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Thomas,<br>
We have employed just this method (two distinct "applications" chosen
at boot time) on previous projects. Unfortunately, this project does
not have quite so clear a modal distinction between the two application
feature sets. And there is a case where both need to execute at the
same time. While I agree that the additional overhead for the inclusion
of "thread protection data" in the context switch would add some time,
I believe that the processor that we have chosen would have no trouble
keeping up. I am more interested in everyone's feeling about scope of
work, how much of the RTEMS kernel would be affected, etc. The other
piece that would need to be handled would be access exception handlers,
although this would be application specific.<br>
<br>
- Charlie<br>
<br>
Thomas Doerfler wrote:
<blockquote cite="mid:46852D9D.4050202@embedded-brains.de" type="cite">
<pre wrap="">Hi,
I would guess that adding sort of a protection layer (which should
include memory protection and others) would make the interaction between
various RTEMS and application modules much slower and complicated.
Maybe you might split your application differently: Wouldn't it be
possible to have two totally distinct applications, which are, let's
say, booted separatedly from Flash or CF disc?
One would be FAA approved for the flight level, and for data retrival,
you might switch to the other application which includes the USB stack?
wkr,
Thomas.
Charles Steaderman schrieb:
</pre>
<blockquote type="cite">
<pre wrap="">I am working on developing an avionics application using an Atmel ARM9
CPU. Part of the functionality of the application will be developed and
verified to FAA Level C (core data collection and storage), while other
aspects of the application (ground based I/O via USB) would not require
certification. A primary reason for not wanting to certify the ground
based code is to avoid certifying the USB stack. I know that RTEMS does
not presently provide task level execution and access privilege
management, but my questions are:
1. Is it reasonable to add this capability to RTEMS?
2. Has anyone already done this?
3. Any guesstimate about the effort needed to implement this?
- Charlie
--
Charlie Steaderman
<a class="moz-txt-link-abbreviated" href="mailto:charlies@poliac.com">charlies@poliac.com</a>
VP Engineering
Poliac Research Corporation
Phone: 952.707.6245
Cell: 612.242.6364
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</pre>
</blockquote>
<pre wrap=""><!---->
</pre>
</blockquote>
<br>
<pre class="moz-signature" cols="72">--
Charlie Steaderman
<a class="moz-txt-link-abbreviated" href="mailto:charlies@poliac.com">charlies@poliac.com</a>
VP Engineering
Poliac Research Corporation
Phone: 952.707.6245
Cell: 612.242.6364</pre>
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