RE: Question about batman for ARM

[<cchien@creonexsystems.com>]

Hi Sven,

Thanks for the suggestions.
We were able to get Debian to boot up with batman enabled in raspberry-pi.

We would like to use batman with a custom radio and are trying to figure out what part of the source code we may need to modify to allow batman to work with a custom radio.
Custom radio means that the radio is not a commercial radio, such as wi-fi or Bluetooth.

The comments in the source code are limited and so we are wondering if you could suggest any resources and/or documentations that might provide more information to help us in what we are trying to do?

Regards,
Charles
____________
CreoNex Systems
2625 Townsgate Road, Suite 330 
Westlake Village, CA 91361
www.creonexsystems.com
(805) 558-9687
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-----Original Message-----
From: cchien@creonexsystems.com <cchien@creonexsystems.com> 
Sent: Friday, May 20, 2022 8:51 AM
To: 'Sven Eckelmann' <sven@narfation.org>
Cc: b.a.t.m.a.n@lists.open-mesh.org
Subject: RE: Question about batman for ARM


Hi Sven,

Thank you for the quick and informative response.
We will look into your suggestions.

Regards,
Charles
_____________
CreoNex Systems
2625 Townsgate Road, Suite 330
Westlake Village, CA 91320
www.creonexsystems.com
(805) 558-9687
This message (including any attachments) is for the named addressee(s)'s use only. It may contain sensitive, confidential, private proprietary or legally privileged information intended for a specific individual and purpose, and is protected by law. If you are not the intended recipient, please immediately delete it and all copies of it from your system, destroy any hard copies of it and notify the sender. Any use, disclosure, copying, or distribution of this message and/or any attachments is strictly prohibited.


-----Original Message-----
From: Sven Eckelmann <sven@narfation.org>
Sent: Friday, May 20, 2022 12:43 AM
To: Charles Chien <cchien@creonexsystems.com>
Cc: b.a.t.m.a.n@lists.open-mesh.org
Subject: Re: Question about batman for ARM

On Friday, 20 May 2022 08:18:45 CEST Charles Chien wrote:
> We’re currently trying to install batman-adv on an ARM platform but we 
> ran into some issues and we would appreciate your help to answer our 
> questions below:
> 
> Is the batman-adv module compatible with an ARM processor (Raspberry PI 4)?

There is not just an "ARM" processor. It is a family of various processors.

Anyway, it can be used easily on Raspberry Pi - just make sure that you use a good wifi device + driver (+firmware) which actually can communicate over IBSS/802.11s (without forwarding enabled) and has no (extreme low) peer limit. 
Unfortunately, you cannot take this for granted.

> I’m trying to install batman-adv onto an ARM Raspberry PI 4 with a 
> Debian based Linux distribution (Pop OS). However, when I run 
> “modprobe batman-adv”, it returns a FATAL error complaining that the 
> module is not found in the “/lib/modules” directory. Where can I 
> find/download the “.ko” for batman-adv for the ARM platform?

Ehrm, this is not how this works. You cannot just use a kernel module and hope that it works on all kernel (builds) available in the universe. This is also why we write following in each batman-adv release news entry: "As the kernel module always depends on the Linux kernel it is compiled against, it does not make sense to provide binaries on our website. As usual, you will find the signed tarballs in our download section:"

Either your distribution has to enable this module in their kernel build or you have to get their kernel headers (and build scripts) and then build it from scratch. And at least on the default Debian kernel, batman-adv is enabled since ages - so no idea why PopOS doesn't ship it

> And if I need to recompile the .ko file for ARM, is there an online 
> repository where I can find the original source code for the 
> batman-adv driver?

This is mentioned in multiple places on the website. Just to mention a few interesting pages:

* https://www.open-mesh.org/projects/open-mesh/wiki
* https://www.open-mesh.org/news/108
* https://www.open-mesh.org/projects/open-mesh/wiki/Download
* https://www.open-mesh.org/projects/open-mesh/wiki/UsingBatmanGit
* https://git.open-mesh.org/
  https://git.open-mesh.org/batman-adv.git
* https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/

Kind regards,
	Sven