Subject: Re: seek operation on devices
To: Stefan Sonnenberg-Carstens <>
From: Manuel Bouyer <>
List: tech-kern
Date: 03/23/2003 16:35:44
On Fri, Mar 21, 2003 at 02:09:46PM +0100, Stefan Sonnenberg-Carstens wrote:
> Hi List,
> I'm new to NetBSD kernel development and right now, I'm trying to get the
> big picture of how the NetBSD kernel works. (I did device driver programing on Linux befor).
> I followed some docs and found that a device driver (can/should) support these operations:
> open,close,probe,attach,read,write,ioctl - complete ?
> What about the seek operation ?

For block devices, the block number is in the argument to read or write;
seek is handled at a upper level.
For sequenctial devices such as tapes, seeks are handled by ioctls.

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