From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Petr Vandrovec" Subject: Re: Card's view of framebuffer offset i Date: Mon, 15 Jul 2002 11:09:26 +0200 Sender: linux-fbdev-devel-admin@lists.sourceforge.net Message-ID: Mime-Version: 1.0 Content-Transfer-Encoding: Quoted-printable Return-path: Received: from zikova.cvut.cz ([147.32.235.100]) by usw-sf-list1.sourceforge.net with esmtp (Exim 3.31-VA-mm2 #1 (Debian)) id 17U1rZ-0007mN-00 for ; Mon, 15 Jul 2002 02:09:49 -0700 Errors-To: linux-fbdev-devel-admin@lists.sourceforge.net List-Help: List-Post: List-Subscribe: , List-Id: List-Unsubscribe: , List-Archive: Content-Type: text/plain; charset="iso-8859-1" To: Ville Syrjaelae Cc: linux-fbdev-devel@lists.sourceforge.net On 15 Jul 02 at 4:56, Ville Syrj=E4l=E4 wrote: > On Mon, Jul 15, 2002 at 02:02:14AM +0200, Petr Vandrovec wrote: > > On Sun, Jul 14, 2002 at 04:10:29PM +0300, Ville Syrj=E4l=E4 wrote: > > > Is there a way to ge the framebuffer offset to userspace? I hacked > > > DirectFB to draw to the crtc2 display but currently I've had to hard= code > > > the framebuffer offset. So I need something I can feed to tmy G400. > > > > In what environment? With matroxfb you have special framebuffer which > > is displayed by CRTC2 engine. > > > Offset is not explicitly exported, but > > if you'll take low 24 bits from fb_start, you'll get offset on > > G400/G450/G550 devices. > > I don't see such a thing anywhere. Do you mean smem_start? Ok just tried > with (smem_start + offset & 0x1ffffff) and it works for both heads. So > that's actually 25 bits. Maybe I should just use 28 bits to accomodate > larger framebuffers? No. You must use exactly 25 bits on G400/G450/G550 series, because of upper 7 bits are random: framebuffer apperture is 32MB on them, and upper 7 bits specify framebuffer position in PCI MMIO address space. Petr Vandrovec ------------------------------------------------------- This sf.net email is sponsored by:ThinkGeek Welcome to geek heaven. http://thinkgeek.com/sf