From owner-freebsd-arch@FreeBSD.ORG Wed Feb 13 20:56:50 2013 Return-Path: Delivered-To: freebsd-arch@freebsd.org Received: from mx1.freebsd.org (mx1.FreeBSD.org [8.8.178.115]) by hub.freebsd.org (Postfix) with ESMTP id 109DE506 for ; Wed, 13 Feb 2013 20:56:50 +0000 (UTC) (envelope-from marcel@xcllnt.net) Received: from mail.xcllnt.net (mail.xcllnt.net [70.36.220.4]) by mx1.freebsd.org (Postfix) with ESMTP id EAFE8EC1 for ; Wed, 13 Feb 2013 20:56:49 +0000 (UTC) Received: from lrust-sslvpn-nc.jnpr.net (natint3.juniper.net [66.129.224.36]) (authenticated bits=0) by mail.xcllnt.net (8.14.6/8.14.6) with ESMTP id r1DKulLI064354 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=NO) for ; Wed, 13 Feb 2013 12:56:48 -0800 (PST) (envelope-from marcel@xcllnt.net) From: Marcel Moolenaar Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Subject: FDT on x86 and for non-fdtbus devices. Message-Id: <03A622DA-EFD4-4984-8FC3-CD8B4832C32E@xcllnt.net> Date: Wed, 13 Feb 2013 12:56:42 -0800 To: "freebsd-arch@FreeBSD.org Arch" Mime-Version: 1.0 (Mac OS X Mail 6.2 \(1499\)) X-Mailer: Apple Mail (2.1499) X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 13 Feb 2013 20:56:50 -0000 All, Here at Juniper we added support for FDT to x86 (we'll contribute that shortly). However, it's applicability is rather limited right now by virtue of needing the devices to be attached to fdtbus (directly or indirectly). This so that we can map from device_t to pnode_t. However, there's great value in being able to use the FDT to tweak the behaviour of any device in the system, and in particular when we don't need nor use FDT to enumerate them. What we like to do is to use the FDT to define properties for pretty much any kind of device. Examples are: 1. Allow the FDT to define the name by which an interface is to be created. 2. Enumerate smb devices so that we can attach drivers for them under smbus when we don't need FDT to find ichsmb itself. I think one way to state the problem in a generic way is: How can we obtain the FDT pnode_t given an arbitrary device_t and use the pnode_t to query for properties, etc. Are people already doing things like this? Is there an interest in being able to do things like this? Are changes to drivers to have them query FDT contributable at all or do people think such would be "pollution"? Thoughts? Ideas? -- Marcel Moolenaar marcel@xcllnt.net