From owner-freebsd-arch@FreeBSD.ORG Fri Oct 16 19:04:18 2009 Return-Path: Delivered-To: freebsd-arch@FreeBSD.org Received: from [127.0.0.1] (freefall.freebsd.org [IPv6:2001:4f8:fff6::28]) by hub.freebsd.org (Postfix) with ESMTP id 673D71065679; Fri, 16 Oct 2009 19:04:18 +0000 (UTC) (envelope-from jkim@FreeBSD.org) From: Jung-uk Kim To: "M. Warner Losh" Date: Fri, 16 Oct 2009 15:04:07 -0400 User-Agent: KMail/1.6.2 References: <4890688A-D2DB-431C-ADB6-03A39A8FD10E@mac.com> <200910161400.00564.jkim@FreeBSD.org> <20091016.122539.-1383511515.imp@bsdimp.com> In-Reply-To: <20091016.122539.-1383511515.imp@bsdimp.com> MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <200910161504.09685.jkim@FreeBSD.org> Cc: xcllnt@mac.com, freebsd-arch@FreeBSD.org Subject: Re: x86BIOS and the ISA bus and low memory in general... X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 16 Oct 2009 19:04:18 -0000 On Friday 16 October 2009 02:25 pm, M. Warner Losh wrote: > In message: <200910161400.00564.jkim@FreeBSD.org> > > Jung-uk Kim writes: > : On Friday 16 October 2009 01:46 pm, Jung-uk Kim wrote: > : > On Thursday 15 October 2009 04:37 pm, Marcel Moolenaar wrote: > : > > On Oct 15, 2009, at 12:45 PM, M. Warner Losh wrote: > : > > > [[ redirected to arch@ ]] > : > > > > : > > > In message: <200910151431.53236.jkim@FreeBSD.org> > : > > > Jung-uk Kim writes: > : > > > > : > > > > : > > > : This is actually very interesting discussion for me > : > > > : because one of > : > > > > : > > > my > : > > > > : > > > : pet projects is extending x86bios to support non-PC > : > > > : architectures. If anyone is interested, the current > : > > > : source tarball is here: > : > > > : > : > > > : http://people.freebsd.org/~jkim/x86bios-20091015.tar.bz2 > : > > > : > : > > > : Especially, please see the code around #ifdef > : > > > : X86BIOS_COMPAT_ARCH. Basically, mapping I/O ports and > : > > > : orm(4) is missing. We don't have > : > > > > : > > > to > : > > > > : > > > : implement I/O ports but orm(4) vs. bus_space(9) is > : > > > : critical to make it a reality. Please consider it as a > : > > > : real practical example for orm, not just a blackhole > : > > > : driver. :-) > : > > > > : > > > I thought that most video cards had I/O ports as well as > : > > > video RAM that needed to be mapped... Am I crazy? > : > > > : > > It depends on the platform. On an Itanium machine I have the > : > > VGA frame buffer is at physical address 0xA0000-0xC0000. > : > > : > The address is the same, then. :-) > : > > : > > The only requirement is that you use non-cached I/O, > : > > otherwise you get a machine check. This can mean a > : > > non-identity mapping or not. It all depends... > : > > : > I couldn't find a way to manipulate memory attribute directly > : > on ia64, i.e., mem_range_attr_{get,set}() and > : > pmap_mapdev_attr() only exist on amd64 and i386. Does > : > pmap_mapdev() set the attribute as UC? > : > : It seems pmap_mapdev() on ia64 uses IA64_PHYS_TO_RR6() macro. If > : I read the source correctly, then it is gives UC mapped "view" of > : the physical address, right? If so, orm(4) can simply do > : pmap_mapdev()/pmap_unmapdev() around bus_space_read_region_1(). > : Am I right? > > I don't think that's the right solution here. The pmap_mapdev > stuff should happen when the resource is activated... For that, I guess we need another resource flag, e.g., RF_DEVICE, maybe? Jung-uk Kim