08/04/2004 18:42:51, Wookey <wookey@aleph1.co.uk> wrote:

>There are lots of things one could usefully write about ballon to 
help
>people grok it but a couple of the most basic are 
>1) a list of the GPIOs and what they are assigned to on particular 
variants

Yes - this is actually documented in the backplane board. I'll 
export it into clear text this weekend. Some prototype code to 
show how to twiddle the GPIOs and PLD resources from linux 
would also be handy, for those of us on the hardware side. Such 
things, while obvious to softies, are utterly unguessable :)

>2) a memory map

It's easy enough to generate a hardware memory map - not least 
because it's an unavoidable consequence of the SA1110. 
However, having it documented in easy-to-find text would be 
handy. The problem is, after the OS and MMU have been at it, 
who knows where anything is? I certainly don't. 2 different chunks 
of documentation needed. 

>3) Some info on why it is designed the way it is (I had someone 
pointing out
>that balloon was very cool - but they really want to understand 
the design
>descisions made as well as just looking at the schemeatic). Why 
this
>particular driver chip, etc. Some notes steve? 

Yep - will do. The general purpose answer is "to make it mostly 
compatable with iPaqs, to reduce software hassles", and "because 
that's the way the SA1110 requires it". Once those two are 
satisfied, there's not much leeway. I'll generate something rather 
more complete, though - there are certainly some twiddly bits that 
deserve a bit of explanation. 

Steve