Subject: Uncompress Ok, but cannot run linux kernel...

From: "machael thailer" <[email-masked]>
Date: Sun, 6 May 2001 09:01:59 +0800

Hello:

    I have a 750-based custom board. I want to port linux-2.4.2 on it. The
bootrom code which initialized the hardware is working OK. I want to
download the linux kernel via TFTP(and it is OK now) and run it. But I met
some urgent problems ...
    I modified the bootloader codes according to arch/ppc/mbxboot/head.S and
other "printf" functions to suit my cases. And it runs like the following:

################################
Loading... 611056
Starting at 0x400000...

loaded at:     00400000 004952F0
zimage at:     004062C8 0048F994
avail ram:     004952F0 10000000

Linux/PPC load:
Uncompressing Linux...done.
Now booting the kernel
###################################

Then nothing happens(I have added a serial output code at the very begining
of arch/ppc/kernel/head.S and  have nothing output.). By printing the code
from 0x0 to 0x400000 I find the uncompressed code is right. After
uncompressing it jumps to 0x0(arch/ppc/mbxboot/head.S), but it cannot run .
Why?
Then I write a simple HelloWorld program  and compile it with -Ttext=0x0
compiling options, then use it to replace /usr/src/linux/vmlinux and
recompile the kernel.This time it works OK like the following:
################################
Loading... 4326
Starting at 0x400000...

loaded at:     ..........
zimage at:     ..........
avail ram:     ..........

Linux/PPC load:
Uncompressing Linux...done.
Now booting the kernel

Hello world
###################################

Here I attach my .config and arch/ppc/mbxboot/head.S. Hope you can help me
if you are free.

Thank you very much.

machael thailer