[U-Boot] problem building next on P2020DS_36BIT

[Scott Wood <scottwood@freescale.com>]

Kumar Gala wrote:
> Scott,
> 
> This appears to be related to .depend generation and the patch that seems to cause the issue is:
> 
> Author: Scott Wood <scottwood@freescale.com>
> Date:   Wed Nov 4 18:41:41 2009 -0600
> 
>     makefiles: fixes for building build tools
>     
>     Currently, some of the tools instead set CC to be HOSTCC in order to re-use
>     some pattern rules -- but this fails when the user overrides CC on the make
>     command line.  Also, the HOSTCFLAGS in tools/Makefile are currently not
>     being used because config.mk overwrites them.
> 
> It looks like for some reason we aren't getting the EXTRA_CFLAGS in drivers/bios_emulator/Makefile aren't getting picked up in the .depend generation.

EXTRA_CFLAGS is not part of the u-boot build system.  CFLAGS is, but it 
is not used in dependency generation.

Prior to that change, HOSTCFLAGS was being used inappropriately in 
generating target dependencies.  If you change the HOSTCFLAGS reference 
in drivers/bios_emulator/Makefile to CPPFLAGS, it works.

Unfortunately, that makefile still has to update CFLAGS as well, because 
it's too late at that point for changes to CPPFLAGS to propagate to CFLAGS.

-Scott