Subject: Re: Window Manager?
To: None <firstname.lastname@example.org>
From: Robert Swindells <email@example.com>
Date: 10/24/2002 23:23:05
Herb Peyerl wrote:
>actually, I was thinking about a USB keyboard but I'm betting the J720
>is a USB Device, not host. Or heck, a USB Mouse... but ah well. I know
>the intent is to be portable but sometimes you just want a real keyboard
The Jornada 720 has the SA1111 companion chip which contains an OHCI
USB host controller. I don't know whether it is brought out to an
external connector though as I don't own a J720.
There is a bug in the SA1111 that means that it can only do bus
master DMA into the first ~1M of RAM, depending on SDRAM type. There
isn't a PIO interface to the USB controller.
To get this to work we would need to add a bounce buffer implementation
and either move the kernel start address up, or create some hole fairly
near the start of it.
I have got a SA1111 OHCI attachment file which attaches the generic
ohci driver, but I haven't written the bounce buffer stuff.