[BusyBox] urgent help at change_root inside of initrd

[Stephan Linz]

Hi Folks,

since the last two days I've tried to make a so named "change_root" mechanism 
with support of kernels sysctrl (/proc/sys/kernel/real-root-dev) inside of a 
minimal initrd image. I use kernel 2.2.19 so I can't use the newer 
"pivot_root" mechanism. In kernel documentation initrd.txt says I have to 
write the major-minor code of the new root FS into the virtuell file 
/proc/sys/kernel/real-root-dev, but nothing is going on. Here my boot 
strategy (all things at x86 plattform):

BIOS boots from first master IDE device (LILO). LILO loads kernel and initrd 
image. Kernel mounts initrd image as first root FS in ramdisk(/dev/ram0); in 
lilo.conf is standing: append="root=/dev/ram init=/linuxrc rw". Initrd image 
covers a small busybox, /linuxrc is a shellscript and has to mount /dev/hda1, 
extract the real root FS from a tarball to /dev/ram1, unmount /dev/hda1 and 
mount /dev/ram1 as new root FS. So at the end of /linuxrc I write:

mount -t proc /proc /proc
echo 0x101 >/proc/sys/kernel/real-root-dev
exec /sbin/init

... BUT NOTHING IS CHANGED !!! :-(

Is there any step I've forgot? The same procedure with an existing root FS at 
/dev/hda3 has the same result. Please help me. I'm very desperate and under 
time pressure.
Stephan


Note: I've attached my current /linuxrc (debugging version)
-- 

======================================================================
Stephan Linz
Software Engineer

MAZeT GmbH                   Email:   mailto:linz at mazet.de
Branche office Jena          Phone:   +49-3641-2809-55
Göschwitzer Straße 32        Fax  :   +49-3641-2809-12
D-07745 JENA
Germany

Visit our web-pages: http://www.MAZeT.de
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