /* Get the table header to examine signature and length */
    247  1.1  christos 
    248  1.1  christos     TableOffset = ftell (File);
    249  1.1  christos     Count = fread (&TableHeader, 1, sizeof (ACPI_TABLE_HEADER), File);
    250  1.1  christos     if (Count != sizeof (ACPI_TABLE_HEADER))
    251  1.1  christos     {
    252  1.1  christos         return (AE_CTRL_TERMINATE);
    253  1.1  christos     }
    254  1.1  christos 
    255  1.1  christos     /* Validate the table signature/header (limited ASCII chars) */
    256  1.1  christos 
    257  1.1  christos     Status = AcValidateTableHeader (File, TableOffset);
    258  1.1  christos     if (ACPI_FAILURE (Status))
    259  1.1  christos     {
    260  1.1  christos         return (Status);
    261  1.1  christos     }
    262  1.1  christos 
    263  1.1  christos     if (GetOnlyAmlTables)
    264  1.1  christos     {
    265  1.1  christos         /* Table must be an AML table (DSDT/SSDT) or FADT */
    266  1.1  christos 
    267  1.1  christos         if (!ACPI_COMPARE_NAME (TableHeader.Signature, ACPI_SIG_FADT) &&
    268  1.1  christos             !AcpiUtIsAmlTable (&TableHeader))
    269  1.1  christos         {
    270  1.1  christos             fprintf (stderr,
    271  1.1  christos                 "    %s: Table [%4.4s] is not an AML table - ignoring\n",
    272  1.1  christos                 Filename, TableHeader.Signature);
    273  1.1  christos 
    274  1.1  christos             return (AE_TYPE);
    275  1.1  christos         }
    276  1.1  christos     }
    277  1.1  christos 
    278  1.1  christos     /* Allocate a buffer for the entire table */
    279  1.1  christos 
    280  1.1  christos     Table = AcpiOsAllocate ((size_t) TableHeader.Length);
    281  1.1  christos     if (!Table)
    282  1.1  christos     {
    283  1.1  christos         return (AE_NO_MEMORY);
    284  1.1  christos     }
    285  1.1  christos 
    286  1.1  christos     /* Read the entire ACPI table, including header */
    287  1.1  christos 
    288  1.1  christos     fseek (File, TableOffset, SEEK_SET);
    289  1.1  christos 
    290  1.1  christos     Count = fread (Table, 1, TableHeader.Length, File);
    291  1.1  christos     if (Count != (INT32) TableHeader.Length)
    292  1.1  christos     {
    293  1.1  christos         Status = AE_ERROR;
    294  1.1  christos         goto ErrorExit;
    295  1.1  christos     }
    296  1.1  christos 
    297  1.1  christos     /* Validate the checksum (just issue a warning) */
    298  1.1  christos 
    299  1.1  christos     Status = AcpiTbVerifyChecksum (Table, TableHeader.Length);
    300  1.1  christos     if (ACPI_FAILURE (Status))
    301  1.1  christos     {
    302  1.1  christos         Status = AcCheckTextModeCorruption (Table);
    303  1.1  christos         if (ACPI_FAILURE (Status))
    304  1.1  christos         {
    305  1.1  christos             goto ErrorExit;
    306  1.1  christos         }
    307  1.1  christos     }
    308  1.1  christos 
    309  1.1  christos     *ReturnTable = Table;
    310  1.1  christos     return (AE_OK);
    311  1.1  christos 
    312  1.1  christos 
    313  1.1  christos ErrorExit:
    314  1.1  christos     AcpiOsFree (Table);
    315  1.1  christos     return (Status);
    316  1.1  christos }
    317  1.1  christos 
    318  1.1  christos 
    319  1.1  christos /*******************************************************************************
    320  1.1  christos  *
    321  1.1  christos  * FUNCTION:    AcIsFileBinary
    322  1.1  christos  *
    323  1.1  christos  * PARAMETERS:  File                - Open input file
    324  1.1  christos  *
    325  1.1  christos  * RETURN:      TRUE if file appears to be binary
    326  1.1  christos  *
    327  1.1  christos  * DESCRIPTION: Scan a file for any non-ASCII bytes.
    328  1.1  christos  *
    329  1.1  christos  * Note: Maintains current file position.
    330  1.1  christos  *
    331  1.1  christos  ******************************************************************************/
    332  1.1  christos 
    333  1.1  christos BOOLEAN
    334  1.1  christos AcIsFileBinary (
    335  1.1  christos     FILE                    *File)
    336  1.1  christos {
    337  1.1  christos     UINT8                   Byte;
    338  1.1  christos     BOOLEAN                 IsBinary = FALSE;
    339  1.1  christos     long                    FileOffset;
    340  1.1  christos 
    341  1.1  christos 
    342  1.1  christos     /* Scan entire file for any non-ASCII bytes */
    343  1.1  christos 
    344  1.1  christos     FileOffset = ftell (File);
    345  1.1  christos     while (fread (&Byte, 1, 1, File) == 1)
    346  1.1  christos     {
    347  1.1  christos         if (!isprint (Byte) && !isspace (Byte))
    348  1.1  christos         {
    349  1.1  christos             IsBinary = TRUE;
    350  1.1  christos             goto Exit;
    351  1.1  christos         }
    352  1.1  christos     }
    353  1.1  christos 
    354  1.1  christos Exit:
    355  1.1  christos     fseek (File, FileOffset, SEEK_SET);
    356  1.1  christos     return (IsBinary);
    357  1.1  christos }
    358  1.1  christos 
    359  1.1  christos 
    360  1.1  christos /*******************************************************************************
    361  1.1  christos  *
    362  1.1  christos  * FUNCTION:    AcValidateTableHeader
    363  1.1  christos  *
    364  1.1  christos  * PARAMETERS:  File                - Open input file
    365  1.1  christos  *
    366  1.1  christos  * RETURN:      Status
    367  1.1  christos  *
    368  1.1  christos  * DESCRIPTION: Determine if a file seems to contain one or more binary ACPI
    369  1.1  christos  *              tables, via the
    370  1.1  christos  *              following checks on what would be the table header:
    371  1.1  christos  *              1) File must be at least as long as an ACPI_TABLE_HEADER
    372  1.1  christos  *              2) There must be enough room in the file to hold entire table
    373  1.1  christos  *              3) Signature, OemId, OemTableId, AslCompilerId must be ASCII
    374  1.1  christos  *
    375  1.1  christos  * Note: There can be multiple definition blocks per file, so we cannot
    376  1.1  christos  * expect/compare the file size to be equal to the table length. 12/2015.
    377  1.1  christos  *
    378  1.1  christos  * Note: Maintains current file position.
    379  1.1  christos  *
    380  1.1  christos  ******************************************************************************/
    381  1.1  christos 
    382  1.1  christos ACPI_STATUS
    383  1.1  christos AcValidateTableHeader (
    384  1.1  christos     FILE                    *File,
    385  1.1  christos     long                    TableOffset)
    386  1.1  christos {
    387  1.1  christos     ACPI_TABLE_HEADER       TableHeader;
    388  1.1  christos     size_t                  Actual;
    389  1.1  christos     long                    OriginalOffset;
    390  1.1  christos     UINT32                  FileSize;
    391  1.1  christos     UINT32                  i;
    392  1.1  christos 
    393  1.1  christos 
    394  1.1  christos     ACPI_FUNCTION_TRACE ("AcValidateTableHeader");
    395  1.1  christos 
    396  1.1  christos 
    397  1.1  christos     /* Read a potential table header */
    398  1.1  christos 
    399  1.1  christos     OriginalOffset = ftell (File);
    400  1.1  christos     fseek (File, TableOffset, SEEK_SET);
    401  1.1  christos 
    402  1.1  christos     Actual = fread (&TableHeader, 1, sizeof (ACPI_TABLE_HEADER), File);
    403  1.1  christos     fseek (File, OriginalOffset, SEEK_SET);
    404  1.1  christos 
    405  1.1  christos     if (Actual < sizeof (ACPI_TABLE_HEADER))
    406  1.1  christos     {
    407  1.1  christos         return (AE_ERROR);
    408  1.1  christos     }
    409  1.1  christos 
    410  1.1  christos     /* Validate the signature (limited ASCII chars) */
    411  1.1  christos 
    412  1.1  christos     if (!AcpiIsValidSignature (TableHeader.Signature))
    413  1.1  christos     {
    414  1.1  christos         fprintf (stderr, "Invalid table signature: 0x%8.8X\n",
    415  1.1  christos             *ACPI_CAST_PTR (UINT32, TableHeader.Signature));
    416  1.1  christos         return (AE_BAD_SIGNATURE);
    417  1.1  christos     }
    418  1.1  christos 
    419  1.1  christos     /* Validate table length against bytes remaining in the file */
    420  1.1  christos 
    421  1.1  christos     FileSize = CmGetFileSize (File);
    422  1.1  christos     if (TableHeader.Length > (UINT32) (FileSize - TableOffset))
    423  1.1  christos     {
    424  1.1  christos         fprintf (stderr, "Table [%4.4s] is too long for file - "
    425  1.1  christos             "needs: 0x%.2X, remaining in file: 0x%.2X\n",
    426  1.1  christos             TableHeader.Signature, TableHeader.Length,
    427  1.1  christos             (UINT32) (FileSize - TableOffset));
    428  1.1  christos         return (AE_BAD_HEADER);
    429  1.1  christos     }
    430  1.1  christos 
    431  1.1  christos     /*
    432  1.1  christos      * These fields must be ASCII: OemId, OemTableId, AslCompilerId.
    433  1.1  christos      * We allow a NULL terminator in OemId and OemTableId.
    434  1.1  christos      */
    435  1.1  christos     for (i = 0; i < ACPI_NAME_SIZE; i++)
    436  1.1  christos     {
    437  1.1  christos         if (!ACPI_IS_ASCII ((UINT8) TableHeader.AslCompilerId[i]))
    438  1.1  christos         {
    439  1.1  christos             goto BadCharacters;
    440  1.1  christos         }
    441  1.1  christos     }
    442  1.1  christos 
    443  1.1  christos     for (i = 0; (i < ACPI_OEM_ID_SIZE) && (TableHeader.OemId[i]); i++)
    444  1.1  christos     {
    445  1.1  christos         if (!ACPI_IS_ASCII ((UINT8) TableHeader.OemId[i]))
    446  1.1  christos         {
    447  1.1  christos             goto BadCharacters;
    448  1.1  christos         }
    449  1.1  christos     }
    450  1.1  christos 
    451  1.1  christos     for (i = 0; (i < ACPI_OEM_TABLE_ID_SIZE) && (TableHeader.OemTableId[i]); i++)
    452  1.1  christos     {
    453  1.1  christos         if (!ACPI_IS_ASCII ((UINT8) TableHeader.OemTableId[i]))
    454  1.1  christos         {
    455  1.1  christos             goto BadCharacters;
    456  1.1  christos         }
    457  1.1  christos     }
    458  1.1  christos 
    459  1.1  christos     return (AE_OK);
    460  1.1  christos 
    461  1.1  christos 
    462  1.1  christos BadCharacters:
    463  1.1  christos 
    464  1.1  christos     ACPI_WARNING ((AE_INFO,
    465  1.1  christos         "Table header for [%4.4s] has invalid ASCII character(s)",
    466  1.1  christos         TableHeader.Signature));
    467  1.1  christos     return (AE_OK);
    468  1.1  christos }
    469  1.1  christos 
    470  1.1  christos 
    471  1.1  christos /*******************************************************************************
    472  1.1  christos  *
    473  1.1  christos  * FUNCTION:    AcCheckTextModeCorruption
    474  1.1  christos  *
    475  1.1  christos  * PARAMETERS:  Table           - Table buffer starting with table header
    476  1.1  christos  *
    477  1.1  christos  * RETURN:      Status
    478  1.1  christos  *
    479  1.1  christos  * DESCRIPTION: Check table for text mode file corruption where all linefeed
    480  1.1  christos  *              characters (LF) have been replaced by carriage return linefeed
    481  1.1  christos  *              pairs (CR/LF).
    482  1.1  christos  *
    483  1.1  christos  ******************************************************************************/
    484  1.1  christos 
    485  1.1  christos static ACPI_STATUS
    486  1.1  christos AcCheckTextModeCorruption (
    487  1.1  christos     ACPI_TABLE_HEADER       *Table)
    488  1.1  christos {
    489  1.1  christos     UINT32                  i;
    490  1.1  christos     UINT32                  Pairs = 0;
    491  1.1  christos     UINT8                   *Buffer = ACPI_CAST_PTR (UINT8, Table);
    492  1.1  christos 
    493  1.1  christos 
    494  1.1  christos     /* Scan entire table to determine if each LF has been prefixed with a CR */
    495  1.1  christos 
    496  1.1  christos     for (i = 1; i < Table->Length; i++)
    497  1.1  christos     {
    498  1.1  christos         if (Buffer[i] == 0x0A)
    499  1.1  christos         {
    500  1.1  christos             if (Buffer[i - 1] != 0x0D)
    501  1.1  christos             {
    502  1.1  christos                 /* The LF does not have a preceding CR, table not corrupted */
    503  1.1  christos 
    504  1.1  christos                 return (AE_OK);
    505  1.1  christos             }
    506  1.1  christos             else
    507  1.1  christos             {
    508  1.1  christos                 /* Found a CR/LF pair */
    509  1.1  christos 
    510  1.1  christos                 Pairs++;
    511  1.1  christos             }
    512  1.1  christos 
    513  1.1  christos             i++;
    514  1.1  christos         }
    515  1.1  christos     }
    516  1.1  christos 
    517  1.1  christos     if (!Pairs)
    518  1.1  christos     {
    519  1.1  christos         return (AE_OK);
    520  1.1  christos     }
    521  1.1  christos 
    522  1.1  christos     /*
    523  1.1  christos      * Entire table scanned, each CR is part of a CR/LF pair --
    524  1.1  christos      * meaning that the table was treated as a text file somewhere.
    525  1.1  christos      *
    526  1.1  christos      * NOTE: We can't "fix" the table, because any existing CR/LF pairs in the
    527  1.1  christos      * original table are left untouched by the text conversion process --
    528  1.1  christos      * meaning that we cannot simply replace CR/LF pairs with LFs.
    529  1.1  christos      */
    530  1.1  christos     AcpiOsPrintf ("Table has been corrupted by text mode conversion\n");
    531  1.1  christos     AcpiOsPrintf ("All LFs (%u) were changed to CR/LF pairs\n", Pairs);
    532  1.1  christos     AcpiOsPrintf ("Table cannot be repaired!\n");
    533  1.1  christos 
    534  1.1  christos     return (AE_BAD_VALUE);
    535  1.1  christos }
    536