BSP and Device Driver Development Guide
The file include/coverhd.h contains the overhead associated
with invoking each directive. This overhead consists of the execution
time required to package the parameters as well as to execute the "jump to
subroutine" and "return from subroutine" sequence. The intent of this
file is to help separate the calling overhead from the actual execution
time of a directive. This file is only used by the tests in the
RTEMS Timing Test Suite.
The numbers in this file are obtained by running the "Timer Overhead"
tmoverhd test. The numbers in this file may be 0 and no
overhead is subtracted from the directive execution times reported by
the Timing Suite.
There is a shared implementation of coverhd.h which sets all of
the overhead constants to 0. On faster processors, this is usually the
best alternative for the BSP as the calling overhead is extremely small.
This file is located at:
c/src/lib/libbsp/shared/include/coverhd.h
BSP and Device Driver Development Guide
Copyright © 1988-2008 OAR Corporation