[U-Boot] [PATCH 1/4] common: imx: Implement generic u-boot.nand target

[Marek Vasut <marex@denx.de>]

Dear Scott Wood,

> On 02/25/2013 03:10:35 PM, Marek Vasut wrote:
> > Dear Scott Wood,
> > 
> > > On 02/25/2013 12:19:54 PM, Marek Vasut wrote:
> > > > +$(obj)u-boot.nand: $(obj)u-boot.bin depend
> > > > +		if [ "X$(CONFIG_NAND_TRG_PATH)X" = "XX" ] ;
> > > > then		\
> > > > +			echo "This CPU does not support u-boot.nand
> > > > target!" ;	\
> > > > +			exit 1
> > > > ;						\
> > > > +		fi
> > > > +		$(MAKE) -C $(CONFIG_NAND_TRG_PATH) $(obj)u-boot.nand
> > > 
> > > We already have CONFIG_SPL_TARGET.  Why do we need a new mechanism
> > > specific to NAND, with ifdefs in the main Makefile?
> > 
> > This board doesn't use SPL at all.
> 
> So maybe we need a more general (but optional) CONFIG_BUILD_TARGET.

Can you elaborate?

> > > If we do have something specific to NAND, it should be
> > 
> > u-boot-nand.bin
> > 
> > > to match what nand_spl produced, and it should just be a generic
> > 
> > rule
> > 
> > > that links to what CONFIG_SPL_TARGET produced, if the right CONFIG
> > > symbol is set by the board config to say that this is a NAND SPL.
> > 
> > Or
> > 
> > > is someone going to say that they want to generate multiple
> > 
> > different
> > 
> > > SPL images from the same build? :-P
> > 
> > I'd like to generate a bootable NAND image on mx53 and on mx23/28,
> 
>  From the same build, or just in general?

What do you mean by 'from the same build' ? From a build for the particular 
board running the SOC=mxs .

> > thus I need generic target. And I need it flexible enough, since on
> > mx23/28 it munges u-
> > boot.sb into the resulting image while on mx53 it munges u-boot.imx
> > into the
> > resulting image.
> 
> So each one would set the appropriate CONFIG_BUILD_TARGET for whatever
> needs to get built, and then something like CONFIG_NAND_IMAGE could
> hold the image name that should be linked to produce a standard
> u-boot-nand.bin output.

Yea, sounds reasonable. But why call it CONFIG_ , it can't be stored in the 
board.h files, it has to be somewhere in the Makefile hierarchy.

> -Scott

Best regards,
Marek Vasut