u-boot in restricted environment: networking over serial

[Ahmad Fatoum]

Hi Ferenc,

On 03.02.25 13:31, Ferenc Fejes wrote:
> On Mon, 2025-02-03 at 13:08 +0100, Ahmad Fatoum wrote:
>> On 30.01.25 14:55, Ferenc Fejes wrote:
>>>
>>> Thanks in advance for any hint!
>>
>> If you are willing to implement it, there's RFC 916 (RATP), which
>> addresses the use case of establishing a reliable communication link over
>> serial. We use it in barebox to mount remote file systems via serial.
> 
> Thank you for the pointer, good to know barebox have such a feature! I assume
> the license permit what you suggest here, right?

barebox is licensed under the GPL-2.0 and IMO U-Boot would do well
to port over some of the generic niceties, which is why I am
pointing them out to prospective porters. :)

>> If you were to implement the same support in U-Boot, you could reuse
>> the host-side bits without change (and take inspiration from the barebox
>> implementation of the target-side bits).
>>
>> https://github.com/barebox/barebox/blob/master/fs/ratpfs.c
>> https://www.barebox.org/doc/latest/user/remote-control.html
> 
> I'll look into this. This looks like an interesting challenge or even better,
> add SoC bits to barebox (probably that is more work).

That would be cool. ;)
I got a Mediatek Chromebook that I intend to port barebox to (mt8186),
which possibly shares IPs with your router. But that's getting off-topic.

> BTW I have a MT7986 based router and I wanted to install Debian on it. In the
> process I encountered even though the ETH PHY supported by upstream, and linux-
> firmware have the required bits as well, none of them included in the installer.
> So I facing the same issue on Linux side as well :-) 

Meh, but surely, you can reach out to the Debian developers to get the necessary
drivers included.

> On FOSDEM '25 I noticed
> usb9pfs contribution from you, I really like that idea as well!

Thanks! There are some rough edges, but I believe this can be very useful once
the necessary parts land in diod, barebox et al.

Cheers,
Ahmad

> 
>>
>> Hope this helps.
>>
>> Cheers,
>> Ahmad
>>
>>
> 
> Best,
> Ferenc
> 


-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |