From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from list by lists.gnu.org with archive (Exim 4.71) id 1cA0p8-0008U1-CF for mharc-grub-devel@gnu.org; Thu, 24 Nov 2016 15:40:50 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33810) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cA0p5-0008Rz-SW for grub-devel@gnu.org; Thu, 24 Nov 2016 15:40:48 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cA0p1-000221-Qc for grub-devel@gnu.org; Thu, 24 Nov 2016 15:40:47 -0500 Received: from userp1040.oracle.com ([156.151.31.81]:30534) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cA0p1-00021F-ES for grub-devel@gnu.org; Thu, 24 Nov 2016 15:40:43 -0500 Received: from aserv0021.oracle.com (aserv0021.oracle.com [141.146.126.233]) by userp1040.oracle.com (Sentrion-MTA-4.3.2/Sentrion-MTA-4.3.2) with ESMTP id uAOKebpG012919 (version=TLSv1 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Thu, 24 Nov 2016 20:40:37 GMT Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by aserv0021.oracle.com (8.13.8/8.14.4) with ESMTP id uAOKeaVY000490 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Thu, 24 Nov 2016 20:40:37 GMT Received: from abhmp0019.oracle.com (abhmp0019.oracle.com [141.146.116.25]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id uAOKeaeL025465; Thu, 24 Nov 2016 20:40:36 GMT Received: from olila.local.net-space.pl (/10.175.249.101) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 24 Nov 2016 12:40:36 -0800 From: Daniel Kiper To: grub-devel@gnu.org, xen-devel@lists.xenproject.org Cc: andrew.cooper3@citrix.com, arvidjaar@gmail.com, eric.snowberg@oracle.com, jgross@suse.com, konrad.wilk@oracle.com, phcoder@gmail.com, seth.goldberg@oracle.com Subject: [MULTIBOOT2 DOC PATCH v2 03/11] multiboot2: Clarify meaning of information request header tag Date: Thu, 24 Nov 2016 21:40:02 +0100 Message-Id: <1480020010-18421-4-git-send-email-daniel.kiper@oracle.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1480020010-18421-1-git-send-email-daniel.kiper@oracle.com> References: <1480020010-18421-1-git-send-email-daniel.kiper@oracle.com> X-Source-IP: aserv0021.oracle.com [141.146.126.233] X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.4.x-2.6.x [generic] [fuzzy] X-Received-From: 156.151.31.81 X-BeenThere: grub-devel@gnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: The development of GNU GRUB List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 24 Nov 2016 20:40:49 -0000 Signed-off-by: Daniel Kiper --- v2 - suggestions/fixes: - rephrase some sentences (suggested by Andrew Cooper), - add missing the articles (suggested by Andrew Cooper). --- doc/multiboot.texi | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/doc/multiboot.texi b/doc/multiboot.texi index c438b38..771aeab 100644 --- a/doc/multiboot.texi +++ b/doc/multiboot.texi @@ -443,15 +443,19 @@ u32[n] | mbi_tag_types | @end group @end example -@samp{mbi_tag_types} is an array of u32 each one representing an information -request -If this tag is present and @samp{optional} is set to @samp{0} information -conveyed by requested tag types must be present. If bootloader is unable -to supply this information it must fail with an error +@samp{mbi_tag_types} is an array of u32's, each one representing an information request. -Note: it doesn't garantee that any tags of type @samp{mbi_tag_types} will -actually be present. E.g. on a videoless system even if you requested tag -@samp{8} no tags of type @samp{8} will be present in mbi. +If this tag is present and @samp{optional} is set to @samp{0}, the bootloader must +support the requested tag and be able to provide relevant information to the image +if it is available. If the bootloader does not understand the meaning of the requested +tag it must fail with an error. However, if it supports a given tag but the information +conveyed by it is not available the bootloader does not provide the requested tag in +the Multiboot2 information structure and passes control to the loaded image as usual. + +Note: The above means that there is no guarantee that any tags of type @samp{mbi_tag_types} +will actually be present. E.g. on a videoless system even if you requested tag @samp{8} +and the bootloader supports it, no tags of type @samp{8} will be present in the Multiboot2 +information structure. @node Address header tag -- 1.7.10.4