Re: [PATCH 3/3] x86/boot: Rewrite EFI start part in C

[Jan Beulich <jbeulich@xxxxxxxx>]

On 24.09.2024 17:21, Frediano Ziglio wrote:
> On Mon, Sep 23, 2024 at 3:26 PM Jan Beulich <jbeulich@xxxxxxxx> wrote:
>>
> 
> ... omissis ...
> 
>>
>>>>> --- a/xen/arch/x86/efi/stub.c
>>>>> +++ b/xen/arch/x86/efi/stub.c
>>>>> @@ -17,7 +17,8 @@
>>>>>   */
>>>>>
>>>>>  void __init noreturn efi_multiboot2(EFI_HANDLE ImageHandle,
>>>>> -                                    EFI_SYSTEM_TABLE *SystemTable)
>>>>> +                                    EFI_SYSTEM_TABLE *SystemTable,
>>>>> +                                    const char *cmdline)
>>>>>  {
>>>>>      static const CHAR16 __initconst err[] =
>>>>>          L"Xen does not have EFI code build in!\r\nSystem halted!\r\n";
>>>>
>>>> This, if not a separate change, wants mentioning in the description.
>>>> It's a related observation that this wasn't properly updated, but
>>>> nothing that necessarily needs doing here. Question is whether the
>>>> declaration of the function wouldn't better go into a header now in
>>>> the first place.
>>>
>>> I had the same though about a header. But currently there's no such
>>> header, I mean it should be able to be included by both stub.c and
>>> efi-boot.h which are both x86 only code so it should go in
>>> xen/arch/x86/ I suppose. Suggestions? Maybe a different solution would
>>> be to have a xen/arch/x86/efi/efi-boot-stub.h instead of
>>> xen/arch/x86/efi/stub.c ?
>>
>> It's not quite the right place, but maybe (ab)using asm/efibind.h would
>> be slightly better than introducing asm/efi.h just for a single decl?
>>
>> Jan
> 
> Okay, I found the comment on the header to place the declaration.
> 
> Kind of works... but the headers are very crazily depending on each
> other, the header change is
> 
> diff --git a/xen/arch/x86/include/asm/efibind.h
> b/xen/arch/x86/include/asm/efibind.h
> index bce02f3707..1fa5522a0d 100644
> --- a/xen/arch/x86/include/asm/efibind.h
> +++ b/xen/arch/x86/include/asm/efibind.h
> @@ -1,2 +1,13 @@
> #include <xen/types.h>
> +#include <xen/init.h>
> #include <asm/x86_64/efibind.h>
> +#include <efi/efidef.h>
> +#include <efi/eficapsule.h>
> +#include <efi/eficon.h>
> +#include <efi/efidevp.h>
> +#include <efi/efiapi.h>
> +
> +void __init efi_multiboot2(EFI_HANDLE ImageHandle,
> +                           EFI_SYSTEM_TABLE *SystemTable,
> +                           const char *cmdline);
> +
> 
> How does it sound ?

Hmm, no, not good at all. All these #include-s are against the purpose
of the header. We'll need asm/efi.h then, I think.

As an aside - you don't need xen/init.h here, as declarations shouldn't
have __init attributes.

Jan