From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marco Stornelli Subject: Re: [PATCH v2] char drivers: Ram oops/panic logger Date: Wed, 10 Mar 2010 13:15:25 +0100 Message-ID: <2ea1731b1003100415i46dd8fcem85b85f49fb1a479@mail.gmail.com> References: <4B968834.3040609@gmail.com> <21eaeb5a1003091808s2d7638cxd524952a7d84b378@mail.gmail.com> <2ea1731b1003100002w104633ffy1ae46ef3d245e5b5@mail.gmail.com> <21eaeb5a1003100120x6cd3f69ak598954af3c9fe955@mail.gmail.com> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:cc:content-type; bh=5MXQ7AYfsgnOdwebpT2Zn5GMN/xL59NFBsNSSzZknN4=; b=aJVBe1EUCRDNRG0RLl8NWu8iW3UWzutoh+MIMqIrTmwqOAS/ScXNnnRxr6L7InLoav dv3WnVZggj1QSWYVzXxSniBnq0ZGtdDE8yPQgnQ+J/8el7PBU4ZwY5mq8BVSHlREJZzF U3G1yvhakTBkTuvcBiJgos802fBd8wreeFZT0= In-Reply-To: <21eaeb5a1003100120x6cd3f69ak598954af3c9fe955@mail.gmail.com> Sender: linux-embedded-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Yuasa Yoichi Cc: Linux Kernel , Linux Embedded 2010/3/10 Yuasa Yoichi : > 2010/3/10 Marco Stornelli : >> 2010/3/10 Yuasa Yoichi : >>> Hi, >>> >>> 2010/3/10 Marco Stornelli : >>>> Ramoops, like mtdoops, can log oops/panic information but in RAM. >>> >>> What is different from mtdoops + mtd-ram? >>> >>> Yoichi >>> >> >> It can be used in a very easy way with persistent RAM for systems >> without flash support. For this systems, with this driver, it's no >> more needed add to the kernel the mtd subsystem with advantage in >> footprint as I said in the description. > > right. > But, > >> In addition, you can save >> flash space and store this information only in RAM. I think it's very >> useful for embedded systems. > > CONFIG_MTD_RAM uses only RAM. > I think there's no big difference about this point. > I meant with the "classic" use of mtdoops, therefore with a flash partition without use MTD_RAM. Using MTD_RAM, it's more or less the same thing, with the exception of "where" you want deploy the log. For example: if in your system you have got a nvram you can use it without problem, you need to specify the address of the nvram to the module. Very simple. I think it's a small driver but very useful, feedback from other embedded guys are welcome. Marco