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

[Scott Wood <scottwood@freescale.com>]

On 02/25/2013 12:19:54 PM, Marek Vasut wrote:
> Implement u-boot.nand target that can be reused with a small amount of
> churn across all CPU models. The idea is to delegate the u-boot.nand  
> target
> out of the main Makefile and into the CPU's Makefile (very similar to  
> what
> u-boot.imx does now). The main Makefile shall only contain path to  
> which the
> u-boot.nand target is delegated. Hopefully this will not produce too  
> much
> bloat in the main Makefile.
> 
> To demonstrate this implementation, add u-boot.nand target for i.MX53.
> 
> Signed-off-by: Marek Vasut <marex@denx.de>
> Cc: Beno?t Th?baudeau <benoit.thebaudeau@advansee.com>
> Cc: Fabio Estevam <fabio.estevam@freescale.com>
> Cc: Stefano Babic <sbabic@denx.de>
> ---
>  Makefile                     |   18 ++++++++++++++++++
>  arch/arm/imx-common/Makefile |    6 ++++++
>  2 files changed, 24 insertions(+)
> 
> diff --git a/Makefile b/Makefile
> index 41054b7..8b1010a 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -470,6 +470,23 @@ $(obj)u-boot.img:	$(obj)u-boot.bin
>  $(obj)u-boot.imx: $(obj)u-boot.bin depend
>  		$(MAKE) -C $(SRCTREE)/arch/arm/imx-common  
> $(obj)u-boot.imx
> 
> +#
> +# Generic u-boot.nand target.
> +#
> +# Every CPU that needs u-boot.nand must add a path to an  
> implementation of
> +# the actual u-boot.nand generator below.
> +#
> +ifdef CONFIG_MX53
> +CONFIG_NAND_TRG_PATH := $(SRCTREE)/arch/arm/imx-common
> +endif
> +
> +$(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?

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

-Scott