Date: Fri, 16 Oct 2009 13:59:58 -0400 From: Jung-uk Kim <jkim@FreeBSD.org> To: freebsd-arch@FreeBSD.org Cc: Marcel Moolenaar <xcllnt@mac.com> Subject: Re: x86BIOS and the ISA bus and low memory in general... Message-ID: <200910161400.00564.jkim@FreeBSD.org> In-Reply-To: <200910161346.03066.jkim@FreeBSD.org> References: <20091015.085910.-520412456.imp@bsdimp.com> <4890688A-D2DB-431C-ADB6-03A39A8FD10E@mac.com> <200910161346.03066.jkim@FreeBSD.org>
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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 <jkim@FreeBSD.org> writes: > > > <snip> > > > > > > : 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? Jung-uk Kim > > I/O ports don't exist and there's a memory region for generating > > I/O port accesses, but the translation is not linear, so you > > can't work with a single base and port offset to get this to > > work. See ia64_ioport_address() in sys/ia64/ia64/machdep.c > > It seems there are PC-compatible inline functions {in,out}[bwl] in > sys/ia64/include/cpufunc.h. Will they work as I expect? > > Thanks, > > Jung-uk Kim
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