The idea of making the MOKO tab

[Al Johnson]

On Thursday 10 November 2011, SZENTE Balint wrote:
> On Thu, 10 Nov 2011 10:44:00 +0000
> 
> Al Johnson <openmoko at mazikeen.demon.co.uk> wrote:
> > That's about all you can expect with the current state of openness on
> > embedded GPUs. If you want acceleration you get a binary blob if
> > you're lucky. Mostly you're just SOL. There are hints that things are
> > moving slowly towards more openness, but that's about it. It's not
> > much better with embedded DSPs, though Ti seem to have a reasonably
> > open interface.
> > 
> > Do you know of a better alternative?
> 
> To be honest, I was not aware about this. I thought, the lack of
> specifications of Glamo chip is only a special case of the available
> embedded GPUs.

Quite the reverse - it's a special case that Openmoko managed to get docs that 
can be released to community devs for an open driver at all, even if they do 
have to sign an NDA. As a result it's got some of the best open support out 
there for a mobile GPU. That it doesn't work very well with a 640x480 screen 
is another matter entirely ;-)

> However, a possible (but more complex) alternative would be to avoid
> completely the existing proprietary GPU/DSP chips and make an FPGA
> based phone instead. Then we could use various open source hardware IP
> cores for CPU, GPU and whatever else is needed, similar to Milkymist,
> Open Graphics Project or Project VGA. That would be really cool.

Cool, but relatively expensive and power hungry. Any idea how many you need to 
be making before getting the design burned into silicon becomes cost 
effective?

> From my point of view a GPU is completely useless without drivers /
> specifications, thus practically it is not better at all from a basic
> VGA 2D accelerator IP core. At least an FPGA based open source IP core
> design *could be* improved in time without changing the PCB. Just think
> the possibilities. On the other hand, a closed unsupported GPU is dead
> from the start.

If you want a fast and efficient cpu with a good set of interfaces for making 
a phone or tablet they tend to have a gpu in them too, even if we can't use 
the acceleration at the moment. It's like things with an iPod dock - it's a 
useless feature for me, but something with one may still be better than 
something without for entirely separate reasons.