From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from web36601.mail.mud.yahoo.com (web36601.mail.mud.yahoo.com [209.191.85.18]) by ozlabs.org (Postfix) with SMTP id 1BEE467B82 for ; Wed, 2 Aug 2006 13:49:08 +1000 (EST) Message-ID: <20060802034907.22411.qmail@web36601.mail.mud.yahoo.com> Date: Tue, 1 Aug 2006 20:49:07 -0700 (PDT) From: Parav Pandit Subject: Re: Booting Linux Kernel without bootloader To: Milton Miller , cthomas@Soneticom.com, linuxppc-embedded@ozlabs.org In-Reply-To: <11153922785140e0f761.861021530.miltonm@bga.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , --- Milton Miller wrote: > On Tue Jul 25 2006 05:30:39 PM CDT, Clint Thomas > wrote: > > > Basically, the system I want linux running on does > not require the > > initialization of hardware that U-boot provides, > or at least it does not > > need it to boot the linux kernel. I want to load > an uncompressed linux > > kernel into memory and start the execution of the > kernel, without using > > any kind of bootloader. Is this possible? Or does > linux need some kind > > of firmware or other software to tell it to start > executing? Thanks for > > any info you might have. > > To run a powerpc (not ppc, which will be removed) > kernel, in addition to the uncompressed kernel you > will need to supply a device tree structure, point > r3 to it, zero r5, and set r4 to the load address > (zero as you have described). See > Documentation/powerpc/booting-without-of.txt for > details. Then arrange for you processor to start > executing at address 0. Note that /vmlinux has an > elf header, you can use objcopy to remove it or > adjust r4 and your start point; the kernel will copy > itself to 0, clear bss and set up the stack. The > device tree structure must be placed above the bss > space in memory, not just the initialized data. Linux kernel does the bss cleaning after start_kernel() even though boot loader does it. So one step less. Parav > > milton > _______________________________________________ > Linuxppc-embedded mailing list > Linuxppc-embedded@ozlabs.org > https://ozlabs.org/mailman/listinfo/linuxppc-embedded > __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com