From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jamie Lokier Subject: Re: [PATCH v2] char drivers: Ram oops/panic logger Date: Mon, 15 Mar 2010 03:09:45 +0000 Message-ID: <20100315030945.GS6491@shareable.org> References: <4B968834.3040609@gmail.com> <21eaeb5a1003091808s2d7638cxd524952a7d84b378@mail.gmail.com> <2ea1731b1003100002w104633ffy1ae46ef3d245e5b5@mail.gmail.com> <21eaeb5a1003100120x6cd3f69ak598954af3c9fe955@mail.gmail.com> <2ea1731b1003100415i46dd8fcem85b85f49fb1a479@mail.gmail.com> <20100312144854.cb94d9b4.akpm@linux-foundation.org> <20100312233144.GG6491@shareable.org> <4B9B51B1.8010904@gmail.com> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: <4B9B51B1.8010904@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Marco Stornelli Cc: Andrew Morton , Yuasa Yoichi , Linux Kernel , Linux Embedded Marco Stornelli wrote: > Il 13/03/2010 00:31, Jamie Lokier ha scritto: > > That'd be fine if the kernel link scripts choose the address, as long > > as it's consistent between different compiles and similar > > configurations. That'd be a bit simpler than the admin having to know > > the memory map well enough to choose an address. > > > > -- Jamie > > > > I agree, but the bootloader should be aware of it. I mean, usually > bootloaders at boot, reset the RAM, so you have to tell to the > bootloader that you are using a piece of RAM as persistent RAM, for > example U-Boot has got a specific option CONFIG_PRAM. I don't know if > all the process can be completely transparent to the admin in all > situations. Sometimes you can't change the bootloader (they don't always come with source code). Or you could, but you don't want to risk it (there isn't always a way to recover if you break it). Obviously then the feature is only useful when the bootloader doesn't clear all the RAM :-) On slow boards in consumer devices, they sometimes avoid clearing the RAM because that adds measurable boot time. -- Jamie