From owner-freebsd-arm@FreeBSD.ORG Sun Apr 19 17:48:02 2009 Return-Path: Delivered-To: arm@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 3F83A1065674 for ; Sun, 19 Apr 2009 17:48:02 +0000 (UTC) (envelope-from imp@bsdimp.com) Received: from harmony.bsdimp.com (bsdimp.com [199.45.160.85]) by mx1.freebsd.org (Postfix) with ESMTP id D78C28FC14 for ; Sun, 19 Apr 2009 17:48:01 +0000 (UTC) (envelope-from imp@bsdimp.com) Received: from localhost (localhost [127.0.0.1]) by harmony.bsdimp.com (8.14.2/8.14.1) with ESMTP id n3JHifvL092058; Sun, 19 Apr 2009 11:44:41 -0600 (MDT) (envelope-from imp@bsdimp.com) Date: Sun, 19 Apr 2009 11:45:41 -0600 (MDT) Message-Id: <20090419.114541.1355716995.imp@bsdimp.com> To: chuckr@telenix.org From: "M. Warner Losh" In-Reply-To: <49EB577A.1070006@telenix.org> References: <49EB577A.1070006@telenix.org> X-Mailer: Mew version 5.2 on Emacs 21.3 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: arm@freebsd.org Subject: Re: comparing archs X-BeenThere: freebsd-arm@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Porting FreeBSD to the StrongARM Processor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 19 Apr 2009 17:48:02 -0000 In message: <49EB577A.1070006@telenix.org> Chuck Robey writes: : -----BEGIN PGP SIGNED MESSAGE----- : Hash: SHA1 : : What would be a good arm cpu to use as a comparison, so that I can constrast the : Cortex-A8 Armv7A processor in my Pandora against the (whatever) processor which : would typify the Arm6 architecture that is already implemented in FreeBSD? That was rather the point of my earlier email: There aren't any armv6 processors implemented today. Much of the base code is there, but I don't think we have all the goo in place for an actual SoC. : Would there be one of those arm11** processors to do it, like maybe the arm1136? : Or another one? : : I found that the Arm folks don't release the Armv7 architecture document for the : latest version, you need to be a Arm vendor with a "business reason" to get : that. I got one for the Arm6 arch, but I'm not sure which particular one : typifies what FreeBSD's implemented already. The way to find out what is implemented is to grep the source. For example, the atmel AT91RM9200 uses an ARM920T core and implements armv4. The Marvel parts implement armv5 (with a few quirks). You can tell this by looking at either the cache operations that are defined for each port, or the bus space operations (they are often optimized for each rev of ARM spec). Warner