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28 TITLE="Coarse-grained Configuration"
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65 >Chapter 28. Manual Configuration</TD
71 HREF="coarse-grained-configuration.html"
85 NAME="ECOS-PACKAGES">Packages</H1
90 > is a component architecture. The system comes as a
91 number of packages which can be
92 enabled or disabled as required, and new packages can be
93 added as they become available. Unfortunately, the packages
94 are not completely independent: for example the µITRON
95 compatibility package relies almost entirely on
96 functionality provided by the kernel package, and it would
97 not make sense to try to build µITRON if the kernel
98 was disabled. The C library has fewer dependencies: some
99 parts of the C library rely on kernel functionality, but it
100 is possible to disable these parts and thus build a system
101 that has the C library but no kernel. The
105 > tool has the capability of
106 checking that all the dependencies are satisfied, but it
107 may still be possible to produce configurations that will
108 not build or (conceivably) that will build but not run.
109 Developers should be aware of this and take appropriate
116 include all packages that are appropriate for the specified hardware
117 in the configuration. The common HAL package and
121 > infrastructure must be present in every configuration. In
122 addition, it is always necessary to have one architectural HAL package
123 and one platform HAL package. Other packages are optional, and can
124 be added or removed from a configuration as required.</P
126 >The application may not require all of the packages; for example,
127 it might not need the µITRON compatibility
128 package, or the floating point support provided by the math library.
129 There is a slight overhead when <SPAN
132 > is built because the packages
133 will get compiled, and there is also a small disk space penalty.
134 However, any unused facilities will get stripped out at link-time,
135 so having redundant packages will not affect the final executable. </P
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181 >Building the System</TD
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195 >Coarse-grained Configuration</TD