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SharedIODescription
/ConfigRecord/Module/SharedDataRegions/SharedData/SharedIODescription
The SharedIODescription element is the root element of a SharedIODescription document that defines the configuration of a shared I/O region.
A shared I/O region is a memory area on the target that the platform provider can make available for access by applications in the CoreOSDescription document (see /CoreOSDescription/HardwareConfiguration/sharedIO). For example, the wrSbc750gx board has four user LEDs. If the platform provider has configured the platform to make the memory locations of the LEDs available as a shared I/O pool, the system integrator can configure a shared I/O region for access to those LEDs.
You create a SharedIODescription document as a file with SharedIODescription 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 shared I/O description as a separate file, you should begin with an XML declaration:
<?xml version="1.0" encoding="UTF-8"?>
Following the XML declaration, insert the SharedIODescription element:
<SharedIODescription 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" CachePolicy="DEFAULT" </SharedIODescription>
The SharedIODescription 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 SharedIODescription element. They are described below.
Required
None
None
The caching policy for the shared I/O region.
Optional
ConfigRecord
Unsigned 32 bit integer
A value of DEFAULT is used.
None
None
The core OS access rights for the shared I/O region. Note that the values of this attribute may be interpreted differently, or may not all be supported, on different target architectures.
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 I/O region.
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.
Generated on 2007-10-15 17:17:22.