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

[Scott Wood <scottwood@freescale.com>]

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.

> > 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?

> 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.

-Scott