XO-2

Carl-Daniel Hailfinger c-d.hailfinger.devel.2006 at gmx.net
Thu May 22 10:12:35 EDT 2008


On 22.05.2008 15:38, C. Scott Ananian wrote:
> I'm not on the hardware team, so this is just a wild guess:
> [...]
> Some other features that have been discussed:
>  d) GPS (unknown whether this will be able to make the cost budget)
>   

This is not only a cost problem, but also a big power drain problem.
Besides that, GPS and GALILEO are similar enough that some manufacturers
claim they can support both with a software update. If a machine is
sitting in a deep valley, getting enough satellites into view for even
an inaccurate a position fix is a real challenge with only one satellite
fleet. Of course, having GPS in a school server will allow kids to
locate themselves on a world map with reasonable accuracy. Not perfect,
but better than nothing.

>  h) hardware-protected RTC (bitfrost desiderata)
>   

I'd be very interested in the reasons for that. P_THEFT is still mostly
unimplemented for cost reasons. A hardware-protected RTC will not
improve the current state at all as long as the hardware side of P_THEFT
is not implemented. It will certainly raise cost, though.

>  i) better protection for firmware FLASH, to avoid the possibility of
> bricking a machine if the power is removed at the wrong time.
>   

Protection for firmware flashing against bricking is easy if the flash
chip is big enough. OTOH, performing an update of EC microcode is a much
more difficult thing to protect against failure.

>  j) more open hardware design (schematic) -- this is really a
> contractual issue with the manufacturer
>   

This would certainly be cool.

>  k) more open software: we may not need an EC, and if we do we may be
> able to ensure its code is open.  We may change the wireless device,
> and/or be able to switch to open firmware for it.
>   

I believe item k) was already in the contracts with Quanta and Marvell,
unless the official announcements back then were wrong. It has been
stated repeatedly by OLPC officials that the only thing preventing a
full open source wireless firmware is the lack of time for porting the
code to another embedded OS. There were also statements like "We are
working with Quanta to release EC source code", so I think that's also
mostly a problem with lack of time.

Please correct me if I'm wrong.

Regards,
Carl-Daniel



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