[U-Boot] [PATCH v8 0/3] armv8: Support loading 32-bit OS in AArch32 execution state

[Alison Wang]

> On 10 November 2016 at 02:49, Alison Wang <b18965 at freescale.com> wrote:
> > This series is to support loading a 32-bit OS, the execution state
> will change from AArch64 to AArch32 when jumping to kernel. The
> architecture information will be got through checking FIT image, then
> U-Boot will load 32-bit OS or 64-bit OS automatically.
> >
> > Spin-table method is used for secondary cores to load 32-bit OS.
> > The architecture information will be got through checking FIT image
> and saved in the os_arch element of spin-table, then the secondary
> cores will check os_arch and jump to 32-bit OS or 64-bit OS
> automatically.
> >
> > PSCI method can also be used for secondary cores to load 32-bit OS.
> > As PSCI and secure monitor firmware framework are enabled, loading
> 32-bit OS is supported in such case. The default target exception level
> returned to U-Boot is EL2, so the corresponding work to switch to
> AArch32 EL2 and jump to 32-bit OS are done in U-Boot and secure
> firmware together.
> >
> > ---------------------------------------
> > Changes in v8:
> > - Fix the issue when U-Boot is running in EL2 or EL1.
> 
> Thanks for sticking with this.  Great news: it works for my setup.
> 
> I tested booting an arm64 kernel on FVP Foundation and AEMv8 modes and
> on Juno R0, R1 and R2.  I also tested and Versatile Express TC2 can
> still load it's Aarch32 kernel.
> 
> I didn't test running an Aarch32 kernel or any of the new functionality
> on my ARMv8 platforms.
> 
> But I checked and the patches are bisect-able on my ARMv8 platforms.
> 
> Tested-by: Ryan Harkin <ryan.harkin at linaro.org>
> 
[Alison Wang] Thanks for your verification.


Best Regards,
Alison Wang