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
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