From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?iso-8859-1?Q?Lo=EFc?= Minier Date: Fri, 3 Sep 2010 23:47:53 +0200 Subject: [U-Boot] zImage on ARM In-Reply-To: <20100902224542.48A63153A79@gemini.denx.de> References: <20100902224542.48A63153A79@gemini.denx.de> Message-ID: <20100903214753.GA8552@bee.dooz.org> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On Fri, Sep 03, 2010, Wolfgang Denk wrote: > > I have a client that has asked me to look into loading zImage files > > instead of uImage for some ARM based boards. > > Why? It's the direct output of the kernel build process; typically, distributions ship a /boot/zImage-foo which gets converted into an uImage and flashed if the bootloader is u-boot. If that step could be skipped, it would make things easier! > > Anyone familiar with the history of why uImage is the preferred > > format? Just trying to learn . . . > > uImage, when done correctly, avoids that you have to add a pre-loader > (including all of gzip and what else is needed to copy the uncom- > pressed image to it's final location in RAM) to each and every kernel > image - which is just a waste of time and resources as we already > have all that code present in U-Boot. > > Note that the mainline ARM kernel does not make use of this; instead, > it adds the preloader anyway. I never understood why. Seems zImage is quite widespread now; would it make sense to allow builing u-boot without that code and rely on the kernel code to unpack? Or should u-boot just gain a new image type for zImage? -- Lo?c Minier