Mounting One of the memstick Image Files

[Warren Block]

On Thu, 21 Aug 2014, Martin G. McCormick wrote:

> 	Sometimes, one runs in to an amazing amount of trouble
> trying to do the simplest things. I need to modify
> FreeBSD-9.1-RELEASE-amd64-memstick.img to enable a serial
> console. It involves adding only one more line to
> /boot/loader.conf. Dirt simple, right? Well, maybe. I have a
> Debian system with USB ports and a virtual FreeBSD system hosted
> by a Mac. The USB ports on the Mac are not passed through to the
> FreeBSD VM and technical difficulties are likely to prevent me
> from modifying the VirtualBox VM to set this up. No, you don't
> want to hear that story.
>
> 	So, if I could mount FreeBSD-9.1-RELEASE-amd64-memstick.img, read/write,
> make the change, write back to the image and then copy the image
> back to the Debian system, I could still accomplish what needs
> to be done.
> 	I am sure the mount process is similar to mounting an
> ISO image, but what type description goes in the -t flag?

It is UFS, although Linux might call it something else.  However, the 
last time I looked, the memstick image used a "dangerously dedicated" 
bsdlabel partition, which might not be understood by non-BSD systems. 
It should be possible to skip over the bsdlabel sectors when mounting 
the filesystem, but I don't know how many blocks should be skipped.