From owner-freebsd-doc Wed Mar 13 08:57:56 1996 Return-Path: owner-doc Received: (from root@localhost) by freefall.freebsd.org (8.7.3/8.7.3) id IAA09738 for doc-outgoing; Wed, 13 Mar 1996 08:57:56 -0800 (PST) Received: from freenet.hamilton.on.ca (main.freenet.hamilton.on.ca [199.212.94.65]) by freefall.freebsd.org (8.7.3/8.7.3) with SMTP id IAA09733 for ; Wed, 13 Mar 1996 08:57:53 -0800 (PST) From: hoek@freenet.hamilton.on.ca Received: from james.freenet.hamilton.on.ca (james.freenet.hamilton.on.ca [199.212.94.66]) by freenet.hamilton.on.ca (8.6.12/8.6.12) with ESMTP id LAA14654; Wed, 13 Mar 1996 11:57:21 -0500 Received: (ac199@localhost) by james.freenet.hamilton.on.ca (8.6.12/8.6.12) id LAA11840; Wed, 13 Mar 1996 11:58:41 -0500 Date: Wed, 13 Mar 1996 11:58:40 -0500 (EST) To: Robin Lunn cc: doc@freebsd.org Subject: Re: Kernel only sees 64Mb of RAM In-Reply-To: <199603131458.QAA22752@admin.is.co.za> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-doc@freebsd.org X-Loop: FreeBSD.org Precedence: bulk On Wed, 13 Mar 1996, Robin Lunn wrote: > We've just installed FreeBSD 2.1.0-RELEASE onto a P-100 with 128Mb of ram. > The kernel (as yet only the GENERIC kernel) only sees 64Mb of memory. I see > no special definitions in the GENERIC kernel config file on my development > system that would cause it to be limited as such. >From question 8.6 of the FreeBSD-faq, :-) _________________________________________________________________ 8.6. I have 128 MB of RAM but it seems that the system use only the first 64 MB. What's going on ? Due to the manner in which FreeBSD gets the memory size from the BIOS, it can only detect 16 bits worth of Kbytes in size (65535 Kbytes = 64MB). If you have more than 64MB, FreeBSD will only see the first 64MB. To work around this problem, you need to use the kernel option specified below. There is a way to get complete memory information from the BIOS, but we don't have room in the bootblocks to do it. Someday when lack of room in the bootblocks is fixed, we'll use the extended BIOS functions to get the full memory information...but for now we're stuck with the kernel option. _________________________________________________________________ options "MAXMEM=" _________________________________________________________________ Where n is your memory in Kilobytes. For a 128 MB machine, you'd want to use 131072 _________________________________________________________________ -- tIM...HOEk.....Outnumbered, maybe, but outspoken?! NEVER!