From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 12462C432C2 for ; Thu, 26 Sep 2019 07:55:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E4A672146E for ; Thu, 26 Sep 2019 07:55:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727218AbfIZHzi (ORCPT ); Thu, 26 Sep 2019 03:55:38 -0400 Received: from mail.cn.fujitsu.com ([183.91.158.132]:14739 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726492AbfIZHzh (ORCPT ); Thu, 26 Sep 2019 03:55:37 -0400 X-IronPort-AV: E=Sophos;i="5.64,551,1559491200"; d="scan'208";a="76052700" Received: from unknown (HELO cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 26 Sep 2019 15:55:35 +0800 Received: from G08CNEXCHPEKD01.g08.fujitsu.local (unknown [10.167.33.80]) by cn.fujitsu.com (Postfix) with ESMTP id 696714CE14F4; Thu, 26 Sep 2019 15:55:37 +0800 (CST) Received: from [10.167.226.60] (10.167.226.60) by G08CNEXCHPEKD01.g08.fujitsu.local (10.167.33.89) with Microsoft SMTP Server (TLS) id 14.3.439.0; Thu, 26 Sep 2019 15:55:46 +0800 Subject: Re: [RFC PATCH] x86/doc/boot_protocol: Correct the description of "reloc" To: Ingo Molnar CC: , , , , , , , References: <20190926042116.17929-1-caoj.fnst@cn.fujitsu.com> <20190926060139.GA100481@gmail.com> From: Cao jin Message-ID: Date: Thu, 26 Sep 2019 15:55:51 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190926060139.GA100481@gmail.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.167.226.60] X-yoursite-MailScanner-ID: 696714CE14F4.A8058 X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: caoj.fnst@cn.fujitsu.com Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 9/26/19 2:01 PM, Ingo Molnar wrote: > * Cao jin wrote: > >> The fields marked with (reloc) actually are not dedicated for writing, >> but communicating info for relocatable kernel with boot loaders. For >> example: >> >> ============ ============ >> Field name: pref_address >> Type: read (reloc) >> Offset/size: 0x258/8 >> Protocol: 2.10+ >> ============ ============ >> >> ============ ======================== >> Field name: code32_start >> Type: modify (optional, reloc) >> Offset/size: 0x214/4 >> Protocol: 2.00+ >> ============ ======================== >> >> Signed-off-by: Cao jin >> --- >> Unless I have incorrect non-native understanding for "fill in", I think >> this is inaccurate. >> >> Documentation/x86/boot.rst | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/Documentation/x86/boot.rst b/Documentation/x86/boot.rst >> index 08a2f100c0e6..a611bf04492d 100644 >> --- a/Documentation/x86/boot.rst >> +++ b/Documentation/x86/boot.rst >> @@ -243,7 +243,7 @@ bootloader ("modify"). >> >> All general purpose boot loaders should write the fields marked >> (obligatory). Boot loaders who want to load the kernel at a >> -nonstandard address should fill in the fields marked (reloc); other >> +nonstandard address should consult with the fields marked (reloc); other >> boot loaders can ignore those fields. >> >> The byte order of all fields is littleendian (this is x86, after all.) > > Well, this documentation is written from the point of view of a > *bootloader*, not the kernel. So the 'fill in' says that the bootloader > should write those fields - which is correct, right? > Take pref_address or relocatable_kernel for example, they have type: read (reloc), does boot loader need to write them? I don't see grub does this at least. -- Sincerely, Cao jin