BSP Developer's Guide

6
Components
! CAUTION: Do not alter the Wind River-supplied source configlette files in
target/config/comps/src. If necessary, use a BSP- or project-specific CDF to cancel
its declaration as CONFIGLETTES and to define BSP_STUB (available for Tornado
2.2 only) instead. A copy of the generic file is then placed into the BSP directory,
and it can be altered without impacting other BSPs, or changing the original file.
! CAUTION: Do not alter Wind River-supplied CDFs directly. Use the naming
convention to create a file whose higher precedence overrides the default
properties of Wind River-supplied components.
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6.4 Releasing Components
The process of releasing a Tornado component has been designed to preclude
modification of existing configuration files. New component description files
should be independent of existing files, with two exceptions:
■
New component objects must be bound into an existing folder or selection.
■
New component object initialization routines must be associated with an
existing initGroup.
A particular CDL convention makes it possible to bind a new component object to
an existing folder or selection and to an existing initGroup without modifying the
existing elements. By prepending an underscore (“_”) to certain component
properties, you can reverse the meaning of the property. For example, if there is
already a folder FOLDER_EXISTING and an initGroup initExisting, you can bind
a new component to them (without modifying them), as follows:
Component INCLUDE_FOO
...
_CHILDREN FOLDER_EXISTING
_INIT_ORDER initExisting
}
The property _CHILDREN has the opposite relationship to FOLDER_EXISTING as
CHILDREN; that is, _CHILDREN identifies the “parent.” In other words, it
produces the same effect as FOLDER_EXISTING having the component
INCLUDE_FOO on its list of children—without any modifications being made to
the CDF containing the FOLDER_EXISTING object.
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