Mailing-List: contact cygwin-help AT sourceware DOT cygnus DOT com; run by ezmlm
List-Subscribe: <mailto:cygwin-subscribe AT sources DOT redhat DOT com>
List-Archive: <http://sources.redhat.com/ml/cygwin/>
List-Post: <mailto:cygwin AT sources DOT redhat DOT com>
List-Help: <mailto:cygwin-help AT sources DOT redhat DOT com>, <http://sources.redhat.com/ml/#faqs>
Sender: cygwin-owner AT sources DOT redhat DOT com
Delivered-To: mailing list cygwin AT sources DOT redhat DOT com
Date: Thu, 20 Sep 2001 09:12:50 +0200
From: Corinna Vinschen <cygwin AT cygwin DOT com>
To: cygwin AT cygwin DOT com
Subject: Re: dd, physical devices, permission denied
Message-ID: <20010920091250.B4194@cygbert.vinschen.de>
Mail-Followup-To: cygwin AT cygwin DOT com
References: <Pine DOT GSO DOT 4 DOT 33 DOT 0109191759320 DOT 14422-100000 AT brahms>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
User-Agent: Mutt/1.2.5i
In-Reply-To: <Pine.GSO.4.33.0109191759320.14422-100000@brahms>; from bastian@hc.ti.com on Wed, Sep 19, 2001 at 06:12:46PM -0500

On Wed, Sep 19, 2001 at 06:12:46PM -0500, Jeff Bastian wrote:
> 
> I see that the naming mechanism for drives has changed from //X to
> /cygdrive/X with the newest release.
> 
> However, I'm having problems with the raw disk devices themselves.
> 
> I was using Cygwin B20 until I upgraded today.  The old method
> doesn't work:
> 
>   [Administrator]$ dd if=dos622.img of=//./a:
>   dd: opening `//./a:': Bad address

Excerpt from the Online User's Guide:

http://cygwin.com/cygwin-ug-net/using-specialnames.html

  To access those devices you have to mount them and you have to use
  the posix name of the device to be recognized by Cygwin.

> So, I tried just 'a:' for the device, but it says permission denied:
> 
>   [Administrator]$ dd if=dos622.img of=a:
>   dd: opening `a:': Permission denied
> 
> Trying another method yields the same thing:
> 
>   [Administrator]$ mount -s -b a: /dev/fd0
>   mount: warning - /dev/fd0 does not exist.
>   [Administrator]$ dd if=dos622.img of=/dev/fd0
>   dd: opening `/dev/fd0': Permission denied

So you forgot to check the remaining method:

	mount -s -b //./a: /dev/fd0

I'm going to remove the need to mount the devices in one of the next
Cygwin versions but note that you will have to use the POSIX names
of the devices to get raw device support regardless.

Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Developer                                mailto:cygwin AT cygwin DOT com
Red Hat, Inc.

--
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
Bug reporting:         http://cygwin.com/bugs.html
Documentation:         http://cygwin.com/docs.html
FAQ:                   http://cygwin.com/faq/