Re: [ECOS] Help getting started: PCI/USB

[Andrew Lunn <andrew at lunn dot ch>]

On Thu, Apr 06, 2006 at 02:18:25PM -0700, stevemors@gmail.com wrote:
> Dear group,
> 
> I have been tasked with a project that involves a PCI-to-USB slave
> device on a PC platform. This is supposed to allow the PC to act as a
> USB slave. I'm trying to get my head around what all I need to do to
> get this up and running, while trying to understand eCos, and hope
> someone out there can shed some light. Here are some thoughts:
> 
> 1. Would the driver for this device be a USB driver wrapped in a PCI
> driver? Would I look at existing eCos PCI and USB drivers and create
> some sort of hybrid of these?

There is not really any PCI drivers. There are drivers which make use
of PCI, eg ethernet device drivers. Looking at a PCI ethernet driver
will give you the idea of how to find a PCI device, allocate it memory
etc.
 
> 2. The PC bios configures the PCI bus and devices. This means CPU-PCI
> address translation is unknown to eCos, correct? How can I fill in
> this information when this configuration has been skipped? (Doesn't
> redboot have to do this?)

I've never really studied PCI, but eCos does have the ability to
allocate resouces to devices etc. Only PC's have BIOS's. For the rest
of the world there is other ways to do it. 
 
> 3. Is this something that might be contributable to the eCos project
> when complete?

Sure, especially if you use a common PCI device. Do you have any idea
what it will be yet? Has the hardware been chosen?

        Andrew

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