[RTEMS Project] #3819: Consider FAA AC 20-148 - Reusable Software Components in RTEMS Software Engineering manual

RTEMS trac trac at rtems.org
Fri Nov 8 07:05:34 UTC 2019

#3819: Consider FAA AC 20-148 - Reusable Software Components in RTEMS Software
Engineering manual
  Reporter:  Sebastian Huber  |      Owner:  Sebastian Huber
      Type:  task             |     Status:  assigned
  Priority:  normal           |  Milestone:  5.1
 Component:  doc              |    Version:  5
  Severity:  normal           |   Keywords:
Blocked By:                   |   Blocking:
 Review of the Software Requirements Engineering chapter for the RTEMS
 Software Engineering manual suggested that we should take the
 FAA AC 20-148 - Reusable Software Components] into account:


     +Resources and Performance
     +Normally, resource and performance requirements are formulated like
     +* The resource U shall need less than V storage units.
     +* The operation Y shall complete within X time units.
     +Such statements are difficult to make for a software product like
 RTEMS which
     +runs on many different target platforms in various configurations.
 So, the
     +performance requirements of RTEMS shall be stated in terms of
 benchmarks.  The
     +benchmarks are run on the project-specific target platform and
     +The results obtained by the benchmark runs are reported in a human
     +presentation.  The application designer can then use the benchmark
 results to
     +determine if its system performance requirements are met.  The
 benchmarks shall
     +be executed under different environment conditions, e.g. varying
 cache states
     +(dirty, empty, valid) and system bus load generated by other
 processors.  The
     +application designer shall have the ability to add additional
     +conditions, e.g. system bus load by DMA engines or different system
     +arbitration schemes.
     +To catch resource and performance regressions via test suite runs
 there shall be
     +a means to specify threshold values for the measured quantities.  The
     +values should be provided for each validation platform.  How this can
 be done
     +and if the threshold values are maintained by the RTEMS Project is
 subject to

 We focused on big-O and whether methods were constant time, bounded, or
 when designing. Perhaps the focus could be there. But this is a design
 goal for all
 of RTEMS and something we would document. Nothing to do except a general
 design goal.

 This section also sounds like part of what is required by a systems
 when leveraging what the FAA calls a Reusable Software Component:


 You get credit for what's common and have to fill in details for your

Ticket URL: <http://devel.rtems.org/ticket/3819>
RTEMS Project <http://www.rtems.org/>
RTEMS Project

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