A couple of questions about SPI

[Ewan Meadows]

I'm trying to get my DSerial (a slot-1 card with UART's) to talk with
DSLinux and I've got a couple of questions about the SPI bus, I am an
absolute noob when it comes to this so I could do with a few pointers:

>From what I can gather, I will need to map the Gamecard bus registers
to the ARM7 via EXMEMCNT:
http://nocash.emubase.de/gbatek.htm#dscartridgeioports

To do that I will have to write 1 to bit 11 of EXMEMCNT, would I do
this in head.S?
http://nocash.emubase.de/gbatek.htm#dsmemorycontrolcartridgesandmainram

I'm assuming that I want to put the SPI on the ARM7 as everything else
is on there and I couldn't see a way in linux-2.6.x/arch/arm/mach-nds/
to do it via the ARM9?  Would doing it this way conflict with other
things, like wifi/dldi?

My basic understanding at the moment is that I will have to put all
the functions to read/write to the DSerial in
arch/arm/mach-nds/arm7/spi.c and then create a driver in drivers/char

If anyone could point me in the right direction, that would be great.
I'm feeling a little out of my depth here but it's not going to stop
my trying!