[U-Boot] [PATCH 3/4] sunxi: Add default partition scheme

[Emmanuel Vadot]

On Mon, 20 Nov 2017 10:24:08 +0100
Maxime Ripard <maxime.ripard at free-electrons.com> wrote:

> Hi,
> 
> On Fri, Nov 17, 2017 at 03:20:03PM +0100, Alexander Graf wrote:
> > 
> > 
> > On 17.11.17 14:04, Maxime Ripard wrote:
> > > On Fri, Nov 17, 2017 at 12:21:49PM +0000, Andre Przywara wrote:
> > >> Hi,
> > >>
> > >> On 17/11/17 08:27, Maxime Ripard wrote:
> > >>>
> > >>> I guess I also have a side question here. How do the installers deal
> > >>> with the ESP partition? Would they create a new filesystem on it no
> > >>> matter what, or are they a bit smarter than that?
> > >>
> > >> I would expect any installer to not mess with the ESP. After all the ESP
> > >> belongs to the firmware, and multiboot (both multiple Linux versions as
> > >> well as other OSes like Windows or BSD) is one main feature of the ESP.
> > >>
> > >> The only exception might be if the ESP is not formatted.
> > >>
> > >>> My actual question being what will happen if one stores the U-Boot
> > >>> environment on that partition, and then runs an installer? Would the
> > >>> environment be gone?
> > >>
> > >> I would say that the ESP is a perfect place for the environment. It's
> > >> FAT and it belongs to firmware, so OSes are just expected to *add* their
> > >> bootloaders, without touching any other file on it.
> > > 
> > > Ok, perfect then, thanks!
> > 
> > Please make sure to
> > 
> >   a) Format it as FAT and
> 
> That might be the toughest part :)
> 
> AFAIK, u-boot is not able to format any filesystem. We could just
> flash a raw FAT filesystem though, but looking into it might help for
> the environment discussion.

 Also note that if we go to 16MB for the size you need to tweek
clusters and other properties for FAT32 as using the default ones will
not work (the minimal size is ~35MB iirc).

> >   b) Mark it with the ESP GUID
> 
> That's easy thouh. What is this GUID?
> 
> Thanks!
> Maxime
> 
> -- 
> Maxime Ripard, Free Electrons
> Embedded Linux and Kernel engineering
> http://free-electrons.com


-- 
Emmanuel Vadot <manu at bidouilliste.com> <manu at freebsd.org>