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From:   Ard Biesheuvel <ardb@kernel.org>
Date:   Tue, 3 Mar 2020 20:11:34 +0100
Message-ID: <CAKv+Gu_Xbw7SjdCvHMrDXW4o-XtM8FH4LAXPtro9cXSecVuFSA@mail.gmail.com>
Subject: Re: [PATCH 3/5] efi/x86: Add kernel preferred address to PE header
To:     Arvind Sankar <nivedita@alum.mit.edu>
Cc:     linux-efi <linux-efi@vger.kernel.org>,
        "the arch/x86 maintainers" <x86@kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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On Mon, 2 Mar 2020 at 00:05, Arvind Sankar <nivedita@alum.mit.edu> wrote:
>
> Store the kernel's link address as ImageBase in the PE header. Note that
> the PE specification requires the ImageBase to be 64k aligned. The
> preferred address should almost always satisfy that, except for 32-bit
> kernel if the configuration has been customized.
>
> Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
> ---
>  arch/x86/boot/header.S | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S
> index 4ee25e28996f..0d8d2cb28fd9 100644
> --- a/arch/x86/boot/header.S
> +++ b/arch/x86/boot/header.S
> @@ -138,10 +138,12 @@ optional_header:
>  #endif
>
>  extra_header_fields:
> +       # PE specification requires ImageBase to be 64k-aligned
> +       .set    ImageBase, (LOAD_PHYSICAL_ADDR+0xffff) & ~0xffff

Could you call this image_base please, and put some spaces around the +

>  #ifdef CONFIG_X86_32
> -       .long   0                               # ImageBase
> +       .long   ImageBase                       # ImageBase
>  #else
> -       .quad   0                               # ImageBase
> +       .quad   ImageBase                       # ImageBase
>  #endif
>         .long   0x20                            # SectionAlignment
>         .long   0x20                            # FileAlignment
> --
> 2.24.1
>