From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:51952) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TTxcy-0005H1-EE for qemu-devel@nongnu.org; Thu, 01 Nov 2012 12:28:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TTxcw-0000wG-Tc for qemu-devel@nongnu.org; Thu, 01 Nov 2012 12:28:20 -0400 Received: from mout.web.de ([212.227.15.3]:56604) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TTxcw-0000w4-Ji for qemu-devel@nongnu.org; Thu, 01 Nov 2012 12:28:18 -0400 Message-ID: <5092A317.5080606@web.de> Date: Thu, 01 Nov 2012 17:28:07 +0100 From: Jan Kiszka MIME-Version: 1.0 References: <5090C1B8.4060002@web.de> <50921D63.9@web.de> In-Reply-To: Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig8572B7943F231CF6BE690A36" Subject: Re: [Qemu-devel] ISA BIOS mapping for system flash emulation List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jordan Justen Cc: qemu-devel This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig8572B7943F231CF6BE690A36 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 2012-11-01 17:13, Jordan Justen wrote: > On Wed, Oct 31, 2012 at 11:57 PM, Jan Kiszka wrote:= >> On 2012-11-01 03:55, Jordan Justen wrote: >>> On Tue, Oct 30, 2012 at 11:14 PM, Jan Kiszka wrot= e: >>>> Hi Jordan, >>>> >>>> I was starring at pc_isa_bios_init and wondering why you are creatin= g a >>>> copy of the system flash for the low ISA range instead of using an a= lias >>>> here as well, just like old_pc_system_rom_init does. That means the = ISA >>>> BIOS range can run out of sync when the system flash is updated duri= ng >>>> runtime and requires a restart of QEMU then. Switching to an alias w= ould >>>> also allow some code consolidation. Can you explain the idea behind = the >>>> current version? >>> >>> I'm pretty sure I tried this and found that it did not work on the fl= ash device. >>> >>> I wrote an email to the list on Oct 17, 2011 about this, but I didn't= >>> get a response. (Re: [Qemu-devel] [PATCH 2/4] pc: Support system flas= h >>> memory with pflash) >> >> Can you be more specific how/when it failed? A trivial test cannot >> confirm this so far. >=20 > I reproduced this on 1b89fafe (where x86-flash was introduced). When I > setup the alias, I saw random data in the F000 segment. >=20 > When I tried the same thing on the current master (patch attached), it > appeared to work correctly. I vaguely remember issues with aliasing in the early memory region days, maybe that was causing it. As there is no conceptual reason to avoid an alias, let's file a refactoring patch. Jan --------------enig8572B7943F231CF6BE690A36 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.16 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://www.enigmail.net/ iEYEARECAAYFAlCSoxoACgkQitSsb3rl5xSJrwCdH7fm3r+WtUEUwowxIKlOae/p lgYAmgNL4G5RR6Z/GegyYoSzSsyj8k41 =Efc5 -----END PGP SIGNATURE----- --------------enig8572B7943F231CF6BE690A36--