Re: [PATCH 1/3] x86/boot: Initialise BSS as soon as possible

[Jan Beulich <jbeulich@xxxxxxxx>]

On 10.09.2024 18:16, Frediano Ziglio wrote:
> --- a/xen/arch/x86/boot/head.S
> +++ b/xen/arch/x86/boot/head.S
> @@ -231,6 +231,27 @@ __efi64_mb2_start:
>          /* VGA is not available on EFI platforms. */
>          movl   $0,vga_text_buffer(%rip)
>  
> +        /*
> +         * Align the stack as UEFI spec requires. Keep it aligned
> +         * before efi_multiboot2() call by pushing/popping even
> +         * numbers of items on it.
> +         */
> +        and     $~15,%rsp

You don't use the stack below, so it's not clear if/why this needs
moving. If it does, please add the missing blank after the comma
(like you nicely do everywhere else).

Apart from this there's the question on the precise placement of
the calls - see respective comment on patch 2 (which I needed to
look at first to have an opinion here).

Jan