From mboxrd@z Thu Jan 1 00:00:00 1970 From: Deepak Manohar Subject: Re: Trying fbcon in dom1,but take_over_console fails... Date: Fri, 20 May 2005 08:13:59 -0700 Message-ID: References: Reply-To: Deepak Manohar Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: Content-Disposition: inline List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Ian Pratt Cc: xen-devel@lists.xensource.com, Mark Hurenkamp List-Id: xen-devel@lists.xenproject.org Hi Mark, Was any progress made on this? Were you able to get X to run in one of the user domains? If not what is the status? Maybe you could give me some pointers on what needs to be done? Thanks Deepak On 4/8/05, Ian Pratt wrote: >=20 > > > I suspect you'd be better off getting the xencons to > > register as ttyS0 > > > (xencons=3DttyS0) so that it doesn't go anywhere near the > > console, and > > > compile in VT, VT_CONSOLE and DUMMY_CONSOLE. > > Tried that, as well as disabling VGA_CONSOLE, but no > > improvements :-(:-( however, when built as a module, it is > > somewhat easier to debug this problem in fbcon, since dom1 is > > still running after it segfaults, and I can still use dmesg > > to see the printk's (strange that they don't appear on the > > console...). >=20 > Do you actually need fbcon? You don't need it to run X in most setups. >=20 > [If you want the printk's to come out on the console, use the KERN_ALERT = prefix] >=20 >=20 > Ian >=20 > > > > > > Please let us know how you get on. > > > > Ok, here's what I found so far: > > > > Using printk statements, I was able to find the culprit, it > > seems to be the vc pointer which is not initialised properly. > > > > Here's the piece of code (from fbcon_startup): > > > > /* Setup default font */ > > if (!p->fontdata) { > > if (!fontname[0] || !(font =3D find_font(fontname))) > > font =3D get_default_font(info->var.xres, > > info->var.yres); > > > > DPRINTK("fbcon_startup: ca\n"); > > > > vc->vc_font.width =3D font->width; > > vc->vc_font.height =3D font->height; > > vc->vc_font.data =3D p->fontdata =3D font->data; > > vc->vc_font.charcount =3D 256; /* FIXME Need > > to support more fonts */ > > > > DPRINTK("fbcon_startup: cb\n"); > > > > } > > > > And the oops occurs between the two DPRINTK's... > > So I added a check at startup: > > > > static const char *fbcon_startup(void) > > { > > const char *display_desc =3D "frame buffer device"; > > struct display *p =3D &fb_display[fg_console]; > > struct vc_data *vc =3D vc_cons[fg_console].d; > > struct font_desc *font =3D NULL; > > struct module *owner; > > struct fb_info *info =3D NULL; > > struct fbcon_ops *ops; > > int rows, cols; > > int irqres; > > > > DPRINTK("fbcon_startup... fg_console: %d, vc: > > %d\n",fg_console,vc); > > > > This prints 0 for the fg_console (not necessarely a problem) > > as well as vc... > > which is defenately a problem since it is dereferenced later! > > > > Seems like the vc_cons is not setup right, I'll have to take > > a look into vt.c I guess. > > Could this be due to the missing ps/2 port on domU (since > > they are assigned to dom0)? > > > > Will report back when I know more. > > > > > > Regards, > > Mark. > > > > _______________________________________________ > > Xen-devel mailing list > > Xen-devel@lists.xensource.com > > http://lists.xensource.com/xen-devel > > >=20 > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xensource.com > http://lists.xensource.com/xen-devel >