deriving BSP from powerpc/shared

[Till Straumann]

I have problems with creating a new BSP that inherits from powerpc/shared.

In the usual way, the BSP inherits from the shared area by using VPATH
and overrides specific files by providing its own version which is found
first on VPATH.

This works fine for C files but the semantics for headers are different:
The Makefile.ams in the shared area actually cause some of the shared
headers to be installed --> during the 'preinstall' step, the 'shared' 
headers
are installed and *not* the BSP specific ones.

Shouldn't the 'shared' area just be a mere repository for files and the
'make' process never really build anything in the 'shared' area?
The BSP would then have to explicitely mention all the files it needs/wants
and it has complete control.

How would you, Ralf, address this problem?

Thanks
-- Till