From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTP id 3314EDDE0D for ; Thu, 4 Oct 2007 06:50:03 +1000 (EST) In-Reply-To: References: <20071003190140.GA19169@xyzzy.farnsworth.org> Mime-Version: 1.0 (Apple Message framework v752.2) Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed Message-Id: <0B763FCF-9EFD-48E5-B2D9-53EAB0396522@kernel.crashing.org> From: Kumar Gala Subject: Re: [PATCH] PPC 85xx failure with odd memory sizes and CONFIG_HIGHMEM Date: Wed, 3 Oct 2007 15:49:43 -0500 To: Rune Torgersen Cc: linuxppc-embedded@ozlabs.org List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Oct 3, 2007, at 2:34 PM, Rune Torgersen wrote: >> From: Dale Farnsworth >> >> The CONFIG_FSL_BOOKE mmu setup code fails when CONFIG_HIGHMEM=y >> and the 3 fixed TLB entries cannot exactly map the lowmem size. >> Each TLB entry can map 4MB, 16MB, 64MB or 256MB, so the failure >> is observed when the kernel lowmem size is not equal to the >> sum of up to 3 of those values. > > Does this mean you cannot run 1G of lowmem on a 85xx? > > On 82xx I run 1G of lowmem, and when we finaly upgrade our product > to a > 85xx something, Iw was planning on doing the same. The code would have to change to allow for 1G of lowmem. Max lowmem with KERNELBASE @ 0xc000_0000 is 768M. - k