Re: [PATCH v2] x86/boot: Use EFI setup data if provided

From: Borislav Petkov
Date: Fri Mar 29 2019 - 04:39:29 EST


On Fri, Mar 29, 2019 at 03:05:52AM +0000, Junichi Nomura wrote:
> > You don't need that variable and can return "table" or 0 after the endif
> > below.
>
> I could do that but it will slightly change the current logic.
>
> Existing code does this:
>
> if (!(efi_guidcmp(guid, ACPI_TABLE_GUID)))
> rsdp_addr = table;
> else if (!(efi_guidcmp(guid, ACPI_20_TABLE_GUID)))
> return table;
>
> I thought it was to return the table for ACPI_20_TABLE_GUID
> if both tables exist. If we remove rsdp_addr, the code will be:
>
> if (!(efi_guidcmp(guid, ACPI_TABLE_GUID)))
> return table;
> else if (!(efi_guidcmp(guid, ACPI_20_TABLE_GUID)))
> return table;
>
> So if there are 2 tables, we return the one that comes first.
> Is it ok?

That's a good question.

Chao, what was the intention there, ACPI_20_TABLE_GUID is the preferred
table to return? If so, why?

--
Regards/Gruss,
Boris.

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