From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Fainelli Subject: Re: Minimal x86 memory requirements Date: Tue, 15 Feb 2011 11:04:48 +0100 Message-ID: <201102151104.48976.florian@openwrt.org> References: <4D59C9D5.4080909@linux.intel.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:sender:from:to:subject:date:user-agent:cc :references:in-reply-to:organization:mime-version:content-type :content-transfer-encoding:message-id; bh=6cnolSeV+n15gw2zZgfMIKgVEzo/GOp1yjRO+OAhr10=; b=a4SCQ9/juEtEECZjCFvaUIj0QrtJU4bFF12ocTPRKagMbCGUyqE8SOhHZj/nduSBRu /ccURNOiLH1dmp94DlHCK2x9HUmitXa3QFor+r8wrlPw5iMDfrebBDNnrgKBtXfhe4FZ abAuT/NyXc+yxKFPsYCAaWU+jXXtVAMHCBR84= In-Reply-To: <4D59C9D5.4080909@linux.intel.com> Sender: linux-embedded-owner@vger.kernel.org List-ID: Content-Type: Text/Plain; charset="us-ascii" To: Darren Hart Cc: linux-embedded@vger.kernel.org Hello, On Tuesday 15 February 2011 01:33:25 Darren Hart wrote: > I'm looking to build a bare minimum x86 kernel that will boot and run > busybox, nothing else (and eventually less than that). Assuming I do > need USB-HID, IDE, and basic TCP/IP, what should I expect to be the > least RAM I could get away with just to boot off flash, get a getty, > login, and take a few directory listings. > > If anyone would like to point me where to RTFM, that would be > appreciated as well :-) OpenWrt runs currently on a RDC R-321x System-on-Chip which is i486 based [1] and usually designed with 16MB of RAM, the bzImage itself is around 768KB w/ the following features built-in: - TCP/IP networking - MTD support for CFI compatible NOR flashes - JFFS2/squashfs filesystem When I load additionnal modules to be able to do NAT/USB/FAT filesystems for instance, plus having must have daemons running (dnsmasq, dropbear, busybox, hostapd ...), I still have around 3MB of available RAM (for a 16MB RAM device). The filesystem itself is compressed using squashfs+lzma, and fits within 3MB (loadable modules are inside, usable image at [2]). So from my perspective, you should be able to do all of this with a 16MB RAM device, plus 4 to 8MB of Flash to be confortable with storing your filesystem. Hope that helps. [1]: http://wiki.openwrt.org/oldwiki/openwrtdocs/hardware/airlink101/ar525w [2]: http://downloads.openwrt.org/backfire/10.03.1-rc4/rdc/openwrt-rdc- squashfs-ar525w.img -- Florian