From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <4863FA88.1010708@freescale.com> Date: Thu, 26 Jun 2008 15:22:32 -0500 From: Scott Wood MIME-Version: 1.0 To: Stephen Neuendorffer Subject: Re: [PATCH] powerpc/bootwrapper: Add documentation of boot wrappertargets References: <20080625202104.30114.47902.stgit@trillian.secretlab.ca> <20080626164842.1D3AB1358053@mail15-sin.bigfish.com> <1214507238.7698.3.camel@weaponx> <20080626201643.D01221788058@mail223-wa4.bigfish.com> In-Reply-To: <20080626201643.D01221788058@mail223-wa4.bigfish.com> Content-Type: text/plain; charset=UTF-8; format=flowed Cc: John Linn , paulus@samba.org, linuxppc-dev@ozlabs.com, petermendham@computing.dundee.ac.uk List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Stephen Neuendorffer wrote: >> cuImage is for boards running an older U-Boot that does not understand >> device trees. > > Forgive my ignorance here, but what specifically does this imply? As > far as I can tell, generally speaking, some of the board-specific > information is passed into the boot wrapper, which then stuffs it into > the device tree. It implies that the binary is in uImage format, targets older u-boot (as opposed to some other bootloader entirely, which might be targeted with a dtbImage -- see adder875, for example), and has a device tree embedded. >> uImage is for device-tree aware U-Boot versions > > And this differs from above because it gets a device tree passed in, > which uboot has already stuffed correctly. Yes. >> dtbImage is used for boards that can take an ELF zImage, but still > need >> a dtb provided. >> >> simpleImage, not sure here. > > So both of these are elfs... but how do they differ? Is it only in how > the right head.s file gets picked up? Neither is necessarily an ELF. The only simpleboot target I see is a flat binary, as are some of the dtbImage targets (adder875, ep88xc, ep405, etc). simpleboot is more of a platform than an image type; it's a platform that assumes nothing about the firmware that loaded it, and gets all information from the embedded device tree. -Scott