LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Gerd Hoffmann <kraxel@suse.de>
To: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Andi Kleen <ak@muc.de>, Andrew Morton <akpm@osdl.org>,
	linux-kernel@vger.kernel.org, virtualization@lists.osdl.org,
	xen-devel@lists.xensource.com, Chris Wright <chrisw@sous-sol.org>,
	Zachary Amsden <zach@vmware.com>, Alan <alan@lxorguk.ukuu.org.uk>
Subject: Re: [patch 02/21] Xen-paravirt: Handle a zero-sized VT console
Date: Wed, 14 Feb 2007 10:24:47 +0100	[thread overview]
Message-ID: <45D2D55F.4060605@suse.de> (raw)
In-Reply-To: <20070213221829.513618819@goop.org>

[-- Attachment #1: Type: text/plain, Size: 584 bytes --]

Jeremy Fitzhardinge wrote:
> If we're running under Xen, then there's no VT console.  This results
> in vc->vc_screenbuf_size == 0, which causes alloc_bootmem to panic.
> Don't bother allocating a vc_screenbuf if its going to be 0 sized.

NAK.

The *real* problem is that the real-mode boot code never ever runs, thus
SCREEN_INFO is not initialized (all zeros), and vgacon doesn't catch
that case.  Instead it thinks it runs on a EGA card with 0 lines and 0
columns.

So better fix vgacon to catch this and switch to the 80x25 dummy console
instead, patch attached.

cheers,

  Gerd


[-- Attachment #2: vgacon --]
[-- Type: text/plain, Size: 779 bytes --]

---
 drivers/video/console/vgacon.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Index: paravirt-2.6.20-hg749/drivers/video/console/vgacon.c
===================================================================
--- paravirt-2.6.20-hg749.orig/drivers/video/console/vgacon.c
+++ paravirt-2.6.20-hg749/drivers/video/console/vgacon.c
@@ -372,7 +372,8 @@ static const char *vgacon_startup(void)
 	}
 
 	/* VGA16 modes are not handled by VGACON */
-	if ((ORIG_VIDEO_MODE == 0x0D) ||	/* 320x200/4 */
+	if ((ORIG_VIDEO_MODE == 0x00) ||	/* SCREEN_INFO not initialized */
+	    (ORIG_VIDEO_MODE == 0x0D) ||	/* 320x200/4 */
 	    (ORIG_VIDEO_MODE == 0x0E) ||	/* 640x200/4 */
 	    (ORIG_VIDEO_MODE == 0x10) ||	/* 640x350/4 */
 	    (ORIG_VIDEO_MODE == 0x12) ||	/* 640x480/4 */

  parent reply	other threads:[~2007-02-14  9:24 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20070213221729.772002682@goop.org>
     [not found] ` <20070213221829.929261125@goop.org>
2007-02-13 22:39   ` [patch 06/21] Xen-paravirt: remove ctor for pgd cache Zachary Amsden
     [not found] ` <20070213221830.466651996@goop.org>
2007-02-13 22:45   ` [patch 13/21] Xen-paravirt: Add nosegneg capability to the vsyscall page notes Zachary Amsden
2007-02-13 22:49     ` Jeremy Fitzhardinge
2007-02-13 22:54       ` Zachary Amsden
2007-02-13 23:13         ` Jeremy Fitzhardinge
2007-02-14  5:38     ` [Xen-devel] " Rusty Russell
     [not found] ` <20070213221830.542511707@goop.org>
2007-02-13 22:53   ` [patch 14/21] Xen-paravirt: Add XEN config options and disable unsupported config options Dan Hecht
2007-02-13 23:29     ` Jeremy Fitzhardinge
2007-02-13 23:58       ` [Xen-devel] " Zachary Amsden
2007-02-13 23:58       ` Dan Hecht
     [not found] ` <20070213221830.238235953@goop.org>
2007-02-14  1:06   ` [patch 10/21] Xen-paravirt: Name: dont export paravirt_ops structure, do individual functions Zachary Amsden
2007-02-14  1:16     ` Jeremy Fitzhardinge
2007-02-14  1:18       ` Zachary Amsden
2007-02-14  1:37         ` Jeremy Fitzhardinge
2007-02-14  1:43           ` Zachary Amsden
2007-02-14  1:44             ` Jeremy Fitzhardinge
2007-02-14  5:51     ` Rusty Russell
2007-02-14 19:36     ` Christoph Hellwig
     [not found] ` <20070213221829.845132535@goop.org>
2007-02-14  1:23   ` [patch 05/21] Xen-paravirt: paravirt_ops: allocate a fixmap slot Dan Hecht
2007-02-14  1:36     ` Jeremy Fitzhardinge
2007-02-14  2:34       ` Dan Hecht
2007-02-14  8:43         ` Gerd Hoffmann
2007-02-14  8:37       ` [Xen-devel] " Jan Beulich
2007-02-14  9:15         ` Andi Kleen
     [not found] ` <20070213221829.513618819@goop.org>
2007-02-14  9:24   ` Gerd Hoffmann [this message]
     [not found] ` <20070213221830.707197267@goop.org>
2007-02-13 23:54   ` [patch 16/21] Xen-paravirt: Add code into head.S to handle being booted by Xen Andi Kleen
2007-02-14  0:39     ` Jeremy Fitzhardinge
2007-02-14  8:56       ` [Xen-devel] " Jan Beulich
2007-02-14 18:53     ` Jeremy Fitzhardinge
2007-02-14 20:10       ` Eric W. Biederman
2007-02-14 20:41         ` Jeremy Fitzhardinge
2007-02-14 21:06           ` Eric W. Biederman
2007-02-15  0:13             ` Jeremy Fitzhardinge
2007-02-15  1:39               ` Eric W. Biederman
2007-02-15  1:52                 ` Jeremy Fitzhardinge
2007-02-15  2:18                   ` Eric W. Biederman
2007-02-15  2:23                     ` Jeremy Fitzhardinge
2007-02-15  2:41                       ` Eric W. Biederman
2007-02-14 20:33   ` Eric W. Biederman
2007-02-14 20:42     ` Jeremy Fitzhardinge
     [not found] ` <20070213221831.150207238@goop.org>
2007-02-14 20:40   ` [patch 21/21] Xen-paravirt: Add the Xen virtual network device driver Eric W. Biederman
     [not found] ` <20070213221830.619562494@goop.org>
2007-02-14 20:45   ` [patch 15/21] Xen-paravirt: Add Xen interface header files Eric W. Biederman
2007-02-15  0:10     ` Jeremy Fitzhardinge
2007-02-15 17:32       ` Christoph Hellwig

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=45D2D55F.4060605@suse.de \
    --to=kraxel@suse.de \
    --cc=ak@muc.de \
    --cc=akpm@osdl.org \
    --cc=alan@lxorguk.ukuu.org.uk \
    --cc=chrisw@sous-sol.org \
    --cc=jeremy@goop.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=virtualization@lists.osdl.org \
    --cc=xen-devel@lists.xensource.com \
    --cc=zach@vmware.com \
    --subject='Re: [patch 02/21] Xen-paravirt: Handle a zero-sized VT console' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).