Setting up boot chain ACPI on ARM with STM32MPU

[Moritz Fischer]

Hi,

On Wed, Nov 29, 2023 at 11:28 AM Simon Glass <sjg at chromium.org> wrote:
>
> +Heinrich Schuchardt
>
> Hi,
>
> On Wed, 29 Nov 2023 at 08:29, Ba Gia Bao Phan
> <phanbagiabao2001 at gmail.com> wrote:
> >
> > Hello everyone,
> >
> > I am a trainee at STMicroelectronics France. I am working on a project "Setting up a boot chain ACPI" for STM32MPU, which is based on ARM Cortex-A . The objective of my project is to add a way of booting (with ACPI) besides Device Tree available on STM32MPU.
> >
> > I found that ACPI was enabled on some x86 platforms but I don't know whether it was set up on ARM or not. I found a PATCH that discussed Enabling ACPI booting on ARM with Raspberry Pi 4 but I don't know if it functioned or not. Did anyone here succeed in setting up ACPI on ARM by U-boot?
>
> Sort-of...the refactoring to allow ACPI tables on ARM is completed,
> but I don't think any U-Boot board uses this.
>
> >
> > What are the differences between x86 and ARM platforms when enabling ACPI? The architecture of my board STM32PMU is ARM so can I apply the technique used on platform x86 for my board?
>
> Firstly I wonder why you want ACPI?

I think STM32MPU is as good as any platform to get the pipe flushed
with enabling ACPI on ARM platforms.

Overall I think it's a worthwhile endeavour to get this sorted for at
least one ARM platform as a starting point.

> Secondly, if you have the tables somewhere it should be easy enough to
> build them, building on the series you pointed to. Heinrich is
> interested in this, I think. I can help with advice. I have been
> toying with going back to that rpi series but have not done so yet.

I've started to mess around with this over the holidays. Feel free to
CC me on future work in that direction.

- Moritz