Subject: Re: Sidewinder/3xp (txp) 3com ethernet cards on NetBSD 1.6.1 or 1.6-current
To: Brian Buhrow <>
From: Manuel Bouyer <>
List: tech-kern
Date: 06/14/2003 15:44:14
On Fri, Jun 13, 2003 at 05:42:18PM -0700, Brian Buhrow wrote:
> 	Hello.  I've started porting the txp(4) ethernet driver from OpenBSD
> to NetBSD-1.6.1, but find that it's a little more complex than I first
> anticipated.  I'm wondering if anyone else has done this work, or has some
> tips on how to deal with the onboard checksum capabilities on the cards.  I
> know we  have drivers if_elinkxl.c, which deal with onboard checksumming,
> but I don't quite understand how the activation of this feature works in
> the driver, and I'm not sure how to translate OpenBSD's handling of this
> feature to NetBSD.

You can also look at other drivers (like if_ti.c) which use it.
It's not too hard, the board publish its feature sets though
ifp->if_capabilities to the upper layer. The upper layer tells the
driver which capabilities should be used though ifp->if_capenable
(a change in this will also translate to a call to the ioctl routine).

You also have to set or look at the flags in the mbuf headers.

Manuel Bouyer <>
     NetBSD: 24 ans d'experience feront toujours la difference