From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from imap.sh.mvista.com (unknown [63.81.120.155]) by ozlabs.org (Postfix) with ESMTP id EE89C67BC8 for ; Fri, 29 Sep 2006 06:53:26 +1000 (EST) Message-ID: <451C3641.60107@ru.mvista.com> Date: Fri, 29 Sep 2006 00:53:21 +0400 From: Sergei Shtylyov MIME-Version: 1.0 To: Segher Boessenkool Subject: Re: [PATCH] Start arch/powerpc/boot code reorganization References: <1158787957.6002.307.camel@localhost.localdomain> <20060920215738.GC24809@mag.az.mvista.com> <20060921133707.GA29137@gate.crashing.org> <1CA5168F-9ECA-4AA2-92AE-F86579245855@kernel.crashing.org> <20060922012408.GA13820@mag.az.mvista.com> <9F654F4A-B344-4374-8BDC-77FB0DDAFDCC@kernel.crashing.org> <20060922185923.GB25738@mag.az.mvista.com> <74E4B2E4-B59C-4998-B9FC-A77245C6AF6B@kernel.crashing.org> <20060923081836.GA25298@mag.az.mvista.com> In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Cc: Matt Porter , Paul Mackerras , linuxppc-dev@ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hello. Segher Boessenkool wrote: >>>Yes. Except a "cell" is not what you think it is. A "cell" is the >>>size of numbers OF deals with internally; just deal with it. Of >>>course, there's things like "#address-cells", which really mean >>>"#-32bit-things-per-address". >>Okay, well, when I talked about cells I meant "#-32bit-things-per- >>address". >>Obviously it was silly of me to think that "#address-cells" meant >>the # of >>address cells... > Some background might clear things up (or not)... A "cell" is the > unit of data in a Forth system. When OF was young (and not yet > called OF), all systems were 32-bit, and the 32-bit-thingies in > the properties (which weren't yet called properties) in the device > tree were called cells as well. When 64-bit came into the picture, > everything fell apart. The "correct" name for the property thingies > now is "integers as encoded with encode-int". I looked into the OF 64-bit extensions spec, and "cell" is 64-bit there. So, "address" should look valid. I don't know whether PPC64 boxes support 64-bit OF, or only 32-bit, however, the kernel doesn't seem to deal with 64-bit ones correctly, so I'm assuming that 32-bit OF is at least available... Anyway, I'm still missing the point of not using "address" which is clearly intended for such case. WBR, Sergei