exnames.c

acpi tools for linux include acpiexec and acpixtract

        Index++)
    {
        CharBuf[Index] = *AmlAddress++;
        ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "%c\n", CharBuf[Index]));
    }


    /* Valid name segment  */

    if (Index == 4)
    {
        /* Found 4 valid characters */

        CharBuf[4] = '\0';

        if (NameString)
        {
            ACPI_STRCAT (NameString, CharBuf);
            ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
                "Appended to - %s\n", NameString));
        }
        else
        {
            ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
                "No Name string - %s\n", CharBuf));
        }
    }
    else if (Index == 0)
    {
        /*
         * First character was not a valid name character,
         * so we are looking at something other than a name.
         */
        ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
            "Leading character is not alpha: %02Xh (not a name)\n",
            CharBuf[0]));
        Status = AE_CTRL_PENDING;
    }
    else
    {
        /*
         * Segment started with one or more valid characters, but fewer than
         * the required 4
         */
        Status = AE_AML_BAD_NAME;
        ACPI_ERROR ((AE_INFO,
            "Bad character %02x in name, at %p",
            *AmlAddress, AmlAddress));
    }

    *InAmlAddress = ACPI_CAST_PTR (UINT8, AmlAddress);
    return_ACPI_STATUS (Status);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiExGetNameString
 *
 * PARAMETERS:  DataType            - Object type to be associated with this
 *                                    name
 *              InAmlAddress        - Pointer to the namestring in the AML code
 *              OutNameString       - Where the namestring is returned
 *              OutNameLength       - Length of the returned string
 *
 * RETURN:      Status, namestring and length
 *
 * DESCRIPTION: Extract a full namepath from the AML byte stream,
 *              including any prefixes.
 *
 ******************************************************************************/

ACPI_STATUS
AcpiExGetNameString (
    ACPI_OBJECT_TYPE        DataType,
    UINT8                   *InAmlAddress,
    char                    **OutNameString,
    UINT32                  *OutNameLength)
{
    ACPI_STATUS             Status = AE_OK;
    UINT8                   *AmlAddress = InAmlAddress;
    char                    *NameString = NULL;
    UINT32                  NumSegments;
    UINT32                  PrefixCount = 0;
    BOOLEAN                 HasPrefix = FALSE;


    ACPI_FUNCTION_TRACE_PTR (ExGetNameString, AmlAddress);


    if (ACPI_TYPE_LOCAL_REGION_FIELD == DataType   ||
        ACPI_TYPE_LOCAL_BANK_FIELD == DataType     ||
        ACPI_TYPE_LOCAL_INDEX_FIELD == DataType)
    {
        /* Disallow prefixes for types associated with FieldUnit names */

        NameString = AcpiExAllocateNameString (0, 1);
        if (!NameString)
        {
            Status = AE_NO_MEMORY;
        }
        else
        {
            Status = AcpiExNameSegment (&AmlAddress, NameString);
        }
    }
    else
    {
        /*
         * DataType is not a field name.
         * Examine first character of name for root or parent prefix operators
         */
        switch (*AmlAddress)
        {
        case AML_ROOT_PREFIX:

            ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "RootPrefix(\\) at %p\n",
                AmlAddress));

            /*
             * Remember that we have a RootPrefix --
             * see comment in AcpiExAllocateNameString()
             */
            AmlAddress++;
            PrefixCount = ACPI_UINT32_MAX;
            HasPrefix = TRUE;
            break;


        case AML_PARENT_PREFIX:

            /* Increment past possibly multiple parent prefixes */

            do
            {
                ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "ParentPrefix (^) at %p\n",
                    AmlAddress));

                AmlAddress++;
                PrefixCount++;

            } while (*AmlAddress == AML_PARENT_PREFIX);

            HasPrefix = TRUE;
            break;


        default:

            /* Not a prefix character */

            break;
        }

        /* Examine first character of name for name segment prefix operator */

        switch (*AmlAddress)
        {
        case AML_DUAL_NAME_PREFIX:

            ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "DualNamePrefix at %p\n",
                AmlAddress));

            AmlAddress++;
            NameString = AcpiExAllocateNameString (PrefixCount, 2);
            if (!NameString)
            {
                Status = AE_NO_MEMORY;
                break;
            }

            /* Indicate that we processed a prefix */

            HasPrefix = TRUE;

            Status = AcpiExNameSegment (&AmlAddress, NameString);
            if (ACPI_SUCCESS (Status))
            {
                Status = AcpiExNameSegment (&AmlAddress, NameString);
            }
            break;


        case AML_MULTI_NAME_PREFIX_OP:

            ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "MultiNamePrefix at %p\n",
                AmlAddress));

            /* Fetch count of segments remaining in name path */

            AmlAddress++;
            NumSegments = *AmlAddress;

            NameString = AcpiExAllocateNameString (PrefixCount, NumSegments);
            if (!NameString)
            {
                Status = AE_NO_MEMORY;
                break;
            }

            /* Indicate that we processed a prefix */

            AmlAddress++;
            HasPrefix = TRUE;

            while (NumSegments &&
                    (Status = AcpiExNameSegment (&AmlAddress, NameString)) ==
                        AE_OK)
            {
                NumSegments--;
            }

            break;


        case 0:

            /* NullName valid as of 8-12-98 ASL/AML Grammar Update */

            if (PrefixCount == ACPI_UINT32_MAX)
            {
                ACPI_DEBUG_PRINT ((ACPI_DB_EXEC,
                    "NameSeg is \"\\\" followed by NULL\n"));
            }

            /* Consume the NULL byte */

            AmlAddress++;
            NameString = AcpiExAllocateNameString (PrefixCount, 0);
            if (!NameString)
            {
                Status = AE_NO_MEMORY;
                break;
            }

            break;


        default:

            /* Name segment string */

            NameString = AcpiExAllocateNameString (PrefixCount, 1);
            if (!NameString)
            {
                Status = AE_NO_MEMORY;
                break;
            }

            Status = AcpiExNameSegment (&AmlAddress, NameString);
            break;
        }
    }

    if (AE_CTRL_PENDING == Status && HasPrefix)
    {
        /* Ran out of segments after processing a prefix */

        ACPI_ERROR ((AE_INFO,
            "Malformed Name at %p", NameString));
        Status = AE_AML_BAD_NAME;
    }

    if (ACPI_FAILURE (Status))
    {
        if (NameString)
        {
            ACPI_FREE (NameString);
        }
        return_ACPI_STATUS (Status);
    }

    *OutNameString = NameString;
    *OutNameLength = (UINT32) (AmlAddress - InAmlAddress);

    return_ACPI_STATUS (Status);
}