Port Linux w/ mbxboot to PPCBoot system

[Wolfgang Denk]

Dear Jessica,

in message <002701c6601f$15b27f30$9afea8c0 at tcdomain.com> you wrote:
> 
>      I am new to embedded system, I am studying ppcboot-1.1.5 and linux
> kernel-2.4.4 that comes with an mpc852 base board, we want to modify it in

Both PPCBoot and Linux 2.4.4 are *hoplessly* obsolete. It may  be  ok
to study this to understand the workings, but please don't even dream
of using it for any current work.

> the future.  In the build process, they use the zImage.initrd
> (arch/ppc/mbxboot/zvmlinux.initrd) instead of the raw Linux kernel image

Somebody didn't know what he was doing, it seems.

> since ppcboot is already running, what happens when I boot the kernel that
> has old boot loader code in arch/ppc/mbxboot?  Will some parameters be
> overwritten?  If not, why?

The Linux bootstrap loader code (arch/ppc/mbxboot)  will  ignore  the
parameteres  passed  by  U-Boot,  will set up is own (hardwired), and
duplicate some of the things that PPCboot did or would do.

>      I am very tempted to follow the README to re-build the kernel with only
> vmlinux.gz and port it, but I don't want to create any un-recoverable
> results.  So I am here to seek advice, maybe this is something obvious to
> many people.

Don't change anything. Look at it, then drop it. Start using  current
code, i. e. a recent version of U-Boot and a recent Linux kernel.

Best regards,

Wolfgang Denk

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