From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: [Cbe-oss-dev] [PATCH] Ignore memory listed in PS3 device tree From: David Woodhouse To: michael@ellerman.id.au In-Reply-To: <1175570169.30552.3.camel@shinybook.infradead.org> References: <1175208237.3122.78.camel@pmac.infradead.org> <26babf7b7398794f08e7417377b3facc@kernel.crashing.org> <1175473220.3144.1.camel@concordia.ozlabs.ibm.com> <432af8a0f928491e7d376923829f40a0@kernel.crashing.org> <1175568133.16182.15.camel@concordia.ozlabs.ibm.com> <1175570169.30552.3.camel@shinybook.infradead.org> Content-Type: text/plain Date: Tue, 03 Apr 2007 10:45:38 -0400 Message-Id: <1175611539.2665.30.camel@shinybook.infradead.org> Mime-Version: 1.0 Cc: linuxppc-dev list , nhorman@redhat.com, cbe-oss-dev List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, 2007-04-02 at 23:16 -0400, David Woodhouse wrote: > > > My question remains: shouldn't Linux get that > > > information from the device tree, instead? The > > > bootwrapper or bootloader can put it there. > > > > Yes it _should_, but it doesn't. > > It _used_ to. The 2.6.16 kernel just used the memory listed in the > device tree. That's _why_ we need this hack -- because when we boot > from > 2.6.16 with the memory listed in the device tree, it ends up getting > registered twice by the new kernel. Why _did_ we make this change? It makes /sbin/kexec unhappy too, since it doesn't like the apparent lack of _any_ memory. It's not as if anyone's going to be expanding the amount of memory in their PS3, so it really needs to be dynamically detected. If we were to put the memory back in the device-tree, and start with a single region up to 0x07c00000 followed by another region with the rest of it, then we wouldn't need the rmo_top hack to /sbin/kexec either. -- dwmw2