Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261347AbVETPbh (ORCPT ); Fri, 20 May 2005 11:31:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261417AbVETPbh (ORCPT ); Fri, 20 May 2005 11:31:37 -0400 Received: from alog0374.analogic.com ([208.224.222.150]:14533 "EHLO chaos.analogic.com") by vger.kernel.org with ESMTP id S261347AbVETPb3 (ORCPT ); Fri, 20 May 2005 11:31:29 -0400 Date: Fri, 20 May 2005 11:31:15 -0400 (EDT) From: "Richard B. Johnson" Reply-To: linux-os@analogic.com To: Jan-Benedict Glaw cc: Linux kernel Subject: Re: Screen regen buffer at 0x00b8000 In-Reply-To: <20050520141434.GZ2417@lug-owl.de> Message-ID: References: <20050520141434.GZ2417@lug-owl.de> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1433 Lines: 36 On Fri, 20 May 2005, Jan-Benedict Glaw wrote: > On Fri, 2005-05-20 09:48:35 -0400, Richard B. Johnson wrote: >> len = getpagesize(); >> if((fd = open("/dev/mem", O_RDWR)) == FAIL) >> ERRORS("open"); >> if((sp = mmap((void *)SCREEN, len, PROT, TYPE, fd, SCREEN))==MAP_FAILED) >> ERRORS("mmap"); > > Maybe you'd better not fiddle with physical memory, but use the device > abstraction that's ment to offer that interface? That is, use a > framebuffer driver and open /dev/fb* . > > MfG, JBG No room for any more drivers. This just writes to a small LCD on an embedded controller. There should be no reason why I can't write directly to the physical memory. Anything written to the physical screen buffer will show up on the screen, as long as page zero is selected. I think that I've discovered a bug. I know that what I have written gets to the screen buffer because I can read in back! This doesn't make any sense. Cheers, Dick Johnson Penguin : Linux version 2.6.11.9 on an i686 machine (5537.79 BogoMips). Notice : All mail here is now cached for review by Dictator Bush. 98.36% of all statistics are fiction. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/