From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from farnsworth.org (xyzzy.farnsworth.org [65.39.95.219]) by ozlabs.org (Postfix) with SMTP id 4BF2EDDE9B for ; Fri, 30 Nov 2007 03:10:43 +1100 (EST) Date: 29 Nov 2007 09:09:43 -0700 Message-ID: <20071129160943.15336.qmail@farnsworth.org> From: "Dale Farnsworth" To: linuxppc-embedded@ozlabs.org Subject: Re: The question about the high memory support on MPC8360? In-Reply-To: References: <396305910.05464@tsinghua.org.cn> <474E6A58.2070200@gdatech.co.in> Cc: List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Robert lazarski wrote: > On Nov 29, 2007 2:29 AM, vijay baskar wrote: > > > > How to make the linux find the total 2GB memory? > > > > Hi Friend, > > > > I hope u had tracked the conversion that has been going on. The max mem > > that the kernel can show is only 768 MB because only that of memory is > > directly mapped with your ram.. No matter how much ram > 768 MB (in > > powerpc.. it varies in other architectures) u have, the kernel will show > > only 768 MB.. This is called low mem.. > > > > How t o use high mem?? > > > > scott can probably guide us on this.. I also have lot of confusions about > > high mem.. Also i would suggest you a bit of reading on virtual memory > > management on linux to get a grasp about how things are done > > Rest for scott > > > > regards, > > vijai > > I also have a requirement to use more than 768MB and 0x30000000. I > have other problems at the moment, so I haven't tested this completely > yet. My limited understanding, though, is that to use more than 768MB > you have to change your kernel configuration, including shifting the > kernel start address. This is what I plan on testing for 1GB when I > have time: > > CONFIG_ADVANCED_OPTIONS=y > CONFIG_LOWMEM_SIZE_BOOL=y > CONFIG_LOWMEM_SIZE=0x40000000 > CONFIG_KERNEL_START_BOOL=y > CONFIG_KERNEL_START=0xa0000000 > # CONFIG_CONSISTENT_START_BOOL is not set > # CONFIG_CONSISTENT_SIZE_BOOL is not set > # CONFIG_BOOT_LOAD_BOOL is not set > > If that works for current kernels, please respond to the list ;-) . Can't answer that question, but before trying that, have you tried CONFIG_HIGHMEM=y ? -Dale