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SharedDataDescription
/ConfigRecord/Module/SharedDataRegions/SharedData/SharedDataDescription
The SharedDataDescription element is the root element of a SharedDataDescription document that defines the configuration of the shared data region.
You create SharedDataDescription document as a file with SharedDataDescription as its root element. You include the shared data configuration file into your system configuration using an xi:include element in the SharedData element. Optionally, you can include the shared data description inline in the SharedData element.
When creating a SharedDataDescription document as a separate file, you should begin with an XML declaration:
<?xml version="1.0" encoding="UTF-8"?>
Following the XML declaration, insert the SharedDataDescription element:
<SharedDataDescription xmlns="http://www.windriver.com/vxWorks653/ConfigRecord" xmlns:xi="http://www.w3.org/2001/XInclude" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.windriver.com/vxWorks653/ConfigRecord ../cleanschema/Application.xsd"> VirtualAddress="0x50001000" SystemAccess="READ_ONLY" DataType="DATABASE" CachePolicy="DEFAULT" Size="0x00001000"> </SharedDataDescription>
The SharedDataDescription element must include the required XML attributes that identify the schema and namespace for the document. The first three attributes are standard and should be entered exactly as shown. The xsi:schemaLocation attribute associates the namespace (http://www.windriver.com/vxWorks653/ConfigRecord) with the schema file (Application.xsd). You should provide the correct path to your copy of the schema. The location of the schema files in the install is installDir/vxworks653-2.2/target/config/xml/cleanschema.
If you use a schema-aware XML editor to create your files, it will probably create these attributes for you.
The other attributes shown are part of the SharedDataDescription element. They are described below.
Required
None
The caching policy for the shared data region. A setting of DEFAULT is usually, but not always, safe. Consult the BSP documentation, or the person who created the BSP, to determine the appropriate value.
Optional
ConfigRecord
Unsigned 32 bit integer
A value of DEFAULT is used.
None
None
The type of data contained in the shared data region. This is used to determine whether the boot loader will load the object file for the shared data region onto the target.
Optional
None
N/A
The shared data object file will not be loaded.
CONFIG_FILE: The shared data object file will be loaded.
DATABASE: The shared data object file will be loaded.
VIRTUAL: The shared data object file will not be loaded.
None
The size (in bytes) of the shared data region.
To minimize the impact of change on the configuration and certification on the shared data region and the module as a whole, you should size the shared data region to accommodate the largest reasonably foreseeable size of the shared data, rather than setting it to the minimum size required to accommodate the current shared data.
If you increase the size of the shared data region, you may also have to change the values of the following settings to accommodate the increased size of the shared data:
Required
ConfigRecord
Unsigned 32 bit integer
N/A
None
The upper bound is dependent on system configuration.
Determines whether the core OS has the right to access the shared data region.
The right of partitions to access a shared data region are configured using /ConfigRecord/Module/Partitions/Partition/PartitionDescription/SharedDataRegion. Note that the values of this attribute may be interpreted differently, or may not all be supported, on different target architectures. See your hardware documentation to determine what is supported on your target.
Optional
ConfigRecord
Signed 32 bit integer
The core OS has read and write access to the region.
NONE: The core OS has no access to the region.
READ_ONLY: The core OS has read-only access to the region.
READ_WRITE: The core OS has read and write access to the region.
WRITE_ONLY: The core OS has write-only access to the region.
For the PPC architecture, the value must be either READ_ONLY or READ_WRITE.
The virtual address of the shared data region.
To calculate a suitable virtual address for a shared data region, use the following procedure:
Optional
ConfigRecord
Unsigned 32 bit integer
The address is assigned at runtime.
0: The address is assigned at runtime.
The upper bound is dependent on system configuration.
The value must be a multiple of the CPU page size.
The location of the partition virtual address must be consistent with the rules for the placement of various types of memory regions on the target hardware. This means that it must not be located closer to an incompatible memory region than specified by CoreOSDescription/KernelConfiguration/@addressSpaceRegionAllocationUnit.
Generated on 2007-10-15 17:17:22.