[U-Boot] "make clean" not traversing into board-specific directories?

[Joerg.Scheuermann at continental-corporation.com]

Hello,

I am using u-boot 2015.04 and have a mechanism implemented in the 
board-specific Makefile for our board,
which uses xsltproc to generate header-files from xml input files - this 
part is working by now.

what is still not working is the removal of those generated files upon 
calling "make clean",
and after some initial inspection I found out, that the board-specific 
directories are completely ignored when calling "make clean"!

- why is that the case, can't those directories not also be visited when 
cleaning things up?
- where and what would I need to change for being able to clean 
board-specific things, please?
(e.g. $BOARDDIR is empty for "make clean" - whereas it does contain the 
correct value for "make all")


Mit freundlichen Grüßen/Best regards,

Jörg Scheuermann