From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andre Renaud Subject: Re: [PATCH 1/2] ARM: Add Kconfig option to use mkimage -T kernel_noload Date: Thu, 01 Mar 2012 09:12:17 +1300 Message-ID: <4F4E86A1.8010506@bluewatersys.com> References: <1330473804-23348-1-git-send-email-swarren@nvidia.com> <20120229122942.GF3318@game.jcrosoft.org> <74CDBE0F657A3D45AFBB94109FB122FF17BDDF206A@HQMAIL01.nvidia.com> <20120229181430.GI3318@game.jcrosoft.org> <4F4E6F96.8080907@am.sony.com> <20120229191209.GN14173@pengutronix.de> <74CDBE0F657A3D45AFBB94109FB122FF17BDDF2122@HQMAIL01.nvidia.com> <20120229194409.GO14173@pengutronix.de> <74CDBE0F657A3D45AFBB94109FB122FF17BDDF2155@HQMAIL01.nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <74CDBE0F657A3D45AFBB94109FB122FF17BDDF2155-C7FfzLzN0UxDw2glCA4ptUEOCMrvLtNR@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Stephen Warren Cc: =?ISO-8859-1?Q?Uwe_Kleine-K=F6nig?= , Russell King , Nicolas Pitre , Peter De Schrijver , Olof Johansson , Tim Bird , Colin Cross , "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Jean-Christophe PLAGNIOL-VILLARD , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" List-Id: linux-tegra@vger.kernel.org On 01/03/12 08:59, Stephen Warren wrote: > Uwe Kleine-K=F6nig wrote at Wednesday, February 29, 2012 12:44 PM: > ... >> If you want to give incentive for U-Boot to improve, drop the target >> today. And note that at least people caring about boot time must not= use >> the kernel's uImage target anyhow. >=20 > If you enable the new config option in this patch, then the performan= ce > issue is solved; U-Boot doesn't copy the kernel image any more, and t= he > kernel decompressor can write directly to the appropriate location wi= thout > moving the image first (assuming your board boot script loads the uIm= age > to a non-conflicting address). I may have missed part of this, but isn't one of the points regarding this that the zImage decompressor always runs with data cache disabled, resulting in a slow decompress, where as if the U-Boot decompressor is used (ie, gzipping the Image, and telling U-Boot to decompress), then i= t can run with caches enabled, improving boot speed? Thus the relocation issue is not really the speed hit, rather it is the image decompression. Regards, Andre