Re: [RFC PATCH 0/1] Add driver for bootstage stash

Francesco Valla <[email protected]> Fri, 23 May 2025 22:06:31 +0200
Newsgroups org.kernel.vger.linux-embedded
Message-ID <[email protected]>
Hi Geert,

On Friday, 23 May 2025 at 09:04:48 Geert Uytterhoeven <[email protected]> wrote:
> >
> > At U-Boot side, following configuration shall then be set:
> >
> >     CONFIG_BOOTSTAGE=y
> >     CONFIG_BOOTSTAGE_STASH_ADDR=0xa4300000
> >     CONFIG_BOOTSTAGE_STASH_SIZE=0x1000
> 
> I think this can be simplified further, using either of these two options:
>   1. If the bootstage@a4300000 node would already be present in the
>      DTB used by U-Boot, the two CONFIG_BOOTSTAGE_STASH_*
>      options would no longer be needed.
>   2. U-Boot could add the bootstage@a4300000 to the DTB that is
>      passed to the kernel, just like it already adds/updates the memory
>      nodes.
> 

The second option is probably the best one, as it aligns with other
similar usecases (e.g.: OP-TEE node [1]). Once it has been determined that
this driver is the right approach, it should be pretty simple to do.

[1] https://elixir.bootlin.com/u-boot/v2025.04/source/lib/optee/optee.c#L112

> Gr{oetje,eeting}s,
> 
>                         Geert
> 
> 

Regards,

Francesco