Re: [User-mode-linux-user] Best way to debug a device driver?

[Jeff D. <jd...@ka...>]

This just showed up on the kernel list.  This looks like a way of exposing 
hardware to a userspace driver.

				Jeff

Date: Tue, 18 Jul 2000 12:34:45 -0400
From: Brian Gerst <bg...@qu...>
To: George Anzinger <ge...@pi...>
Cc: "lin...@vg..." <lin...@vg...>
Subject: Re: Direct control of a device??

George Anzinger wrote:
> 
> Is there any way a linux user app can be given direct access to
> hardware? For example:
> * a simple driver is loaded.
> * the user land app sends an ioctl() to the driver.
> * the driver returns the beginning physical address of the pci device
>   we're interested in.
> * the user app calls something like "ioremap" to memory map the
>   registers of that device into its own space in order to be able to
>   directly do memory cycles to the device.
> 
> Thanks,

Do the ioremap in kernel space, then use mmap to export the registers to
user space.  An example of this is Device3Dfx, found at
http://linux.3dfx.com/open_source/download/voodoo3_banshee.htm