Exemplo n.º 1
0
static ACPI_STATUS
XfNamespaceLocateBegin (
    ACPI_PARSE_OBJECT       *Op,
    UINT32                  Level,
    void                    *Context)
{
    ACPI_WALK_STATE         *WalkState = (ACPI_WALK_STATE *) Context;
    ACPI_NAMESPACE_NODE     *Node;
    ACPI_STATUS             Status;
    ACPI_OBJECT_TYPE        ObjectType;
    char                    *Path;
    UINT8                   PassedArgs;
    ACPI_PARSE_OBJECT       *NextOp;
    ACPI_PARSE_OBJECT       *OwningOp;
    ACPI_PARSE_OBJECT       *SpaceIdOp;
    UINT32                  MinimumLength;
    UINT32                  Offset;
    UINT32                  FieldBitLength;
    UINT32                  TagBitLength;
    UINT8                   Message = 0;
    const ACPI_OPCODE_INFO  *OpInfo;
    UINT32                  Flags;
    ASL_METHOD_LOCAL        *MethodLocals = NULL;
    ASL_METHOD_LOCAL        *MethodArgs = NULL;
    int                     RegisterNumber;
    UINT32                  i;


    ACPI_FUNCTION_TRACE_PTR (XfNamespaceLocateBegin, Op);


    if ((Op->Asl.AmlOpcode == AML_METHOD_OP) && Op->Asl.Node)
    {
        Node = Op->Asl.Node;

        /* Support for method LocalX/ArgX analysis */

        if (!Node->MethodLocals)
        {
            /* Create local/arg info blocks */

            MethodLocals = UtLocalCalloc (
                sizeof (ASL_METHOD_LOCAL) * ACPI_METHOD_NUM_LOCALS);
            Node->MethodLocals = MethodLocals;

            MethodArgs = UtLocalCalloc (
                sizeof (ASL_METHOD_LOCAL) * ACPI_METHOD_NUM_ARGS);
            Node->MethodArgs = MethodArgs;

            /*
             * Get the method argument count
             * First, get the name node
             */
            NextOp = Op->Asl.Child;

            /* Get the NumArguments node */

            NextOp = NextOp->Asl.Next;
            Node->ArgCount = (UINT8)
                (((UINT8) NextOp->Asl.Value.Integer) & 0x07);

            /* We will track all possible ArgXs */

            for (i = 0; i < ACPI_METHOD_NUM_ARGS; i++)
            {
                if (i < Node->ArgCount)
                {
                    /* Real Args are always "initialized" */

                    MethodArgs[i].Flags = ASL_ARG_INITIALIZED;
                }
                else
                {
                    /* Other ArgXs can be used as locals */

                    MethodArgs[i].Flags = ASL_ARG_IS_LOCAL;
                }

                MethodArgs[i].Op = Op;
            }
        }
    }

    /*
     * If this node is the actual declaration of a name
     * [such as the XXXX name in "Method (XXXX)"],
     * we are not interested in it here. We only care about names that are
     * references to other objects within the namespace and the parent objects
     * of name declarations
     */
    if (Op->Asl.CompileFlags & OP_IS_NAME_DECLARATION)
    {
        return_ACPI_STATUS (AE_OK);
    }

    OpInfo = AcpiPsGetOpcodeInfo (Op->Asl.AmlOpcode);

    /* Check method LocalX variables */

    if (OpInfo->Type == AML_TYPE_LOCAL_VARIABLE)
    {
        /* Find parent method Op */

        NextOp = XfGetParentMethod (Op);
        if (!NextOp)
        {
            return_ACPI_STATUS (AE_OK);
        }

        /* Get method node */

        Node = NextOp->Asl.Node;

        RegisterNumber = Op->Asl.AmlOpcode & 0x0007; /* 0x60 through 0x67 */
        MethodLocals = Node->MethodLocals;

        if (Op->Asl.CompileFlags & OP_IS_TARGET)
        {
            /* Local is being initialized */

            MethodLocals[RegisterNumber].Flags |= ASL_LOCAL_INITIALIZED;
            MethodLocals[RegisterNumber].Op = Op;

            return_ACPI_STATUS (AE_OK);
        }

        /* Mark this Local as referenced */

        MethodLocals[RegisterNumber].Flags |= ASL_LOCAL_REFERENCED;
        MethodLocals[RegisterNumber].Op = Op;

        return_ACPI_STATUS (AE_OK);
    }

    /* Check method ArgX variables */

    if (OpInfo->Type == AML_TYPE_METHOD_ARGUMENT)
    {
        /* Find parent method Op */

        NextOp = XfGetParentMethod (Op);
        if (!NextOp)
        {
            return_ACPI_STATUS (AE_OK);
        }

        /* Get method node */

        Node = NextOp->Asl.Node;

        /* Get Arg # */

        RegisterNumber = Op->Asl.AmlOpcode - AML_ARG0; /* 0x68 through 0x6F */
        MethodArgs = Node->MethodArgs;

        /* Mark this Arg as referenced */

        MethodArgs[RegisterNumber].Flags |= ASL_ARG_REFERENCED;
        MethodArgs[RegisterNumber].Op = Op;

        if (Op->Asl.CompileFlags & OP_IS_TARGET)
        {
            /* Arg is being initialized */

            MethodArgs[RegisterNumber].Flags |= ASL_ARG_INITIALIZED;
        }

        return_ACPI_STATUS (AE_OK);
    }

    /*
     * After method ArgX and LocalX, we are only interested in opcodes
     * that have an associated name
     */
    if ((!(OpInfo->Flags & AML_NAMED)) &&
        (!(OpInfo->Flags & AML_CREATE)) &&
        (Op->Asl.ParseOpcode != PARSEOP_NAMESTRING) &&
        (Op->Asl.ParseOpcode != PARSEOP_NAMESEG)    &&
        (Op->Asl.ParseOpcode != PARSEOP_METHODCALL) &&
        (Op->Asl.ParseOpcode != PARSEOP_EXTERNAL))
    {
        return_ACPI_STATUS (AE_OK);
    }

    /*
     * One special case: CondRefOf operator - we don't care if the name exists
     * or not at this point, just ignore it, the point of the operator is to
     * determine if the name exists at runtime.
     */
    if ((Op->Asl.Parent) &&
        (Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_CONDREFOF))
    {
        return_ACPI_STATUS (AE_OK);
    }

    /*
     * We must enable the "search-to-root" for single NameSegs, but
     * we have to be very careful about opening up scopes
     */
    Flags = ACPI_NS_SEARCH_PARENT;
    if ((Op->Asl.ParseOpcode == PARSEOP_NAMESTRING) ||
        (Op->Asl.ParseOpcode == PARSEOP_NAMESEG)    ||
        (Op->Asl.ParseOpcode == PARSEOP_METHODCALL) ||
        (Op->Asl.ParseOpcode == PARSEOP_EXTERNAL))
    {
        /*
         * These are name references, do not push the scope stack
         * for them.
         */
        Flags |= ACPI_NS_DONT_OPEN_SCOPE;
    }

    /* Get the NamePath from the appropriate place */

    if (OpInfo->Flags & AML_NAMED)
    {
        /* For nearly all NAMED operators, the name reference is the first child */

        Path = Op->Asl.Child->Asl.Value.String;
        if (Op->Asl.AmlOpcode == AML_ALIAS_OP)
        {
            /*
             * ALIAS is the only oddball opcode, the name declaration
             * (alias name) is the second operand
             */
            Path = Op->Asl.Child->Asl.Next->Asl.Value.String;
        }
    }
    else if (OpInfo->Flags & AML_CREATE)
    {
        /* Name must appear as the last parameter */

        NextOp = Op->Asl.Child;
        while (!(NextOp->Asl.CompileFlags & OP_IS_NAME_DECLARATION))
        {
            NextOp = NextOp->Asl.Next;
        }

        Path = NextOp->Asl.Value.String;
    }
    else
    {
        Path = Op->Asl.Value.String;
    }

    ObjectType = AslMapNamedOpcodeToDataType (Op->Asl.AmlOpcode);
    ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
        "Type=%s\n", AcpiUtGetTypeName (ObjectType)));

    /*
     * Lookup the name in the namespace. Name must exist at this point, or it
     * is an invalid reference.
     *
     * The namespace is also used as a lookup table for references to resource
     * descriptors and the fields within them.
     */
    AslGbl_NsLookupCount++;

    Status = AcpiNsLookup (WalkState->ScopeInfo, Path, ObjectType,
        ACPI_IMODE_EXECUTE, Flags, WalkState, &Node);
    if (ACPI_FAILURE (Status))
    {
        if (Status == AE_NOT_FOUND)
        {
            /*
             * We didn't find the name reference by path -- we can qualify this
             * a little better before we print an error message
             */
            if (strlen (Path) == ACPI_NAME_SIZE)
            {
                /* A simple, one-segment ACPI name */

                if (XfObjectExists (Path))
                {
                    /*
                     * There exists such a name, but we couldn't get to it
                     * from this scope
                     */
                    AslError (ASL_ERROR, ASL_MSG_NOT_REACHABLE, Op,
                        Op->Asl.ExternalName);
                }
                else
                {
                    /* The name doesn't exist, period */

                    AslError (ASL_ERROR, ASL_MSG_NOT_EXIST,
                        Op, Op->Asl.ExternalName);
                }
            }
            else
            {
                /* The NamePath contains multiple NameSegs */

                if ((OpInfo->Flags & AML_CREATE) ||
                    (OpInfo->ObjectType == ACPI_TYPE_LOCAL_ALIAS))
                {
                    /*
                     * The new name is the last parameter. For the
                     * CreateXXXXField and Alias operators
                     */
                    NextOp = Op->Asl.Child;
                    while (!(NextOp->Asl.CompileFlags & OP_IS_NAME_DECLARATION))
                    {
                        NextOp = NextOp->Asl.Next;
                    }

                    AslError (ASL_ERROR, ASL_MSG_PREFIX_NOT_EXIST, NextOp,
                        NextOp->Asl.ExternalName);
                }
                else if (OpInfo->Flags & AML_NAMED)
                {
                    /* The new name is the first parameter */

                    AslError (ASL_ERROR, ASL_MSG_PREFIX_NOT_EXIST, Op,
                        Op->Asl.ExternalName);
                }
                else if (Path[0] == AML_ROOT_PREFIX)
                {
                    /* Full namepath from root, the object does not exist */

                    AslError (ASL_ERROR, ASL_MSG_NOT_EXIST, Op,
                        Op->Asl.ExternalName);
                }
                else
                {
                    /*
                     * Generic "not found" error. Cannot determine whether it
                     * doesn't exist or just can't be reached. However, we
                     * can differentiate between a NameSeg vs. NamePath.
                     */
                    if (strlen (Op->Asl.ExternalName) == ACPI_NAME_SIZE)
                    {
                        AslError (ASL_ERROR, ASL_MSG_NOT_FOUND, Op,
                            Op->Asl.ExternalName);
                    }
                    else
                    {
                        AslError (ASL_ERROR, ASL_MSG_NAMEPATH_NOT_EXIST, Op,
                            Op->Asl.ExternalName);
                    }
                }
            }

            Status = AE_OK;
        }

        return_ACPI_STATUS (Status);
    }

    /* Check for an attempt to access an object in another method */

    if (!XfValidateCrossReference (Op, OpInfo, Node))
    {
        AslError (ASL_ERROR, ASL_MSG_TEMPORARY_OBJECT, Op,
            Op->Asl.ExternalName);
        return_ACPI_STATUS (Status);
    }

    /* Object was found above, check for an illegal forward reference */

    if (Op->Asl.CompileFlags & OP_NOT_FOUND_DURING_LOAD)
    {
        /*
         * During the load phase, this Op was flagged as a possible
         * illegal forward reference
         *
         * Note: Allow "forward references" from within a method to an
         * object that is not within any method (module-level code)
         */
        if (!WalkState->ScopeInfo || (UtGetParentMethod (Node) &&
            !UtNodeIsDescendantOf (WalkState->ScopeInfo->Scope.Node,
                UtGetParentMethod (Node))))
        {
            AslError (ASL_ERROR, ASL_MSG_ILLEGAL_FORWARD_REF, Op,
                Op->Asl.ExternalName);
        }
    }

    /* Check for a reference vs. name declaration */

    if (!(OpInfo->Flags & AML_NAMED) &&
        !(OpInfo->Flags & AML_CREATE))
    {
        /* This node has been referenced, mark it for reference check */

        Node->Flags |= ANOBJ_IS_REFERENCED;
    }

    /* Attempt to optimize the NamePath */

    OptOptimizeNamePath (Op, OpInfo->Flags, WalkState, Path, Node);

    /*
     * 1) Dereference an alias (A name reference that is an alias)
     *    Aliases are not nested, the alias always points to the final object
     */
    if ((Op->Asl.ParseOpcode != PARSEOP_ALIAS) &&
        (Node->Type == ACPI_TYPE_LOCAL_ALIAS))
    {
        /* This node points back to the original PARSEOP_ALIAS */

        NextOp = Node->Op;

        /* The first child is the alias target op */

        NextOp = NextOp->Asl.Child;

        /* That in turn points back to original target alias node */

        if (NextOp->Asl.Node)
        {
            Node = NextOp->Asl.Node;
        }

        /* Else - forward reference to alias, will be resolved later */
    }

    /* 2) Check for a reference to a resource descriptor */

    if ((Node->Type == ACPI_TYPE_LOCAL_RESOURCE_FIELD) ||
        (Node->Type == ACPI_TYPE_LOCAL_RESOURCE))
    {
        /*
         * This was a reference to a field within a resource descriptor.
         * Extract the associated field offset (either a bit or byte
         * offset depending on the field type) and change the named
         * reference into an integer for AML code generation
         */
        Offset = Node->Value;
        TagBitLength = Node->Length;

        /*
         * If a field is being created, generate the length (in bits) of
         * the field. Note: Opcodes other than CreateXxxField and Index
         * can come through here. For other opcodes, we just need to
         * convert the resource tag reference to an integer offset.
         */
        switch (Op->Asl.Parent->Asl.AmlOpcode)
        {
        case AML_CREATE_FIELD_OP: /* Variable "Length" field, in bits */
            /*
             * We know the length operand is an integer constant because
             * we know that it contains a reference to a resource
             * descriptor tag.
             */
            FieldBitLength = (UINT32) Op->Asl.Next->Asl.Value.Integer;
            break;

        case AML_CREATE_BIT_FIELD_OP:

            FieldBitLength = 1;
            break;

        case AML_CREATE_BYTE_FIELD_OP:
        case AML_INDEX_OP:

            FieldBitLength = 8;
            break;

        case AML_CREATE_WORD_FIELD_OP:

            FieldBitLength = 16;
            break;

        case AML_CREATE_DWORD_FIELD_OP:

            FieldBitLength = 32;
            break;

        case AML_CREATE_QWORD_FIELD_OP:

            FieldBitLength = 64;
            break;

        default:

            FieldBitLength = 0;
            break;
        }

        /* Check the field length against the length of the resource tag */

        if (FieldBitLength)
        {
            if (TagBitLength < FieldBitLength)
            {
                Message = ASL_MSG_TAG_SMALLER;
            }
            else if (TagBitLength > FieldBitLength)
            {
                Message = ASL_MSG_TAG_LARGER;
            }

            if (Message)
            {
                sprintf (AslGbl_MsgBuffer,
                    "Size mismatch, Tag: %u bit%s, Field: %u bit%s",
                    TagBitLength, (TagBitLength > 1) ? "s" : "",
                    FieldBitLength, (FieldBitLength > 1) ? "s" : "");

                AslError (ASL_WARNING, Message, Op, AslGbl_MsgBuffer);
            }
        }

        /* Convert the BitOffset to a ByteOffset for certain opcodes */

        switch (Op->Asl.Parent->Asl.AmlOpcode)
        {
        case AML_CREATE_BYTE_FIELD_OP:
        case AML_CREATE_WORD_FIELD_OP:
        case AML_CREATE_DWORD_FIELD_OP:
        case AML_CREATE_QWORD_FIELD_OP:
        case AML_INDEX_OP:

            Offset = ACPI_DIV_8 (Offset);
            break;

        default:

            break;
        }

        /* Now convert this node to an integer whose value is the field offset */

        Op->Asl.AmlLength = 0;
        Op->Asl.ParseOpcode = PARSEOP_INTEGER;
        Op->Asl.Value.Integer = (UINT64) Offset;
        Op->Asl.CompileFlags |= OP_IS_RESOURCE_FIELD;

        OpcGenerateAmlOpcode (Op);
    }

    /* 3) Check for a method invocation */

    else if ((((Op->Asl.ParseOpcode == PARSEOP_NAMESTRING) || (Op->Asl.ParseOpcode == PARSEOP_NAMESEG)) &&
                (Node->Type == ACPI_TYPE_METHOD) &&
                (Op->Asl.Parent) &&
                (Op->Asl.Parent->Asl.ParseOpcode != PARSEOP_METHOD))   ||

                (Op->Asl.ParseOpcode == PARSEOP_METHODCALL))
    {
        /*
         * A reference to a method within one of these opcodes is not an
         * invocation of the method, it is simply a reference to the method.
         *
         * September 2016: Removed DeRefOf from this list
         */
        if ((Op->Asl.Parent) &&
            ((Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_REFOF)     ||
            (Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_PACKAGE)    ||
            (Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_VAR_PACKAGE)||
            (Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_OBJECTTYPE)))
        {
            return_ACPI_STATUS (AE_OK);
        }

        /*
         * There are two types of method invocation:
         * 1) Invocation with arguments -- the parser recognizes this
         *    as a METHODCALL.
         * 2) Invocation with no arguments --the parser cannot determine that
         *    this is a method invocation, therefore we have to figure it out
         *    here.
         */
        if (Node->Type != ACPI_TYPE_METHOD)
        {
            sprintf (AslGbl_MsgBuffer, "%s is a %s",
                Op->Asl.ExternalName, AcpiUtGetTypeName (Node->Type));

            AslError (ASL_ERROR, ASL_MSG_NOT_METHOD, Op, AslGbl_MsgBuffer);
            return_ACPI_STATUS (AE_OK);
        }

        /* Save the method node in the caller's op */

        Op->Asl.Node = Node;
        if (Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_CONDREFOF)
        {
            return_ACPI_STATUS (AE_OK);
        }

        /*
         * This is a method invocation, with or without arguments.
         * Count the number of arguments, each appears as a child
         * under the parent node
         */
        Op->Asl.ParseOpcode = PARSEOP_METHODCALL;
        UtSetParseOpName (Op);

        PassedArgs = 0;
        NextOp = Op->Asl.Child;

        while (NextOp)
        {
            PassedArgs++;
            NextOp = NextOp->Asl.Next;
        }

        if (Node->Value != ASL_EXTERNAL_METHOD &&
            Op->Asl.Parent->Asl.ParseOpcode != PARSEOP_EXTERNAL)
        {
            /*
             * Check the parsed arguments with the number expected by the
             * method declaration itself
             */
            if (PassedArgs != Node->Value)
            {
                sprintf (AslGbl_MsgBuffer, "%s requires %u", Op->Asl.ExternalName,
                    Node->Value);

                if (PassedArgs < Node->Value)
                {
                    AslError (ASL_ERROR, ASL_MSG_ARG_COUNT_LO, Op, AslGbl_MsgBuffer);
                }
                else
                {
                    AslError (ASL_ERROR, ASL_MSG_ARG_COUNT_HI, Op, AslGbl_MsgBuffer);
                }
            }
        }
    }

    /* 4) Check for an ASL Field definition */

    else if ((Op->Asl.Parent) &&
            ((Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_FIELD)     ||
             (Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_BANKFIELD)))
    {
        /*
         * Offset checking for fields. If the parent operation region has a
         * constant length (known at compile time), we can check fields
         * defined in that region against the region length. This will catch
         * fields and field units that cannot possibly fit within the region.
         *
         * Note: Index fields do not directly reference an operation region,
         * thus they are not included in this check.
         */
        if (Op == Op->Asl.Parent->Asl.Child)
        {
            /*
             * This is the first child of the field node, which is
             * the name of the region. Get the parse node for the
             * region -- which contains the length of the region.
             */
            OwningOp = Node->Op;
            Op->Asl.Parent->Asl.ExtraValue =
                ACPI_MUL_8 ((UINT32) OwningOp->Asl.Value.Integer);

            /* Examine the field access width */

            switch ((UINT8) Op->Asl.Parent->Asl.Value.Integer)
            {
            case AML_FIELD_ACCESS_ANY:
            case AML_FIELD_ACCESS_BYTE:
            case AML_FIELD_ACCESS_BUFFER:
            default:

                MinimumLength = 1;
                break;

            case AML_FIELD_ACCESS_WORD:

                MinimumLength = 2;
                break;

            case AML_FIELD_ACCESS_DWORD:

                MinimumLength = 4;
                break;

            case AML_FIELD_ACCESS_QWORD:

                MinimumLength = 8;
                break;
            }

            /*
             * Is the region at least as big as the access width?
             * Note: DataTableRegions have 0 length
             */
            if (((UINT32) OwningOp->Asl.Value.Integer) &&
                ((UINT32) OwningOp->Asl.Value.Integer < MinimumLength))
            {
                AslError (ASL_ERROR, ASL_MSG_FIELD_ACCESS_WIDTH, Op, NULL);
            }

            /*
             * Check EC/CMOS/SMBUS fields to make sure that the correct
             * access type is used (BYTE for EC/CMOS, BUFFER for SMBUS)
             */
            SpaceIdOp = OwningOp->Asl.Child->Asl.Next;
            switch ((UINT32) SpaceIdOp->Asl.Value.Integer)
            {
            case ACPI_ADR_SPACE_EC:
            case ACPI_ADR_SPACE_CMOS:
            case ACPI_ADR_SPACE_GPIO:

                if ((UINT8) Op->Asl.Parent->Asl.Value.Integer !=
                    AML_FIELD_ACCESS_BYTE)
                {
                    AslError (ASL_ERROR, ASL_MSG_REGION_BYTE_ACCESS, Op, NULL);
                }
                break;

            case ACPI_ADR_SPACE_SMBUS:
            case ACPI_ADR_SPACE_IPMI:
            case ACPI_ADR_SPACE_GSBUS:

                if ((UINT8) Op->Asl.Parent->Asl.Value.Integer !=
                    AML_FIELD_ACCESS_BUFFER)
                {
                    AslError (ASL_ERROR, ASL_MSG_REGION_BUFFER_ACCESS, Op, NULL);
                }
                break;

            default:

                /* Nothing to do for other address spaces */

                break;
            }
        }
        else
        {
            /*
             * This is one element of the field list. Check to make sure
             * that it does not go beyond the end of the parent operation region.
             *
             * In the code below:
             *    Op->Asl.Parent->Asl.ExtraValue      - Region Length (bits)
             *    Op->Asl.ExtraValue                  - Field start offset (bits)
             *    Op->Asl.Child->Asl.Value.Integer32  - Field length (bits)
             *    Op->Asl.Child->Asl.ExtraValue       - Field access width (bits)
             */
            if (Op->Asl.Parent->Asl.ExtraValue && Op->Asl.Child)
            {
                XfCheckFieldRange (Op,
                    Op->Asl.Parent->Asl.ExtraValue,
                    Op->Asl.ExtraValue,
                    (UINT32) Op->Asl.Child->Asl.Value.Integer,
                    Op->Asl.Child->Asl.ExtraValue);
            }
        }
    }

    /* 5) Check for a connection object */
#if 0
    else if (Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_CONNECTION)
    {
        return_ACPI_STATUS (Status);
    }
#endif

    Op->Asl.Node = Node;
    return_ACPI_STATUS (Status);
}
Exemplo n.º 2
0
static ACPI_STATUS
LkNamespaceLocateBegin (
    ACPI_PARSE_OBJECT       *Op,
    UINT32                  Level,
    void                    *Context)
{
    ACPI_WALK_STATE         *WalkState = (ACPI_WALK_STATE *) Context;
    ACPI_NAMESPACE_NODE     *Node;
    ACPI_STATUS             Status;
    ACPI_OBJECT_TYPE        ObjectType;
    char                    *Path;
    UINT8                   PassedArgs;
    ACPI_PARSE_OBJECT       *NextOp;
    ACPI_PARSE_OBJECT       *OwningOp;
    ACPI_PARSE_OBJECT       *SpaceIdOp;
    UINT32                  MinimumLength;
    UINT32                  Temp;
    const ACPI_OPCODE_INFO  *OpInfo;
    UINT32                  Flags;


    ACPI_FUNCTION_TRACE_PTR (LkNamespaceLocateBegin, Op);

    /*
     * If this node is the actual declaration of a name
     * [such as the XXXX name in "Method (XXXX)"],
     * we are not interested in it here.  We only care about names that are
     * references to other objects within the namespace and the parent objects
     * of name declarations
     */
    if (Op->Asl.CompileFlags & NODE_IS_NAME_DECLARATION)
    {
        return (AE_OK);
    }

    /* We are only interested in opcodes that have an associated name */

    OpInfo = AcpiPsGetOpcodeInfo (Op->Asl.AmlOpcode);

    if ((!(OpInfo->Flags & AML_NAMED)) &&
        (!(OpInfo->Flags & AML_CREATE)) &&
        (Op->Asl.ParseOpcode != PARSEOP_NAMESTRING) &&
        (Op->Asl.ParseOpcode != PARSEOP_NAMESEG)    &&
        (Op->Asl.ParseOpcode != PARSEOP_METHODCALL))
    {
        return (AE_OK);
    }

    /*
     * We must enable the "search-to-root" for single NameSegs, but
     * we have to be very careful about opening up scopes
     */
    Flags = ACPI_NS_SEARCH_PARENT;
    if ((Op->Asl.ParseOpcode == PARSEOP_NAMESTRING) ||
        (Op->Asl.ParseOpcode == PARSEOP_NAMESEG)    ||
        (Op->Asl.ParseOpcode == PARSEOP_METHODCALL))
    {
        /*
         * These are name references, do not push the scope stack
         * for them.
         */
        Flags |= ACPI_NS_DONT_OPEN_SCOPE;
    }

    /* Get the NamePath from the appropriate place */

    if (OpInfo->Flags & AML_NAMED)
    {
        /* For nearly all NAMED operators, the name reference is the first child */

        Path = Op->Asl.Child->Asl.Value.String;
        if (Op->Asl.AmlOpcode == AML_ALIAS_OP)
        {
            /*
             * ALIAS is the only oddball opcode, the name declaration
             * (alias name) is the second operand
             */
            Path = Op->Asl.Child->Asl.Next->Asl.Value.String;
        }
    }
    else if (OpInfo->Flags & AML_CREATE)
    {
        /* Name must appear as the last parameter */

        NextOp = Op->Asl.Child;
        while (!(NextOp->Asl.CompileFlags & NODE_IS_NAME_DECLARATION))
        {
            NextOp = NextOp->Asl.Next;
        }
        Path = NextOp->Asl.Value.String;
    }
    else
    {
        Path = Op->Asl.Value.String;
    }

    ObjectType = AslMapNamedOpcodeToDataType (Op->Asl.AmlOpcode);
    ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
        "Type=%s\n", AcpiUtGetTypeName (ObjectType)));

    /*
     * Lookup the name in the namespace.  Name must exist at this point, or it
     * is an invalid reference.
     *
     * The namespace is also used as a lookup table for references to resource
     * descriptors and the fields within them.
     */
    Gbl_NsLookupCount++;

    Status = AcpiNsLookup (WalkState->ScopeInfo, Path, ObjectType,
                ACPI_IMODE_EXECUTE, Flags, WalkState, &(Node));
    if (ACPI_FAILURE (Status))
    {
        if (Status == AE_NOT_FOUND)
        {
            /*
             * We didn't find the name reference by path -- we can qualify this
             * a little better before we print an error message
             */
            if (strlen (Path) == ACPI_NAME_SIZE)
            {
                /* A simple, one-segment ACPI name */

                if (LkObjectExists (Path))
                {
                    /*
                     * There exists such a name, but we couldn't get to it
                     * from this scope
                     */
                    AslError (ASL_ERROR, ASL_MSG_NOT_REACHABLE, Op,
                        Op->Asl.ExternalName);
                }
                else
                {
                    /* The name doesn't exist, period */

                    if ((Op->Asl.Parent) &&
                        (Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_CONDREFOF))
                    {
                        /* Ignore not found if parent is CondRefOf */

                        return (AE_OK);
                    }

                    AslError (ASL_ERROR, ASL_MSG_NOT_EXIST,
                        Op, Op->Asl.ExternalName);
                }
            }
            else
            {
                /* Check for a fully qualified path */

                if (Path[0] == AML_ROOT_PREFIX)
                {
                    /* Gave full path, the object does not exist */

                    if ((Op->Asl.Parent) &&
                        (Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_CONDREFOF))
                    {
                        /* Ignore not found if parent is CondRefOf */

                        return (AE_OK);
                    }

                    AslError (ASL_ERROR, ASL_MSG_NOT_EXIST, Op,
                        Op->Asl.ExternalName);
                }
                else
                {
                    /*
                     * We can't tell whether it doesn't exist or just
                     * can't be reached.
                     */
                    AslError (ASL_ERROR, ASL_MSG_NOT_FOUND, Op,
                        Op->Asl.ExternalName);
                }
            }

            Status = AE_OK;
        }
        return (Status);
    }

    /* Check for a reference vs. name declaration */

    if (!(OpInfo->Flags & AML_NAMED) &&
        !(OpInfo->Flags & AML_CREATE))
    {
        /* This node has been referenced, mark it for reference check */

        Node->Flags |= ANOBJ_IS_REFERENCED;
    }

    /* Attempt to optimize the NamePath */

    OptOptimizeNamePath (Op, OpInfo->Flags, WalkState, Path, Node);

    /*
     * 1) Dereference an alias (A name reference that is an alias)
     *    Aliases are not nested, the alias always points to the final object
     */
    if ((Op->Asl.ParseOpcode != PARSEOP_ALIAS) &&
        (Node->Type == ACPI_TYPE_LOCAL_ALIAS))
    {
        /* This node points back to the original PARSEOP_ALIAS */

        NextOp = Node->Op;

        /* The first child is the alias target op */

        NextOp = NextOp->Asl.Child;

        /* That in turn points back to original target alias node */

        if (NextOp->Asl.Node)
        {
            Node = NextOp->Asl.Node;
        }

        /* Else - forward reference to alias, will be resolved later */
    }

    /* 2) Check for a reference to a resource descriptor */

    if ((Node->Type == ACPI_TYPE_LOCAL_RESOURCE_FIELD) ||
             (Node->Type == ACPI_TYPE_LOCAL_RESOURCE))
    {
        /*
         * This was a reference to a field within a resource descriptor.  Extract
         * the associated field offset (either a bit or byte offset depending on
         * the field type) and change the named reference into an integer for
         * AML code generation
         */
        Temp = Node->Value;
        if (Node->Flags & ANOBJ_IS_BIT_OFFSET)
        {
            Op->Asl.CompileFlags |= NODE_IS_BIT_OFFSET;
        }

        /* Perform BitOffset <--> ByteOffset conversion if necessary */

        switch (Op->Asl.Parent->Asl.AmlOpcode)
        {
        case AML_CREATE_FIELD_OP:

            /* We allow a Byte offset to Bit Offset conversion for this op */

            if (!(Op->Asl.CompileFlags & NODE_IS_BIT_OFFSET))
            {
                /* Simply multiply byte offset times 8 to get bit offset */

                Temp = ACPI_MUL_8 (Temp);
            }
            break;


        case AML_CREATE_BIT_FIELD_OP:

            /* This op requires a Bit Offset */

            if (!(Op->Asl.CompileFlags & NODE_IS_BIT_OFFSET))
            {
                AslError (ASL_ERROR, ASL_MSG_BYTES_TO_BITS, Op, NULL);
            }
            break;


        case AML_CREATE_BYTE_FIELD_OP:
        case AML_CREATE_WORD_FIELD_OP:
        case AML_CREATE_DWORD_FIELD_OP:
        case AML_CREATE_QWORD_FIELD_OP:
        case AML_INDEX_OP:

            /* These Ops require Byte offsets */

            if (Op->Asl.CompileFlags & NODE_IS_BIT_OFFSET)
            {
                AslError (ASL_ERROR, ASL_MSG_BITS_TO_BYTES, Op, NULL);
            }
            break;


        default:
            /* Nothing to do for other opcodes */
            break;
        }

        /* Now convert this node to an integer whose value is the field offset */

        Op->Asl.AmlLength       = 0;
        Op->Asl.ParseOpcode     = PARSEOP_INTEGER;
        Op->Asl.Value.Integer   = (UINT64) Temp;
        Op->Asl.CompileFlags   |= NODE_IS_RESOURCE_FIELD;

        OpcGenerateAmlOpcode (Op);
    }

    /* 3) Check for a method invocation */

    else if ((((Op->Asl.ParseOpcode == PARSEOP_NAMESTRING) || (Op->Asl.ParseOpcode == PARSEOP_NAMESEG)) &&
                (Node->Type == ACPI_TYPE_METHOD) &&
                (Op->Asl.Parent) &&
                (Op->Asl.Parent->Asl.ParseOpcode != PARSEOP_METHOD))   ||

                (Op->Asl.ParseOpcode == PARSEOP_METHODCALL))
    {

        /*
         * A reference to a method within one of these opcodes is not an
         * invocation of the method, it is simply a reference to the method.
         */
        if ((Op->Asl.Parent) &&
           ((Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_REFOF)      ||
            (Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_DEREFOF)    ||
            (Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_OBJECTTYPE)))
        {
            return (AE_OK);
        }
        /*
         * There are two types of method invocation:
         * 1) Invocation with arguments -- the parser recognizes this
         *    as a METHODCALL.
         * 2) Invocation with no arguments --the parser cannot determine that
         *    this is a method invocation, therefore we have to figure it out
         *    here.
         */
        if (Node->Type != ACPI_TYPE_METHOD)
        {
            sprintf (MsgBuffer, "%s is a %s",
                    Op->Asl.ExternalName, AcpiUtGetTypeName (Node->Type));

            AslError (ASL_ERROR, ASL_MSG_NOT_METHOD, Op, MsgBuffer);
            return (AE_OK);
        }

        /* Save the method node in the caller's op */

        Op->Asl.Node = Node;
        if (Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_CONDREFOF)
        {
            return (AE_OK);
        }

        /*
         * This is a method invocation, with or without arguments.
         * Count the number of arguments, each appears as a child
         * under the parent node
         */
        Op->Asl.ParseOpcode = PARSEOP_METHODCALL;
        UtSetParseOpName (Op);

        PassedArgs = 0;
        NextOp     = Op->Asl.Child;

        while (NextOp)
        {
            PassedArgs++;
            NextOp = NextOp->Asl.Next;
        }

        if (Node->Value != ASL_EXTERNAL_METHOD)
        {
            /*
             * Check the parsed arguments with the number expected by the
             * method declaration itself
             */
            if (PassedArgs != Node->Value)
            {
                sprintf (MsgBuffer, "%s requires %d", Op->Asl.ExternalName,
                            Node->Value);

                if (PassedArgs < Node->Value)
                {
                    AslError (ASL_ERROR, ASL_MSG_ARG_COUNT_LO, Op, MsgBuffer);
                }
                else
                {
                    AslError (ASL_ERROR, ASL_MSG_ARG_COUNT_HI, Op, MsgBuffer);
                }
            }
        }
    }

    /* 4) Check for an ASL Field definition */

    else if ((Op->Asl.Parent) &&
            ((Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_FIELD)     ||
             (Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_BANKFIELD)))
    {
        /*
         * Offset checking for fields.  If the parent operation region has a
         * constant length (known at compile time), we can check fields
         * defined in that region against the region length.  This will catch
         * fields and field units that cannot possibly fit within the region.
         *
         * Note: Index fields do not directly reference an operation region,
         * thus they are not included in this check.
         */
        if (Op == Op->Asl.Parent->Asl.Child)
        {
            /*
             * This is the first child of the field node, which is
             * the name of the region.  Get the parse node for the
             * region -- which contains the length of the region.
             */
            OwningOp = Node->Op;
            Op->Asl.Parent->Asl.ExtraValue =
                ACPI_MUL_8 ((UINT32) OwningOp->Asl.Value.Integer);

            /* Examine the field access width */

            switch ((UINT8) Op->Asl.Parent->Asl.Value.Integer)
            {
            case AML_FIELD_ACCESS_ANY:
            case AML_FIELD_ACCESS_BYTE:
            case AML_FIELD_ACCESS_BUFFER:
            default:
                MinimumLength = 1;
                break;

            case AML_FIELD_ACCESS_WORD:
                MinimumLength = 2;
                break;

            case AML_FIELD_ACCESS_DWORD:
                MinimumLength = 4;
                break;

            case AML_FIELD_ACCESS_QWORD:
                MinimumLength = 8;
                break;
            }

            /*
             * Is the region at least as big as the access width?
             * Note: DataTableRegions have 0 length
             */
            if (((UINT32) OwningOp->Asl.Value.Integer) &&
                ((UINT32) OwningOp->Asl.Value.Integer < MinimumLength))
            {
                AslError (ASL_ERROR, ASL_MSG_FIELD_ACCESS_WIDTH, Op, NULL);
            }

            /*
             * Check EC/CMOS/SMBUS fields to make sure that the correct
             * access type is used (BYTE for EC/CMOS, BUFFER for SMBUS)
             */
            SpaceIdOp = OwningOp->Asl.Child->Asl.Next;
            switch ((UINT32) SpaceIdOp->Asl.Value.Integer)
            {
            case REGION_EC:
            case REGION_CMOS:

                if ((UINT8) Op->Asl.Parent->Asl.Value.Integer != AML_FIELD_ACCESS_BYTE)
                {
                    AslError (ASL_ERROR, ASL_MSG_REGION_BYTE_ACCESS, Op, NULL);
                }
                break;

            case REGION_SMBUS:

                if ((UINT8) Op->Asl.Parent->Asl.Value.Integer != AML_FIELD_ACCESS_BUFFER)
                {
                    AslError (ASL_ERROR, ASL_MSG_REGION_BUFFER_ACCESS, Op, NULL);
                }
                break;

            default:

                /* Nothing to do for other address spaces */
                break;
            }
        }
        else
        {
            /*
             * This is one element of the field list.  Check to make sure
             * that it does not go beyond the end of the parent operation region.
             *
             * In the code below:
             *    Op->Asl.Parent->Asl.ExtraValue      - Region Length (bits)
             *    Op->Asl.ExtraValue                  - Field start offset (bits)
             *    Op->Asl.Child->Asl.Value.Integer32  - Field length (bits)
             *    Op->Asl.Child->Asl.ExtraValue       - Field access width (bits)
             */
            if (Op->Asl.Parent->Asl.ExtraValue && Op->Asl.Child)
            {
                LkCheckFieldRange (Op,
                            Op->Asl.Parent->Asl.ExtraValue,
                            Op->Asl.ExtraValue,
                            (UINT32) Op->Asl.Child->Asl.Value.Integer,
                            Op->Asl.Child->Asl.ExtraValue);
            }
        }
    }

    Op->Asl.Node = Node;
    return (Status);
}