[U-Boot] [PATCH 0/9] EFI payload / application support

[Dennis Gilmore]

On Monday, January 04, 2016 02:54:40 PM Tom Rini wrote:
> On Mon, Jan 04, 2016 at 07:41:42PM +0100, Andreas Färber wrote:
> > Am 04.01.2016 um 19:03 schrieb Andreas Färber:
> > > Am 04.01.2016 um 17:56 schrieb Tom Rini:
> > >> Please note that with the generic distro framework U-Boot will grok
> > >> https://wiki.freedesktop.org/www/Specifications/BootLoaderSpec/ and
> > >> things Just Work.  I setup a bunch of SD cards with Debian and Fedora
> > >> over holiday so I can drop them in whatever board and boot up Linux as
> > >> a
> > >> sanity test.
We do not fully support bootloader spec in u-boot today. but I know that we 
want to one day 

> > >> I certainly can see a usecase for kicking off an EFI binary as part of
> > >> fitting into existing work-flows.  But we do already have a something
> > >> for getting rid of that particular pain-point and it's working :)
> > 
> > [snip]
> > 
> > Executive summary: https://xkcd.com/927/
> 
> Oh pretty much.  I guess the point I am driving at here is that EFI
> loading (to kick off GRUB2) needs to fit in with the framework that
> other distros have already adapted to.  Or heck, maybe you can convince
> them to switch over to this instead?  Hans or Dennis, what do you think?

not opposed to it, but it is not something that we have evaluated, I know 
debian have done a lot of work to ensure that their systems support 
extlinux.conf also. which is the same syslinux format as used by 
extlinux/syslinux/isolinux on x86, the user experience is somewhat similiar to 
that of grub on other arches.  Long term I have planed to wire up menu support 
so you get a menu to interact with rather than a list of boot options, as well 
as the ability to edit the commandline arguments. I would not say we have 
perfect support today for extlinux. so far SuSE is the only one saying no to 
what has been proposed. It was brought up on both the u-boot and linaro cross 
distro list back in 2013[1][2] with no one saying it was not a good idea.while 
there was less feedback than I would have liked it was positive.

Anyway my main question is how dtb support would work. As that really is the 
trickiest part that I can think of.  Something that is gracefully dealt with 
in the extlinux support, regardless of distro.  Going this approach to me 
feels like trying to put a Ford engine in a GM car by adding a volkswagon 
gearbox. can we make grub a u-boot application? that is not using CONFIG_API 
or does not need to have hard coded memory locations in it?  we looked at 
grub2 support years ago as we felt that it would be the way to go as it seemed 
people were standardising on it. and decided that there were too many issues 
with the implementation for it to be viable.  so we went the route of 
proposing the extlinux.conf file option. 

Dennis 


[1] https://lists.linaro.org/pipermail/cross-distro/2013-August/000439.html
[2] http://lists.denx.de/pipermail/u-boot/2013-August/160080.html