From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from list by lists.gnu.org with archive (Exim 4.71) id 1bB6cO-00053s-8L for mharc-grub-devel@gnu.org; Thu, 09 Jun 2016 16:31:56 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51302) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bB6cG-0004zm-O1 for grub-devel@gnu.org; Thu, 09 Jun 2016 16:31:54 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bB6cC-0001qV-Iv for grub-devel@gnu.org; Thu, 09 Jun 2016 16:31:47 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:32965) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bB6cC-0001qP-A0 for grub-devel@gnu.org; Thu, 09 Jun 2016 16:31:44 -0400 Received: from aserv0022.oracle.com (aserv0022.oracle.com [141.146.126.234]) by userp1040.oracle.com (Sentrion-MTA-4.3.2/Sentrion-MTA-4.3.2) with ESMTP id u59KVfPU031983 (version=TLSv1 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Thu, 9 Jun 2016 20:31:41 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by aserv0022.oracle.com (8.13.8/8.13.8) with ESMTP id u59KVemu009978 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Thu, 9 Jun 2016 20:31:40 GMT Received: from abhmp0017.oracle.com (abhmp0017.oracle.com [141.146.116.23]) by aserv0121.oracle.com (8.13.8/8.13.8) with ESMTP id u59KVde4005353; Thu, 9 Jun 2016 20:31:39 GMT Received: from olila.local.net-space.pl (/10.175.235.163) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 09 Jun 2016 13:31:38 -0700 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 02/10] multiboot2: Clarify meaning of information request header tag Date: Thu, 9 Jun 2016 22:30:36 +0200 Message-Id: <1465504244-17175-3-git-send-email-daniel.kiper@oracle.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1465504244-17175-1-git-send-email-daniel.kiper@oracle.com> References: <1465504244-17175-1-git-send-email-daniel.kiper@oracle.com> X-Source-IP: aserv0022.oracle.com [141.146.126.234] X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.4.x-2.6.x [generic] 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, 09 Jun 2016 20:31:54 -0000 Signed-off-by: Daniel Kiper --- doc/multiboot.texi | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/doc/multiboot.texi b/doc/multiboot.texi index 27e5a2f..a7e3584 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 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} bootloader must +support (understand meaning of) requested tag(s) and be able to provide relevant +information to image if it is available. If bootloader do not understand meaning +of requested tag(s) it must fail with an error. However, if it support a given +tag(s) but information conveyed by it/them is not available bootloader can do not +provide requested tag(s) in Multiboot information structure and proceed further. + +Note: Above means that there is not 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 bootloader support it no tags of type @samp{8} will be present in Multiboot +information structure. @node Address header tag -- 1.7.10.4