<div dir="ltr">Hi,<div><br></div><div>I happened looked into this before. Raspberry Pi don't come with the rdtsc, so the code in Litmus^RT that's related to timing recording will need to be changed.</div><div><br></div>
<div>See:</div><div><a href="http://blog.remibergsma.com/2013/05/12/how-accurately-can-the-raspberry-pi-keep-time/">http://blog.remibergsma.com/2013/05/12/how-accurately-can-the-raspberry-pi-keep-time/</a><br></div><div><br>
</div><div><strong style="word-wrap:break-word;color:rgb(51,51,51);font-family:'Helvetica Neue',Helvetica,Arial,sans-serif;font-size:13px;line-height:18px">Rasberry Pi’s clocksource</strong><br style="word-wrap:break-word;color:rgb(51,51,51);font-family:'Helvetica Neue',Helvetica,Arial,sans-serif;font-size:13px;line-height:18px">
<span style="color:rgb(51,51,51);font-family:'Helvetica Neue',Helvetica,Arial,sans-serif;font-size:13px;line-height:18px">The Raspberry Pi does not ship with a TSC nor HPET counter to use as clocksource. Instead it relies on the STC that Raspbian presents as a clocksource. Based on the source code, “STC: a free running counter that increments at the rate of 1MHz”. This means it increments every microsecond.</span><br>
</div><div><span style="color:rgb(51,51,51);font-family:'Helvetica Neue',Helvetica,Arial,sans-serif;font-size:13px;line-height:18px"><br></span></div><div><span style="color:rgb(51,51,51);font-family:'Helvetica Neue',Helvetica,Arial,sans-serif;font-size:13px;line-height:18px">Hope this helps.</span><br>
</div><div><span style="color:rgb(51,51,51);font-family:'Helvetica Neue',Helvetica,Arial,sans-serif;font-size:13px;line-height:18px"><br></span></div><div><span style="color:rgb(51,51,51);font-family:'Helvetica Neue',Helvetica,Arial,sans-serif;font-size:13px;line-height:18px">Hi, Glenn:</span><br>
</div><div><span style="color:rgb(51,51,51);font-family:'Helvetica Neue',Helvetica,Arial,sans-serif;font-size:13px;line-height:18px"><br></span></div><div><font color="#333333" face="Helvetica Neue, Helvetica, Arial, sans-serif"><span style="line-height:18px">For Litmus on Cortex-A9 and ARM11, do you have any reference/publications to those works?</span></font></div>
<div><font color="#333333" face="Helvetica Neue, Helvetica, Arial, sans-serif"><span style="line-height:18px"><br></span></font></div><div><font color="#333333" face="Helvetica Neue, Helvetica, Arial, sans-serif"><span style="line-height:18px">Thanks.</span></font></div>
<div><br></div><div><span style="color:rgb(51,51,51);font-family:'Helvetica Neue',Helvetica,Arial,sans-serif;font-size:13px;line-height:18px">Sisu</span></div><div><span style="color:rgb(51,51,51);font-family:'Helvetica Neue',Helvetica,Arial,sans-serif;font-size:13px;line-height:18px"><br>
</span></div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Wed, Nov 6, 2013 at 2:55 PM, Glenn Elliott <span dir="ltr"><<a href="mailto:gelliott@cs.unc.edu" target="_blank">gelliott@cs.unc.edu</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div class="HOEnZb"><div class="h5">On Nov 6, 2013, at 3:20 PM, Ríad <<a href="mailto:riad.nassiffe@gmail.com">riad.nassiffe@gmail.com</a>> wrote:<br>
<br>
> Hi,<br>
><br>
> I would like to known if somebody had already compiled the litmus-rt for a raspberry pi device?<br>
><br>
> Thanks and Regards,<br>
> --<br>
> Ríad Mattos Nassiffe<br>
><br>
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<br>
I know that Litmus has been used on several Cortex-A9 implementations and an ARM11 MPCore development board. We routinely use Litmus on a Tegra3 platform here at UNC. However, I’m not sure if Litmus will compile “out-of-the-box” for all of these ARM platforms. I know for at least two of the Cortex-A9 boards, the developers had to take the Linux kernel source code distributed by the board manufacturers and rebase Litmus on top of it—the boards required Linux kernel changes that hadn’t yet appeared in mainline. However, this situation may have changed when Litmus was rebased on Linux 3.10.5. There’s no harm in giving it a try! I’d like to hear if you can get it working on Raspberry Pi and any problems you run into.<br>
<br>
-Glenn<br>
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</blockquote></div><br><br clear="all"><div><br></div>-- <br>Sisu Xi, PhD Candidate<br><br><a href="http://www.cse.wustl.edu/~xis/" target="_blank">http://www.cse.wustl.edu/~xis/</a><br>Department of Computer Science and Engineering<br>
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