From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marek Vasut Date: Sat, 5 Nov 2011 23:06:47 +0100 Subject: [U-Boot] [PATCH v2 1/3] image: Make image_get_fdt work like image_get_{ram_disk, kernel} In-Reply-To: <20111105215302.789531893014@gemini.denx.de> References: <1320164902-24190-1-git-send-email-swarren@nvidia.com> <20111105215302.789531893014@gemini.denx.de> Message-ID: <201111052306.47844.marek.vasut@gmail.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de > Dear Simon Glass, > > In message you wrote: > > Just a quick Q. What is the ultimate intent here? Should we be aiming > > to have U-Boot copy and decompress the data into RAM ready for Linux? > > Yes. > > Rigth from the beginning of PPCBoot / U-Boot we designed it that > U-Boot would do all needed steps to verify, load and uncompress an > image. It make no sense to attach the uncompression and loading code > to each and every image, and to download it and store it again and > again and again. This works really well for example on Power, only > ARM is one of the examples where the PTB never bothered to acquaint > themself with ideas that went beyond the capabilities of Blob or > similar boot loaders. Right, there's no negotiation between linux and uboot on this topic. I think this is going on for ages now. > > > In theory this should be slightly faster since U-Boot already has the > > data in its cache. I think zImage now supports having an FDT inside > > but what is the advantage of zImage over a uImage with compressed > > portions? > > There is none. Also, there is no advantage in attaching the DT blob > to the Linux image/. This is only of use to braindead boot loaders. > > Best regards, > > Wolfgang Denk