Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762450AbZFNAtA (ORCPT ); Sat, 13 Jun 2009 20:49:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753382AbZFNAsw (ORCPT ); Sat, 13 Jun 2009 20:48:52 -0400 Received: from nwd2mail11.analog.com ([137.71.25.57]:40237 "EHLO nwd2mail11.analog.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753245AbZFNAsw (ORCPT ); Sat, 13 Jun 2009 20:48:52 -0400 X-IronPort-AV: E=Sophos;i="4.42,215,1243828800"; d="scan'208";a="2545515" Message-ID: <4A344782.2090707@analog.com> Date: Sun, 14 Jun 2009 08:42:42 +0800 From: Jie Zhang User-Agent: Mozilla-Thunderbird 2.0.0.19 (X11/20090103) MIME-Version: 1.0 To: Mike Frysinger CC: Jamie Lokier , uClinux development list , linux-kernel@vger.kernel.org, Greg Ungerer , uclinux-dist-devel@blackfin.uclinux.org, David McCullough Subject: Re: [uClinux-dev] [PATCH/RFC] FDPIC: add hook for arches to customize program header parsing References: <1244854869-2563-1-git-send-email-vapier@gentoo.org> <20090613161323.GC16220@shareable.org> <8bd0f97a0906130940j6b5e578bha8193f59d03c2f05@mail.gmail.com> <20090613182540.GJ16220@shareable.org> <8bd0f97a0906131732v5394eaf5gb0f7862dfe7f58f3@mail.gmail.com> In-Reply-To: <8bd0f97a0906131732v5394eaf5gb0f7862dfe7f58f3@mail.gmail.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 14 Jun 2009 00:42:54.0015 (UTC) FILETIME=[0DA1C4F0:01C9EC89] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1737 Lines: 40 Mike Frysinger wrote: > On Sat, Jun 13, 2009 at 14:25, Jamie Lokier wrote: >> Mike Frysinger wrote: >>> On Sat, Jun 13, 2009 at 12:13, Jamie Lokier wrote: >>>> Mike Frysinger wrote: >>>>> From: Jie Zhang >>>>> >>>>> The Blackfin port has custom program header flags/addresses for >>>>> automatically loading regions into the dedicated on-chip SRAM. So add a >>>>> hook for ports to leverage. >>>> It looks like a way for certain special executables to load themselves >>>> into fixed regions of the on-chip SRAM - and promptly crash if another >>>> executable does the same. Not so much a general executable format, as >>>> a hack to load something specific which should only be done once at a >>>> time. What am I missing here? >>> the addresses are keys, not fixed and/or "real" addresses >> Oh, I see that is indeed quite nice :-) >> >> I see it checks for both flags and special address values. Are the >> special address checks mainly historical, as usually flags/types are >> used to designate special memory types in ELF. > > the EF bits are more for smaller/statically linked applications where > you want to place the entire ELF into SRAM. the special PHDRs are for > selectively compiled code -- i.e. you've done a little bit of > profiling and testing and know which ones are the hot spots. Yes. Those e_flags works for the whole ELF file. And these specific addresses work as p_flags. May be in future I can add processor specific p_flags. Jie -- 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/