[U-Boot] What if ATF can be part of U-Boot source, like SPL?

[Michael Nazzareno Trimarchi]

On Sun, Jun 30, 2019 at 4:03 PM Marek Vasut <marek.vasut at gmail.com> wrote:
>
> On 6/30/19 3:57 PM, Tom Rini wrote:
> > On Sat, Jun 29, 2019 at 08:32:00PM +0530, Jagan Teki wrote:
> >
> >> In terms of code maintenance and development feasibility it is always
> >> a better approach to have out-of-tree code or binary to be part of
> >> in-house source tree.
> >>
> >> This is what exactly it was done for SPL, if I'm not wrong. So can we
> >> do the same thing for ATF on ARM64 SoCs?
> >>
> >> We are using ATF (on Allwinner) to switch EL3 to EL2 for start loading
> >> U-Boot proper and minimal PSCI, PMIC initialization. So assuming the
> >> functionality of ATF (like here) is limited so the code it require can
> >> be limited too, so why can't this code to be part of U-Boot tree?
> >>
> >> This would ultimately avoid out-off-tree ATF builds with associated
> >> variable exporting during u-boot builds.
> >>
> >> More over this idea would also help to design a single-step bootloader
> >> where it can't depends on out-of-tree sources.
> >>
> >> Code sync from ATF source to U-Boot can be possible in-terms licensing
> >> point-of-view since ATF licensed under BSD-3-Clause.
> >>
> >> I'm thinking this can be a worth-idea to look at it and I'm sure It
> >> may require some hard changes and other things to consider but just
> >> posted to understand how hard or feasible or meaningful it is?
> >>
> >> Feel free for any comments?
> >
> > Given that we have "TPL" and "SPL", my "pie in the sky" wish would be
> > for the ability to build different U-Boots to fill the different aspects
> > of the aarch64 boot flow.
> >
> > That said, patches that would in turn allow for users to locally add ATF
> > as a git submodule and then build that, if cleanly done, could be
> > interesting.  But must not impact the normal build flow.
>
> So can we also add Linux as a submodule ? And glibc ? Maybe busybox too ?
>

If we continue to import  Linux subsystem, we don't need to import
Linux ;). We need
a good rsync

Michael

> --
> Best regards,
> Marek Vasut