From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: To: Matthew McClintock From: Wolfgang Denk Subject: Re: [RFC] New target 'cuImage' - compatibility uImage Mime-version: 1.0 Content-type: text/plain; charset=ISO-8859-1 In-reply-to: Your message of "Thu, 03 Aug 2006 10:29:05 CDT." <1154618945.5094.6.camel@localhost> Date: Thu, 03 Aug 2006 22:00:43 +0200 Sender: wd@denx.de Message-Id: <20060803200043.0EF78352660@atlas.denx.de> Cc: linuxppc-dev List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , In message <1154618945.5094.6.camel@localhost> you wrote: > > > In my understanding, an "uImage" file is a image consisting of an > > U-Boot header (64 bytes) followed by an (compressed or uncompressed) > > Linux kernel image. > > Yes OK. > I mean that the data contained within the uImage is compressed. In this This is only one option. Some configurations prefer to use uncom- pressed images because these canbe booted faster. > case where the uImage data is compressed I choose to skip compressing > the kernel section in the zImage (because have it compressed twice was > wasteful) We don't use zImage ! > So to clarify. The current method has a zImage with a compressed kernel No, it does not. We do not use zImage (which includes bootstrap wrapper code). U-Boot uses a plain stripped and compressed kernel image, i. e. something like this: objcopy -O binary vmlinux vmlinux.bin gzip -f -9 vmlinux.gz mkimage ... -C gzip -d vmlinux.gz uImage > section where the actual kernel lives. The zImage uncompressed this code > to the kernel load address. The 'cuImage' would be packaged in a uImage > with the entire zImage compressed, except in this case the kernel > section would not be compressed (to avoid have a compressed image within > a compressed image) You would have to create a new image type which has executable code at the start and carries the kernel image as payload, similar to what zImage does. Best regards, Wolfgang Denk -- Software Engineering: Embedded and Realtime Systems, Embedded Linux Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd@denx.de The shortest unit of time in the multiverse is the News York Second, defined as the period of time between the traffic lights turning green and the cab behind you honking. - Terry Pratchett, _Lords and Ladies_