From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from exprod5og111.obsmtp.com (exprod5og111.obsmtp.com [64.18.0.22]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 9D2E1B7D1F for ; Thu, 3 Jun 2010 19:12:26 +1000 (EST) Message-ID: <4C0771F3.2000106@ge.com> Date: Thu, 03 Jun 2010 10:12:19 +0100 From: Martyn Welch MIME-Version: 1.0 To: Scott Wood Subject: Re: [PATCH] PowerPC: Remove hardcoded BAT configuration of IMMR in CPM early debug console References: <20100528151836.5889.10393.stgit@ES-J7S4D2J.amer.consind.ge.com> <4BFFECF1.9060809@freescale.com> <4C050295.408@ge.com> <4C050E84.2010602@ge.com> <4C053008.50306@freescale.com> <4C0610F8.6020801@ge.com> <4C068691.6040501@freescale.com> In-Reply-To: <4C068691.6040501@freescale.com> Content-Type: text/plain; charset=UTF-8 Cc: linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Scott Wood wrote: > On 06/02/2010 03:06 AM, Martyn Welch wrote: >>>>> I think that's a more fundamental change to CPM early debug than I >>>>> can >>>>> handle right now. >>> >>> Is IMMRBASE on your board at some address that has a low likelihood of >>> conflicting when treated as a kernel effective address? >> >> It's at 0x0f000000, is seems ok, but then I'm not sure I fully >> understand kernel effective addresses. > > That overlaps userspace -- is the BAT cleared before userspace starts? > To be honest, once I'd got the device booting past the early debug stage, I rebuilt the kernel without udbg in it... > If you don't want to do the fixmap stuff, might want to at least just > leave it at the current arbitrary effective address, which hasn't > seemed to cause much trouble so far. > Given that I've now switched udbg off in the kernel config, I really can't substantiate spending much more time on this. This patch was mainly to help others that maybe struggling to bring up Linux on a device with CPM serial. I'll try and get a revised patch out soon which keeps the current arbitrary effective address. Martyn > But fixmap is the right way to do it. > > -Scott -- Martyn Welch (Principal Software Engineer) | Registered in England and GE Intelligent Platforms | Wales (3828642) at 100 T +44(0)127322748 | Barbirolli Square, Manchester, E martyn.welch@ge.com | M2 3AB VAT:GB 927559189