U-Boot as ARM Coreboot Payload (for Chromebook Duet)

[Dennis Gilmore]

Simon,

Is there a way to replace the firmware on those boards with u-boot?  I
have a Tegra, a rockchip, and a pair of Samsung Exynos based
Chromebooks that are end of life for ChromeOS but are still quite
useful hardware platforms if there was a way to replace entirely the
bootloader with u-boot I could have hardware running supported
operating systems.

Dennis

On Sun, Aug 2, 2020 at 10:00 PM Simon Glass <sjg at chromium.org> wrote:
>
> Hi Matthew,
>
> On Sun, 2 Aug 2020 at 20:17, Matthew Grochowalski <matt at gwalski.com> wrote:
> >
> > Hello,
> >
> > Reading https://chromium.googlesource.com/chromiumos/docs/+/master/developer_mode.md,
> > it appears U-Boot should work as an alternate firmware on new ARM
> > Chromebooks.
> >
> > Trying on my Duet (Kukui/Krane), this doesn't work. Looking at the
> > RW_LEGACY contents, there's basically nothing there from the factory.
> >
> > I tried "make coreboot_defconfig" from u-boot master, but it looks
> > like this is x86 only.
> >
> > Any way to get this working on ARM(64)?
>
> I think this is Mediatek and U-Boot doesn't have support for that
> particular MT part, at least in mainline. I suspect it will happen at
> some point.
>
> The altfw U-Boot feature works on x86 Chromebooks only, at present.
> That said, most tegra and rockchip Chromebooks support U-Boot running
> 'bare-metal'.
>
> Regards,
> Simon