The all Target and Component Dependency

Each component implements the <component>.all rule, which is defined in the component's Makefile.bin file. This rule tells you what other components this component is dependent upon. The <component>.all rule in the Makefile.src implements the rule, building the component in its own build directory. If this first component depends on a second component, the dependency rule

<component1>.all :: <component2>.all

If the dependency is valid only for the build process, the dependency rule is expressed in the Makefile.src file.