Bug#738575: Access to a Galileo board
On Wed, Mar 12, 2014 at 10:07:43PM +0100, Thomas Karmann wrote:
> On 12.03.2014 (21:20), Aurelien Jarno wrote:
> > While it shows that the problem is at the CPU level, it's not really a
> > fix, as the bus is not locked anymore, so it might results in issues in
> > multithreaded solution.
> >
> > The correct solution would be to apply the solution from Intel, that is
> > adding a nop before every instruction with the lock prefix. This means
> > rebuilding the code.
>
> Yes, of course! I forgot to mention that I only did this to find the
> cause of the bug and to get Debian running somehow on the Galileo-Board.
>
> To my understanding the lock prefix only makes sense on multi-core
> systems, so the impatient (galileo users) should be safe by removing the
> prefix at every occurence until a proper fix is implemented?
For Galileo users yes, for Edison ones, no.
> About that: /proc/cpuinfo doesn't include a "microcode" entry, so I
> wouldn't bet on a quick fix by Intel. I don't know if this feature is
> really missing, though.
Let's wait a bit to see what happens on the Intel side before trying to
workaround that at the package level, especially having a more precise
description of which instruction sequence causes the issue in order to
not patch every instruction with the lock prefix if not needed.
--
Aurelien Jarno GPG: 1024D/F1BCDB73
aurelien@aurel32.net http://www.aurel32.net
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