ARM A53 and initial MMU mapping for EL0/1/2/3 ?

[Andre Przywara]

On Wed,  9 Feb 2022 14:05:57 +0100
Michael Walle <michael at walle.cc> wrote:

Hi,

> >> The problem I have is that I boot a custom SOC into u-boot and when u-boot tries
> >> to boot linux I get an error exception when u-boot calls armv8_switch_to_el2 to enter linux.  
> >
> > So that means that U-Boot runs in EL3, is that the first and only firmware
> > that you run? I think the EL3 part of U-Boot is not widely used and tested
> > beyond the very few platforms that use it.  
> 
> FWIW, the u-boot on the kontron_sl28 (which is a A72 core) is running
> in EL3. But it's a layerscape so it might be worth looking in
> arch/arm/cpu/armv8/fsl-layerscale/ if there is anything special.

Thanks Michael, that's what I meant: the generic EL3 code in
arch/arm/cpu/armv8 might depend on more platform specific code to make it
work.

Cheers,
Andre