u-boot in restricted environment: networking over serial

[Ferenc Fejes]

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!

Best,
Ferenc