From mboxrd@z Thu Jan  1 00:00:00 1970
From: hpa@zytor.com (H. Peter Anvin)
Date: Wed, 16 Jul 2014 16:49:12 -0700
Subject: [PATCH v2 1/3] ACPI: ARM64 does not have a BIOS add config for
 BIOS table scan.
In-Reply-To: <3908561D78D1C84285E8C5FCA982C28F3285FB3C@ORSMSX114.amr.corp.intel.com>
References: <1404898746-6685-1-git-send-email-hanjun.guo@linaro.org>
 <1404898746-6685-2-git-send-email-hanjun.guo@linaro.org>
 <53C70CCC.2080109@zytor.com>
 <3908561D78D1C84285E8C5FCA982C28F3285FB3C@ORSMSX114.amr.corp.intel.com>
Message-ID: <53C70F78.40206@zytor.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On 07/16/2014 04:46 PM, Luck, Tony wrote:
>> +	select ACPI_LEGACY_TABLES_LOOKUP if ACPI
> 
>> This shouldn't actually be set on IA64, should it?  IA64 doesn't have
>> BIOS, either, it has EFI/UEFI, like ARM64...
> 
> Which ACPI tables are in the "LEGACY" category affected by this option?
> 

That's not what this is about... it is about how you find the root pointer.

On a BIOS system it is found by scanning low memory.  On an EFI system
it is found by querying EFI for a specific UUID.

	-hpa