[U-Boot] [PATCH] fdt: Add warning about CONFIG_OF_EMBED

[Simon Goldschmidt]

Am 05.12.2018 um 14:57 schrieb Simon Glass:
> This option has crept into use with some boards. Add a warning to try to
> prevent this.
> 
> As an example:
>     https://lists.denx.de/pipermail/u-boot/2017-September/304966.html

We have just discussed this in another thread. There seem to be ~109 
defconfigs in the tree that enable OF_EMBED.

I doubt all of them do this for fun, so we might want to collect the 
reasons they do so. I do know two:

- socfpga_stratix10_defconfig needs this to get a correct u-boot-spl.hex
- I would need it to ensure in SPL, the DTB is in one block with the 
other readonly parts. Without OF_EMBED, we have '.text', '.bss', DT.

Regards,
Simon

> 
> Signed-off-by: Simon Glass <sjg at chromium.org>
> ---
> 
>   Makefile | 8 ++++++++
>   1 file changed, 8 insertions(+)
> 
> diff --git a/Makefile b/Makefile
> index 0d11ff97971..05896598fe3 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -947,6 +947,14 @@ ifeq ($(CONFIG_LIBATA)$(CONFIG_DM_SCSI)$(CONFIG_MVSATA_IDE),y)
>   	@echo "Failure to update by the deadline may result in board removal."
>   	@echo "See doc/driver-model/MIGRATION.txt for more info."
>   	@echo "===================================================="
> +endif
> +ifeq ($(CONFIG_OF_EMBED),y)
> +	@echo "===================== WARNING ======================"
> +	@echo "CONFIG_OF_EMBED is enabled. This option should only"
> +	@echo "be used for debugging purposes. Please use"
> +	@echo "CONFIG_OF_SEPARATE for boards in mainline."
> +	@echo "See doc/README.fdt-control for more info."
> +	@echo "===================================================="
>   endif
>   	@# Check that this build does not use CONFIG options that we do not
>   	@# know about unless they are in Kconfig. All the existing CONFIG
>