Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755485Ab1F0XbP (ORCPT ); Mon, 27 Jun 2011 19:31:15 -0400 Received: from caramon.arm.linux.org.uk ([78.32.30.218]:45461 "EHLO caramon.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755482Ab1F0X3k (ORCPT ); Mon, 27 Jun 2011 19:29:40 -0400 Date: Tue, 28 Jun 2011 00:29:03 +0100 From: Russell King - ARM Linux To: Grant Likely Cc: Ohad Ben-Cohen , davinci-linux-open-source , Arnd Bergmann , Brian Swetland , Rusty Russell , linux-kernel@vger.kernel.org, akpm@linux-foundation.org, linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [RFC 1/8] drivers: add generic remoteproc framework Message-ID: <20110627232903.GB7736@n2100.arm.linux.org.uk> References: <1308640714-17961-1-git-send-email-ohad@wizery.com> <1308640714-17961-2-git-send-email-ohad@wizery.com> <20110627204958.GB20865@ponder.secretlab.ca> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110627204958.GB20865@ponder.secretlab.ca> User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1464 Lines: 41 On Mon, Jun 27, 2011 at 02:49:58PM -0600, Grant Likely wrote: > > +struct { > > + char magic[4] = { 'R', 'P', 'R', 'C' }; > > + u32 version; > > + u32 header_len; > > + char header[...] = { header_len bytes of unformatted, textual header }; > > + struct section { > > + u32 type; > > + u64 da; > > + u32 len; > > + u8 content[...] = { len bytes of binary data }; > > + } [ no limit on number of sections ]; > > +} __packed; > > Other have commented on the image format, so I'll skip this bit other > than saying that I agree it would be great to have a common format. (Don't have the original message to reply to...) Do we really want to end up with header being 5 bytes, header_len set as 5, and having to load/store all this data using byte loads/stores ? If we don't want that, then I suggest we get rid of the packed attribute, and require stuff to be naturally aligned. First issue is that struct section could be much better layed out: struct section { u32 type; u32 len; u64 da; u8 content[]; }; and require sizeof(struct section) % sizeof(u64) == 0 - iow, to find the next section, round len up to sizeof(u64). Ditto for the header. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/