[Cryptech Tech] arm

[Fredrik Thulin]

On Saturday, January 10, 2015 09:39:09 PM Hannes Tschofenig wrote:
> Hi Randy,
> 
> I work for ARM and could help you with your questions.

Great to have you on the list for this discussion! Although I'm only replying 
to a specific part of your e-mail I read it all with great interest and might 
return to it later on.
 
> In our group we have been working on mbed (and the next generation of
> mbed is currently work in progress), which we have announced at ARM
> TechCon last October.
> 
> Mbed is designed to work with the Cortex M process family.
> There are different types of processors available in that family, namely
> M0, M0+, M3, M4, and now also M7. The M7 was announced around ARM
> TechCon as well and aims to bridge the gap (in performance) between the
> Cortex M family in the Cortex A family.

Thanks for clearing that up. From the discussions we had in Stockholm last 
week about this I'd say we were leaning more towards the Cortex A family then, 
which is what we have today on the Novena (Freescale iMX6).

The reasons would be to not put something too small on the alpha board so that 
we end up having to worry about space constraints during development, and I 
guess also to have a high speed bus to the FPGA (dev environment uses 
Freescale EIM bus).

I do think that given compelling enough arguments we might re-evaluate this 
though. The one exception to this would be the tinfoil. If the thing loads 
something external to the SoC that we don't trust [1], we're going with 
another thing.

[1] Such as the Raspberry Pi closed source bootcode.bin 
http://www.raspberrypi.org/forums/viewtopic.php?f=7&t=5170

/Fredrik