From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1752732Ab2KXWdO (ORCPT <rfc822;w@1wt.eu>);
	Sat, 24 Nov 2012 17:33:14 -0500
Received: from terminus.zytor.com ([198.137.202.10]:43085 "EHLO mail.zytor.com"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S1752635Ab2KXWdM (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
	Sat, 24 Nov 2012 17:33:12 -0500
Message-ID: <50B14AFB.3040500@zytor.com>
Date: Sat, 24 Nov 2012 14:32:27 -0800
From: "H. Peter Anvin" <hpa@zytor.com>
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:16.0) Gecko/20121029 Thunderbird/16.0.2
MIME-Version: 1.0
To: Yinghai Lu <yinghai@kernel.org>
CC: "Eric W. Biederman" <ebiederm@xmission.com>,
        Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@elte.hu>,
        linux-kernel@vger.kernel.org, Rob Landley <rob@landley.net>,
        Matt Fleming <matt.fleming@intel.com>
Subject: Re: [PATCH v3 11/12] x86, boot: add fields to support load bzImage
 and ramdisk high
References: <1353482170-10160-1-git-send-email-yinghai@kernel.org> <1353482170-10160-12-git-send-email-yinghai@kernel.org> <50AD0CA1.8000904@zytor.com> <CAE9FiQUSjRT-r5ZE3WHVaKkUOhwFWkm9CTCv1Aa63DOsfMQMiQ@mail.gmail.com> <50AD291A.10600@zytor.com> <CAE9FiQVed0tXhbtmc_Gug0gFZ=s=j=N4B5Vr2_ZTmSj6L-65dw@mail.gmail.com> <a1ca794a-09d4-4d36-8c8c-67100cb3696e@email.android.com> <CAE9FiQXJO8uxT9Gzjv9e8XeiLzwBX7fwTFzDVy=oPfboG4L=3Q@mail.gmail.com> <CAE9FiQWeGz2TkLBrBZcoPrNABx51XK3xk58P+Zam_LRGoJdSiw@mail.gmail.com> <a8b15bf0-4e3b-4fde-9190-26890f9abf77@email.android.com> <CAE9FiQUoj9k0Tbqp8LC8Wb21_s_x8naiWX4zkX9pJG-oFnAQ9g@mail.gmail.com> <50AE70E7.6060204@zytor.com> <87haofi3d3.fsf@xmission.com> <50B104BC.90208@zytor.com> <50B124E9.400@zytor.com> <CAE9FiQWKzH+BLwak5-n2px1Yhti872o=Qte-v_8N_5X3YSJ=5A@mail.gmail.com> <50B13E53.4060003@zytor.com> <CAE9FiQWoCyuGNqHSAZU_NXwjci3BJZQmmAUnWPn_pKCzEt8h7g@mail.gmail.com>
In-Reply-To: <CAE9FiQWoCyuGNqHSAZU_NXwjci3BJZQmmAUnWPn_pKCzEt8h7g@mail.gmail.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On 11/24/2012 02:18 PM, Yinghai Lu wrote:
>>
>> Careful... consider the people who use a kexec-based solution as
>> bootloaders.
>
> yes, those may not update kexec in the flash...
>
> then, may need to use another bit in xloadflags to tell new kernel if
> need to check ext_...
>
> Field name:     xloadflags
> Type:           modify (obligatory)
> Offset/size:    0x236/2
> Protocol:       2.12+
>
>    This field is a bitmask.
>
>    Bit 0 (read): CAN_BE_LOADED_ABOVE_4G
>          - If 1, kernel/boot_params/cmdline/ramdisk can be above 4g,
>                  set by kernel.
>
>    Bit 1 (write): LOADED_ABOVE_4G
>          - If 1, kernel/boot_params/cmdline/ramdisk is loaded above 4g,
>                  set by bootloader, and kernel will check ext_ramdisk_image,
>                  ext_ramdisk_size and ext_cmd_line_ptr.
>

Well, that solves the problem for *this specific instance* but I fear 
therein lies madness in the general case.

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.