From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with archive (Exim 4.43) id 1O4WJR-00075Q-Bq for mharc-grub-devel@gnu.org; Wed, 21 Apr 2010 05:33:41 -0400 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1O4WJN-00074t-Be for grub-devel@gnu.org; Wed, 21 Apr 2010 05:33:37 -0400 Received: from [140.186.70.92] (port=37272 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1O4WJI-00073r-Kc for grub-devel@gnu.org; Wed, 21 Apr 2010 05:33:35 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1O4WJH-0004hs-Ar for grub-devel@gnu.org; Wed, 21 Apr 2010 05:33:32 -0400 Received: from mail-bw0-f225.google.com ([209.85.218.225]:51616) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1O4WJH-0004hg-59 for grub-devel@gnu.org; Wed, 21 Apr 2010 05:33:31 -0400 Received: by bwz25 with SMTP id 25so6919898bwz.8 for ; Wed, 21 Apr 2010 02:33:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from :user-agent:mime-version:to:subject:x-enigmail-version:content-type; bh=+HCiM3G1Awe4AgkRQTJKyUCfdP2G5swLHx4aVQOiqQI=; b=YcFAtwQwDB8TsGthRoPB3dPjGjL47I6WAskZmM6VubEOK4YUvlFk06UNlR+/a6tuaM 95AHYZ2LTkhA8CB+i6thrumXbS2/dJzJ0lvGLfDl6/oMZFxiXwyuO6d33BBc4pITYrFu nIkA//bPiwZxTn9J7EomX7NZLWKCrBt87ND/I= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:user-agent:mime-version:to:subject :x-enigmail-version:content-type; b=kYggYJy/bLoi1z0NLdOXu5DXcI0Qf/bt0qVZRQH0kCAXFiHwp14gakzT2109Z81euA DgD5cL9ZqnzvkrotBxbjK9RiZgh5XNbNU3SYFUlZmX8rgAZU5BXDodNow7D2CvSub7o/ oOradJ5zZixS7I4jqByN8WDvePp/UxV/378bM= Received: by 10.204.129.66 with SMTP id n2mr6680680bks.101.1271842410097; Wed, 21 Apr 2010 02:33:30 -0700 (PDT) Received: from debian.bg45.phnet (public-docking-hg-3-197.ethz.ch [129.132.246.197]) by mx.google.com with ESMTPS id 15sm4051899bwz.8.2010.04.21.02.33.29 (version=TLSv1/SSLv3 cipher=RC4-MD5); Wed, 21 Apr 2010 02:33:29 -0700 (PDT) Message-ID: <4BCEC661.7040909@gmail.com> Date: Wed, 21 Apr 2010 11:33:21 +0200 From: =?UTF-8?B?VmxhZGltaXIgJ8+GLWNvZGVyL3BoY29kZXInIFNlcmJpbmVua28=?= User-Agent: Mozilla-Thunderbird 2.0.0.22 (X11/20091109) MIME-Version: 1.0 To: The development of GRUB 2 X-Enigmail-Version: 0.95.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="------------enig8D70D7CF038F50E55323460E" X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 2) Subject: Multiboot physical and virtual addresses X-BeenThere: grub-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: The development of GNU GRUB List-Id: The development of GNU GRUB List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 21 Apr 2010 09:33:38 -0000 This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig8D70D7CF038F50E55323460E Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Hello, all. On i386 multiboot requires for paging to be disabled and on amd64 it will be required to map P=3DV so physical and virtual adresses are the same. However on MIPS it's inadequate to ask for bootloader to set such a mode because to do so one would need to go into mode with TLB activated and have TLB refill routines. It's much easier to run payload in "kernel mode" which is easy to use but is not P=3DV. I suppose on some= platforms it's even not possible to have such an easy mapping at all (especially openfirmware ones). So we have to decide which values will be used. I think that it should be virtual for a simple reason that it allows early startup to directly access the data even if it has no way of knowing what the v2p map is or before it setup its own paging table. Then when OS is initialising its own v2p map it should be able to remap virtual addresses to physical ones. The only problem is that some coders prefer to create a new v2p map in asm code and coding v2p converter in asm may be painful. I think the same applies for MMIO too. Possible alternatives: - supply physical addresses - supply both virtual and physical addresses. OS is able to choose the one it wants --=20 Regards Vladimir '=CF=86-coder/phcoder' Serbinenko --------------enig8D70D7CF038F50E55323460E Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iF4EAREKAAYFAkvOxmgACgkQNak7dOguQgnjXAEAn0HGpoiX6aVaxiESJEJtTaJF 7PML5JxayuzuU8f2k+8A/2k5BOzOwoZsB+XygGzJDS28NsvSJBeBo7jDhsgS9t0N =/fmq -----END PGP SIGNATURE----- --------------enig8D70D7CF038F50E55323460E--