From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Roese Date: Sat, 25 Aug 2012 10:48:35 +0200 Subject: [U-Boot] [PATCH 3/6] SPL: Port SPL framework to powerpc In-Reply-To: <5037D2CE.3080600@ti.com> References: <1345709565-28862-1-git-send-email-sr@denx.de> <1345709565-28862-4-git-send-email-sr@denx.de> <503663EE.9000902@ti.com> <50367371.7080206@denx.de> <50368523.4080107@ti.com> <50373883.5090601@denx.de> <503754D6.1050405@denx.de> <50375DD1.80508@denx.de> <503761E5.5020106@denx.de> <5037D2CE.3080600@ti.com> Message-ID: <50389163.6020505@denx.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On 08/24/2012 09:15 PM, Tom Rini wrote: >>> I still would like to move to my suggestion to not copy the header and >>> use the mkimage header values ih_load and ih_ep directly. Right now I >>> don't see any showstopper for doing it this way. I'll send a patch to >>> change this shortly (if everything works out). >> >> Hmmm. As it seems some SPL loading drivers (block like mmc, streaming >> like ymodem) are not that easily converted to skipping the header. So >> I'm not so sure if we should go this way after all... > > Maybe I'm missing something, but maybe we just need to mimic the > behavior full U-Boot does and if we haven't been loaded where we need to > execute, shift bits around? Of course its possible. The main problem is speed here. With the "problematic" drivers like mmc, you would need to copy the image a 2nd time, once from MMC to a temp. SDRAM location, and then to its final (load_addr) destination. With the current approach, the image is only copied once from MMC to SDRAM. The 2nd copy shouldn't take that long though. Its SDRAM to SDRAM after all. I really do like Daniel's approach, with the decompression support: http://dev.phrozen.org/gitweb/?p=uboot-upstream.git;a=commitdiff;h=39165fa145b2d959f1eaa6faa3ab3053823bb985 We should try to merge this into the current SPL framework. I'll try to look into this next week. Thanks, Stefan