On 6/9/07, Aaron Kaplan <aaron@lo-res.org> wrote:

On Jun 9, 2007, at 1:57 PM, Axel Neumann wrote:

> I am currently trying to get a grip on vnuml (
> http://www.dit.upm.es/vnumlwiki/index.php/Tutorial ) which has good
> howtos
> and tutorial for building host- and uml- kernels and root_fs.
> Especially vnuml offers a framework for virutal network
> configuration based on
> xml-configuration files. I think texas-kernel is also patched for
> vnuml
> enhancements but for texas's root_fs and network-configuration
> scripts I am
> not shure.
> Maybe aaron can provide some more background on that?
I _think_ zethix (in the CC) briefly looked into vnuml but it seemed
to complicated.
The scripts were all borked and quite unusable for us at least.

Yes, as far as I remember, vnuml needs a lot of things in order to work... well, things that all
linux distros usually have, but not busybox. It was something like ... install its boot scripts in the
vnuml'd system, make it mount an fs on the host, then use ssh for something and so on and so
on. But the biggest problem we had was actually... that it was constantly making our poor system
crash. Anyway, I guess we just had to drop it in order to move on. I do believe there are some nice
things about vnuml, but ...

> In order to releas texas from unproductive trial-and-error
> configuration
> testing (and feeling less intervening when applying core-kernel-
> patches or
> installing new system-libraries) I started to setup a small vnuml
> environment
> on my home-pc. Therefore I found also the following links quite
> useful:
> http://www.dit.upm.es/vnumlwiki/index.php/Installation
> http://www.enic.fr/people/landru/viminal/vnuml.gentoo/how-to/vnuml-
> gentoo-guide.html
> ( gentoo oriented setup, host-kernel-enhancement, uml-kernel,
> root_fs )
> http://www.dit.upm.es/vnumlwiki/index.php/Howto
> ( further links for root_fs howtos )
> @aaron:
> do you have a link explaining from-scratch busybox-based uml-rootfs
> generation
> (as being used on texas) ?

with an existing root_fs:

mount -o loop root_fs /mnt
then just copy over things as needed. That is what I did . works!

To create an initial root_fs:

dd if=/dev/zero of=roof_fs bs=1M count=XXX
Then mount this root_fs from inside an existing UML instance and
fdisk it (./linux ubd1=root_fs )
and mkfs it



zethix was recently working on a way to do the simulation completely
without UML but with olsr_switch
which has still some bugs. Maybe some similar batman_switch
application can be usefull?

Briefly, the olsr_switch works like this: in olsrd, there is this special 'driver' that doesn't use
a netif for transmission, but a tcp connection instead. that connection goes to the olsr_switch.
Also, there are some patches preventing all instances to modify the same routing table. So,
in order to make batman work with olsr_switch (or whatever) I guess modifications might be

There is also an N-th way of doing it, probably: pseudo interfaces (like tap) instead of
tcp connections. Nevertheless, all batmans (or olsrds) will share the same routing table.

there's no place like

Yes, there is - ::1, only bigger ;)