From owner-freebsd-embedded@FreeBSD.ORG Fri Dec 28 21:55:59 2007 Return-Path: Delivered-To: embedded@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 2735116A418 for ; Fri, 28 Dec 2007 21:55:59 +0000 (UTC) (envelope-from marcelm@juniper.net) Received: from exprod7og104.obsmtp.com (exprod7og104.obsmtp.com [64.18.2.161]) by mx1.freebsd.org (Postfix) with ESMTP id DD30F13C46A for ; Fri, 28 Dec 2007 21:55:58 +0000 (UTC) (envelope-from marcelm@juniper.net) Received: from source ([66.129.224.36]) by exprod7ob104.postini.com ([64.18.6.12]) with SMTP; Fri, 28 Dec 2007 13:55:25 PST Received: from magenta.juniper.net ([172.17.27.123]) by emailsmtp56.jnpr.net with Microsoft SMTPSVC(6.0.3790.3959); Fri, 28 Dec 2007 13:55:16 -0800 Received: from mini-g4.jnpr.net (bennitzan-t60.jnpr.net [172.24.104.164] (may be forged)) by magenta.juniper.net (8.11.3/8.11.3) with ESMTP id lBSLtI990614; Fri, 28 Dec 2007 13:55:18 -0800 (PST) (envelope-from marcelm@juniper.net) Message-Id: <7C4C5641-EA0E-4BEA-8EEC-EEB69CDEE071@juniper.net> From: Marcel Moolenaar To: "Olivier Gautherot" In-Reply-To: Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (Apple Message framework v915) Date: Fri, 28 Dec 2007 13:55:18 -0800 References: <20071228.114559.-311937481.imp@bsdimp.com> <20071228.121213.-494094613.imp@bsdimp.com> <20071228.130329.43010549.imp@bsdimp.com> X-Mailer: Apple Mail (2.915) X-OriginalArrivalTime: 28 Dec 2007 21:55:16.0961 (UTC) FILETIME=[54FC5D10:01C8499C] Cc: embedded@freebsd.org Subject: Re: ocpbus(4) X-BeenThere: freebsd-embedded@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Dedicated and Embedded Systems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 28 Dec 2007 21:55:59 -0000 On Dec 28, 2007, at 12:31 PM, Olivier Gautherot wrote: >> : It violates newbus in that drivers compete for a device. >> : If the bus assigns the driver, then there's no competition >> : possible. The fact that the bus is abstract should not >> : mean that we should change its paradigm. >> >> No it doesn't. There's two kinds of busses in newbus. Those that >> self enumerate based on the hardware present (ie pccard, pci, usb, >> firewire) and then those that are told what's there (oldcard-style >> pccard, pure ISA, I2C, etc). The busses on the SoC more strongly >> resemble the latter than the former. The former busses already are >> enumerated with hints, but the actual mechanism is just a few calls >> that could be replaced with something better. > > Excuse my ignorance about obio, ocpbus and the like... > If we envisage to use a PCI-like approach to initialise the on-chip > drivers, couldn't we generate a table on a per CPUID basis? That's only part the story. There are embedded devices that aren't SoC. You can't use the CPU ID to figure out what's there in that case. You typically need to use board IDs, or SKUs for that. But other than that, yes. A description of the hardware is, when not fixed, keyed off of some easy to obtain ID or characteristic... -- Marcel Moolenaar marcelm@juniper.net