Re: [PATCH for-4.19] docs/arm: Document where Xen should be loaded in memory

[Michal Orzel <michal.orzel@xxxxxxx>]

Hi Julien,

On 24/10/2023 12:09, Julien Grall wrote:
> 
> 
> From: Julien Grall <jgrall@xxxxxxxxxx>
> 
> In commit 9d267c049d92 ("xen/arm64: Rework the memory layout"),
> we decided to require Xen to be loaded below 5 TiB to simplify
s/5/2

> the logic to enable the MMU. The limit was decided based on
> how known platform boot plus some slack.
> 
> We had a recent report that this is not sufficient on the AVA
> platform with a old firmware [1]. But the restriction is not
> going to change in Xen 4.18. So document the limit clearly
> in docs/misc/arm/booting.txt
> 
> Signed-off-by: Julien Grall <jgrall@xxxxxxxxxx>
> 
> ----
one less '-'

> 
> I couldn't find a nice way to document it in SUPPORT.md. So I decided
> to only document the restrict in docs/misc/arm/booting.txt for now.
> 
> I also couldn't find any way from GRUB/UEFI (I didn't look much) to
> specify the loading address.
> ---
>  docs/misc/arm/booting.txt | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/docs/misc/arm/booting.txt b/docs/misc/arm/booting.txt
> index 02f7bb65ec6d..c6bdeafe5e5b 100644
> --- a/docs/misc/arm/booting.txt
> +++ b/docs/misc/arm/booting.txt
> @@ -21,6 +21,10 @@ The exceptions to this on 32-bit ARM are as follows:
>   zImage protocol should still be used and not the stricter "raw
>   (non-zImage)" protocol described in arm/Booting.
> 
> +The exceptions to this on 64-bit ARM are as follows:
> +
> + Xen binary should be loaded in memory below 2 TiB.
> +
>  There are no exception on 64-bit ARM.
This sentence needs to be dropped then.

With that:
Reviewed-by: Michal Orzel <michal.orzel@xxxxxxx>

~Michal