Re: [PATCH v5] arm: Add Kconfig entry to select CONFIG_DTB_FILE

[Jan Beulich <jbeulich@xxxxxxxx>]

On 11.03.2021 15:22, Michal Orzel wrote:
> Currently in order to link existing DTB into Xen image
> we need to either specify option CONFIG_DTB_FILE on the
> command line or manually add it into .config.
> Add Kconfig entry: CONFIG_DTB_FILE
> to be able to provide the path to DTB we want to embed
> into Xen image. If no path provided - the dtb will not
> be embedded.
> 
> Remove the line: AFLAGS-y += -DCONFIG_DTB_FILE=\"$(CONFIG_DTB_FILE)\"
> as it is not needed since Kconfig will define it in a header
> with all the other config options.
> 
> Make a change in the linker script from:
> _sdtb = .;
> to:
> PROVIDE(_sdtb = .);
> to avoid creation of _sdtb if there is no reference to it.
> 
> Signed-off-by: Michal Orzel <michal.orzel@xxxxxxx>

Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
albeit I think that, as suggested, ...

> --- a/xen/arch/arm/xen.lds.S
> +++ b/xen/arch/arm/xen.lds.S
> @@ -222,7 +222,7 @@ SECTIONS
>  
>  #ifdef CONFIG_DTB_FILE
>    /* Section for the device tree blob (if any). */
> -  _sdtb = .;
> +  PROVIDE(_sdtb = .);
>    .dtb : { *(.dtb) } :text
>  #endif

.. the now pointless (always true) #ifdef here should also go
away.

Jan