Re: Accessing a hardware device

[Michael <macallan1888%gmail.com@localhost>]

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Hello,

On Mar 4, 2008, at 14:51, David Dudley wrote:

> How do I:
>
> 1.) Find the device (I know the PCI Vendor ID, and the board id)?

man 4 pci
You can mess with PCI devices via /dev/pci*, scan the bus(es), read  
BARs etc.

> 2.) Map the device into my memory space?

That's more difficult without a driver - in i386 you can just mmap(/ 
dev/mem, bussaddress) but you need options INSECURE in your kernel  
for that to work. On other machines bus- and memory-addresses may be  
different.

> 3.) I assume I have to release the device before exiting my program.
> How do I do that?

Not sure what you mean by that - I'd assume you map the registers  
exclusively, in that case you'd have to unmap them but that would  
happen anyway when your program exits.

have fun
Michael

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