Re: Linux on IPAQ 214 (PXA310)

Kevin O'Connor wrote:
> On Sun, Mar 16, 2008 at 11:33:20AM +0000, Oliver Ford wrote:
>
>> Kevin O'Connor wrote:
>>
>>> Also, using the right cache flushing functions is crucial to working
>>> with "wirq". Is your haret detecting the machine as a pxa (and thus
>>> using the xscale cache flushes)?
>>>
>>>
>> Ah yes, that might be it. It is detecting it as a PXA but haret only has
>> support for the pxa2xx (xscale). I'm not sure how different the caching in
>> the pxa3xx, which I think is xscale3, is. For one, the xscale3 docs say it
>> has an L2 cache, although Eric Miao (on the kernel list) says the pxa310
>> doesn't, which seems to be correct from poking with the code. This leaves
>> me a little confused as to what is what.
>>
>
> It looks like there is a different cache flush for xscale3. See
> arch/arm/mm/proc-xsc3.S.
>
> I can bring over the cache function, but I need a reliable way to
> detect the processor. Do you know of a mechanism?
>
> If you have patches for haret, I'd like to see them. Ultimately, we
> should have one version of haret for all machines.
>
> -Kevin
>
My changes to haret are all over the place, and most of them are
temporary or just dumping lots of debugging info while I learnt about
how it all worked and what was going on. A lot of it was changes we made
to turn off more stuff in the hardware shut-down procedures and extra
cache clearing I tried adding to the assembly to stop the random memory
problems, but that just turned out to be the mapping and so isn't
necessary at all. Very little is actually needed to make the thing work.
When I've got somewhere with it all I'll put together a summary of
what's actually required, as well as a breakdown of the GPIOs for the
machine, the MFP configuration registers and how that all works.

 I seem to remember one of the coprocessor registers has the cpu id in
it and that might include the xScale3 ident, I'll look in the docs for
you at some point in the next few days, unless Vega has time to find it?

Meanwhile, I've got the bluetooth mostly working. I spent a lot of time
trying to reproduce the firmware upgrade that windows does. I can do
this but it doesn't quite behave the same so I've hit a bit of a dead
end with that. It turns out though, that the chip works without the
upgrade, and I can see it from my laptop. It won't respond to anything
until I get hcid of bluz-utils working, which in turn won't work without
dbus. D-Bus, which I'm quickly growing to hate, just seg-faults
immediately. I know very little about debugging linux seg-faults so this
may take me a little while.

Thanks all

Oliver
Received on Tue Mar 18 2008 - 19:49:34 EST