Hi, On 30.01.25 14:55, Ferenc Fejes wrote: > Hi, > > Is it possible to use the serial port for u-boot networking? For example, > given > a restricted environment where the FIT image is available with ethernet > firmware > and drivers, so it is not possible to boot it with DHCP boot since there is no > networking. Or simply the ethernet NIC has no u-boot driver at all. For such > cases, I assume ymodem is recommended to download and boot the FIT image. > > However, experimenting with different images and debugging, it would be more > convenient if serial could be used as both data and console channel. Is this > possible? > > A simple example: > 1. ppp on the host machine, with IP forward, NAT, etc. > 2. u-boot establish a ppp connection over serial to the host > 3. u-boot starts a netconsole session to the host > 4. user can use netconsole and wget to download images > > I was thinking of PPP, but that's probably not supported by u-boot. Anything > similar with RNDIS and USB CDC ACM? > > 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. 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 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 |
