From owner-freebsd-hackers@FreeBSD.ORG Tue Aug 24 16:10:31 2010 Return-Path: Delivered-To: freebsd-hackers@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 4C0361065697; Tue, 24 Aug 2010 16:10:31 +0000 (UTC) (envelope-from imp@bsdimp.com) Received: from harmony.bsdimp.com (bsdimp.com [199.45.160.85]) by mx1.freebsd.org (Postfix) with ESMTP id 0A5188FC14; Tue, 24 Aug 2010 16:10:30 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by harmony.bsdimp.com (8.14.3/8.14.1) with ESMTP id o7OG59Oo066878; Tue, 24 Aug 2010 10:05:09 -0600 (MDT) (envelope-from imp@bsdimp.com) Date: Tue, 24 Aug 2010 10:05:20 -0600 (MDT) Message-Id: <20100824.100520.826498698880464924.imp@bsdimp.com> To: jhb@FreeBSD.org From: "M. Warner Losh" In-Reply-To: <201008241009.46624.jhb@freebsd.org> References: <201008171615.21103.jhb@freebsd.org> <20100823.220945.232861953240012158.imp@bsdimp.com> <201008241009.46624.jhb@freebsd.org> X-Mailer: Mew version 6.3 on Emacs 22.3 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: yanegomi@gmail.com, freebsd-hackers@FreeBSD.org Subject: Re: Why doesn't ppc(4) check non-ENXIO failures during probe? X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 24 Aug 2010 16:10:31 -0000 In message: <201008241009.46624.jhb@freebsd.org> John Baldwin writes: : On Tuesday, August 24, 2010 12:09:45 am M. Warner Losh wrote: : > In message: <201008171615.21103.jhb@freebsd.org> : > John Baldwin writes: : > : > So more or less it's for BIOSes with ISA that doesn't feature plug : > : > and play (286s, 386s, some 486s?)? Just trying to fill in the gap :). : > : : > : Yes, it may perhaps still be useful for some x86 embedded systems, though : > : it is doubtful that those would use a ppc(4) device perhaps. : > : > Many embedded x86 systems use ppc(4) as a DIO port. ppi attaches to : > it and can be used to frob bits. : > : > These days, of course, almost all boards have ACPI, so that means they : > get enumerated that way. Only boards that don't run windows might not : > have ACPI, in which case the devices are usually enumerated via : > PNPBIOS. But not always, since those boards tend to have the buggiest : > BIOSes on the planet in this area. Hints are needed on a few of these : > boards since nothing else will work. And they have Atom processors on : > them... : : The specific code I am referring to is the code in ppc_isa_probe() that tries : to auto-identify a ppc port by poking at various I/O ports directly. It is : not enabled by default. You'd have to have a ppc hint that did not include an : I/O port for this code to be triggered I think as it only gets executed if a : ppc(4) device does not have an I/O port resource from ACPI/PnPBIOS/hints. Ah, that code... Yes, you're right... : I was mostly thinking of this in terms of ISA cards, and I doubt that even : modern embedded systems have ISA slots. :) There are still a few PC-104 boards knocking around (which is ISA in a different form-factor), but mostly people have moved PC-104+ which is really PCI or other things... Warner