RTEMS CPU Architecture Supplement
The macro PPC_CACHE_ALIGNMENT is set to the line size of the cache. It is used to align the entry point of critical routines so that as much code as possible can be retrieved with the initial read into cache. This is done for the interrupt handler as well as the context switch routines.
In addition, the "shortcut" data structure used by the PowerPC implementation to ease access to data elements frequently accessed by RTEMS routines implemented in assembly language is aligned using this value.
RTEMS CPU Architecture Supplement
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