[U-Boot] [RFC PATCH 3/4] Add new folder and build system for SPL

[Wolfgang Denk]

Dear Aneesh V,

In message <4E16EAE9.5070505 at ti.com> you wrote:
> 
> >> +# create 'spl/obj' within OBJTREE for spl
> >> +OBJTREE := $(OBJTREE)/spl/obj

This is the part I dislike: we redefine variables and lose track of
their original values.

> >> +# We want the final binaries in this directory
> >> +obj	:= $(obj)../
> First of all, this was really intended to be:
> 
> +obj	:= $(obj)../../

Now we have already two levels oif such redefinitions, one going down
and the other going up.

This is, well, confusing.

I think, we should remember the original value of $(OBJTREE), so we
can use it here where we need it.

> > I don't really like these "../" parts.  Can we please try to omit
> > these?  We can use $(TOPDIR) and/or $(OBJTREE) instead to express the
> > path names, can't we?
> 
> Please note that even if we use $(OBJTREE), to achieve the above, we
> will need:
> 
> +obj	:= $(OBJTREE)/../
> 
> Please note that $(OBJTREE) needs to be updated before including
> config.mk while $(obj) needs to be updated after it.

Well, we can of course:

- use a different name instead of OBJTREE everywhere, and leave
  OBJTREE as reference to the origonal value for global use,  or
- introduce a new variable that stores the original setting of OBJTREE
  so we can refer to this later

> I used BUILD_DIR/spl/obj as OBJTREE to avoid this problem.

I understand what you are doing, and I agree with it.  I just dislike
the tiny implementation detaild of using relative chnages up and down
in the directory structure.  I would rather be able to use absolute
directory names (which are way easier to verify for debugging, etc.).

Best regards,

Wolfgang Denk

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