[U-Boot] Obtaining board specific phy diagnostics

Hi all,

Is there a common mechanism to hook in board specific ethernet phy commands? For example, I'd like to hook in the ability to read the TDR characteristics of the ethernet cable connected to my board. I know the phy on my board supports this so I was planning on hooking it into the mii command set somehow.

Currently, the ethernet set up code registers phy read and write routines, but that is all. Is there a recognised method / approach to add such board specific commands/features into an existing 'common' command?

Cheers, -- Matt