[U-Boot] Rework the network stack

[Joe Hershberger]

Hi Jörg,

On Sat, Mar 21, 2015 at 3:33 AM, Jörg Krause <joerg.krause at embedded.rocks>
wrote:
>
> Hi all,
>
> there is an issue with the current network stack using netconsole. It's
> impossible to use network commands as TFTP inside netconsole, because
> they try to run as atomic network commands.
>
> The issue was already reported by Stefano Babic in 2010:
> [U-Boot] NetConsole and network API
> http://lists.denx.de/pipermail/u-boot/2010-August/075535.html

I worked around this problem here:

http://lists.denx.de/pipermail/u-boot/2012-August/129913.html

> I run into the same problem:
> [U-Boot] netconsole: USB Ethernet connection dropping with ping or
> tftpboot
> http://lists.denx.de/pipermail/u-boot/2015-February/203838.html

I didn't understand what about your case was not able to work given the
workaround I implemented previously. What was different about it?

> I have looked at the current network stack. The stack is based on the
> concept of atomic network commands. The implementation for netconsole
> looks very confusing.

There is no doubt that netconsole is quite confusing as it exists today.

> Sascha Hauer has reimplemented the network stack for Barebox:
> http://www.spinics.net/lists/u-boot-v2/msg00914.html
>
> Looking at the current implementation of net.c looks very clean and
> well-designed.

Thanks for pointing this out. I hadn't gone to look at the network stack in
barebox.

> What do you think about porting this to U-Boot?

I can look into this. Naturally there are many other changes to u-boot
network stack since the time barebox forked, so I expect such a port to be
very intensive... most likely a near complete rewrite of Sascha's series,
but I will investigate further.

Cheers,
-Joe