Re: [boot-wrapper v4 0/4] Add Armv8-R AArch64 support

[Mark Rutland <mark.rutland@arm.com>]

Hi Luca,

Sorry for the long delay on this; I've picked up patches 1-3 and pushed
those out, but I have some concerns with the Xen support in patch 4
(which I'll comment on there).

Mark.

On Thu, Oct 17, 2024 at 10:55:16AM +0100, Luca Fancellu wrote:
> Currently, we cannot boot Linux with boot-wrapper on Armv8-R AArch64:
> 1. The Armv8-R AArch64 profile does not support the EL3.
> 2. The Armv8-R AArch64 EL2 only supports a PMSA, which Linux does not
> support. So it's necessary to drop into EL1 before entering the kernel.
> 3. There is no EL2 booting code for Armv8-R AArch64 and no
> configuration for dropping to EL1 in boot-wrapper.
> 
> These patches enable boot-wrapper booting Linux with Armv8-R AArch64.
> 
> This work took inspiration from a serie already present upstream [1].
> 
> [1] https://patchwork.kernel.org/project/linux-arm-kernel/cover/20210525062509.201464-1-jaxson.han@arm.com/
> 
> Changes from v3:
> - rebase on current master
> - detailed changes on each patch
> Changes from v2:
>  - Now this work is based on this serie:
>    https://patchwork.kernel.org/project/linux-arm-kernel/cover/20240729161501.1806271-1-mark.rutland@arm.com/
>    Given the major rework, dropped every R-by.
> Changes from v1:
>  - Dropped patch 4 regarding GIC changes, it's not needed anymore.
> 
> Luca Fancellu (4):
>   Introduce --with-bw-arch for boot-wrapper compile arch
>   aarch64: Enable Armv8-R EL2 boot
>   aarch64: Implement PSCI for Armv8-R
>   aarch64: Start Xen on Armv8-R at EL2
> 
>  Makefile.am                    |  7 ++-
>  arch/aarch64/boot.S            |  5 ++
>  arch/aarch64/include/asm/cpu.h | 24 ++++++++++
>  arch/aarch64/init.c            | 83 ++++++++++++++++++++++++++++++++--
>  configure.ac                   | 20 ++++++--
>  5 files changed, 130 insertions(+), 9 deletions(-)
> 
> -- 
> 2.34.1
>