[HH] proprietary CPUs

[Tom Metro]

Federico Lucifredi wrote:
>> Also, on the topic of openness, you should note that the Raspberry Pi
>> isn't an open design, and uses a proprietary CPU, possibly requiring
>> proprietary binary-only kernel drivers.
> 
> What do you mean by proprietary CPU here? It is a Broadcom SoC, but I
> don't see what's more proprietary there than a Freescale or Ti
> chip...

It may not be any worse or better. I'm just extrapolating based on what
you hear about Broadcom chips used in routers. In the latter case it is
well documented that the APIs for various bits of the chipset are kept
proprietary, such that you need to use binary drivers provided by the
chipset vendor. (This is one of the reasons you can't run FreeBSD on
consumer routers.)

I'm assuming the situation will be the same with the Broadcom chip used
on the Raspberry Pi. They'll provide a binary driver that you can freely
copy, so it'll be possible to port over other Linux distributions (as
we've seen happen) that can work with the same kernel as the vendor
supplied distribution, but if you want to do something more obscure,
you'll be out of luck.

I don't expect any CPU vendor to make the intellectual property for the
CPU internals public, but if you need an NDA just to write software for
it, or you need binary-only drivers, then I'd classify it as a
proprietary CPU.

I'd be curious to know how Freescale or TI fare in this area.


The other point I was making is that the Raspberry Pi board itself isn't
an open design, which seems a bit puzzling given the mission statement
of the organization. They seem to be trying to give the impression that
it is open, and maybe hinting that down the road it will be, but if I'm
not mistaken, unlike most of the other boards discussed, they don't
provide the schematics, bill of materials, or board layout.

Also, isn't the Broadcom SoC they are using proprietary in the sense
that you can't buy one through distribution, like you can with the TI
and Freescale parts? If so, that would make the idea of making your own
Raspberry Pi board pointless. (Maybe that's why the board design isn't
open yet.)

Maybe with the success of the Raspberry Pi, Broadcom will offer it as a
stock part. (I'm not sure Broadcom even sells through distribution. They
may only sell direct to high volume OEMs. At least for the SoCs. They
also make Ethernet controllers and more mundane commodity things that I
assume are sold through distributors.)

 -Tom