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Date: Thu, 21 Jul 2016 11:14:11 +0200
From: Ingo Molnar <mingo@kernel.org>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@kernel.org>, x86@kernel.org,
        Mario Limonciello <mario_limonciello@dell.com>,
        Matthew Garrett <mjg59@srcf.ucam.org>, linux-kernel@vger.kernel.org,
        Kees Cook <keescook@chromium.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Andrew Morton <akpm@linux-foundation.org>,
        Peter Zijlstra <a.p.zijlstra@chello.nl>
Subject: Re: [PATCH] x86/boot: Reorganize and clean up the BIOS area
 reservation code
Message-ID: <20160721091411.GB22986@gmail.com>
References: <7c190e9b3376002014fb99234ed5e5c64df86322.1469064662.git.luto@kernel.org>
 <20160721081438.GA26531@gmail.com>
 <92DA2E2A-BCD9-4198-A983-395A06388688@zytor.com>
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* H. Peter Anvin <hpa@zytor.com> wrote:

> We already reserve the first megabyte by default.  There is something really bizarre about this; the bug report simply doesn't seem to make any sense.

Btw., are you sure about this? We do reserve the first 64KB:

config X86_RESERVE_LOW
        int "Amount of low memory, in kilobytes, to reserve for the BIOS"
        default 64
        range 4 640
        ---help---
          Specify the amount of low memory to reserve for the BIOS.

But I cannot find the place that allocates the first 1MB.

Thanks,

	Ingo