From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTP id B40E02BDB3 for ; Fri, 1 Oct 2004 09:35:59 +1000 (EST) From: Benjamin Herrenschmidt To: jonathan@jonmasters.org In-Reply-To: <35fb2e59040930160254f00fce@mail.gmail.com> References: <35fb2e59040930160254f00fce@mail.gmail.com> Content-Type: text/plain Message-Id: <1096586504.3124.20.camel@gaston> Mime-Version: 1.0 Date: Fri, 01 Oct 2004 09:21:50 +1000 Cc: linuxppc-embedded@ozlabs.org Subject: Re: bi_recs List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fri, 2004-10-01 at 09:02, Jon Masters wrote: > Hi all, > > Would someone (Tom, Matt, Cort, Paul or Dan?) please tell me what the > status is of bi_recs? > > I first discussed the idea of this at the FOSDEM and not much has come > of it - but I would be happy to work on getting flexible system > configuration to the kernel on ppc without OF as this will then allow > a stock kernel without any need for builtin notions of memory layout. > Am I missing something that's already been implemented? bi_recs were supposed to evolve in that direction but that never happened. On the other hand, on ppc64, I took a different approach and decided that an OF tree would be mandatory, but you don't need OF to have one. I rewrote prom_init (the interface to OF) so that instead of tapping kenrel globals directly and generating struct device_node, it generates a flattened version of the device-tree and passes that to the kernel. That means that if you can provide a "blob" with such a tree in it, you can bypass prom_init. The tree doesn't need to be complete (like it doesn't need to contain all the PCI devices) and generating such a flattened tree from userland, from a text file for example, should be easy, or generate one from whatever infos your bootloader provides. But on the other hand, I've given up a long time ago trying to enforce any kind of sane model on ppc32 because the embedded folks only care about having a quick ugly broken hack to work with their board, thus the explosion of various incompatible boot_info structures that we have nowadays. Ben.