Linux boot problem, pc does not point to virtual memory

[FISCHER Thierry]

Hi,
   
I am having some problem booting linux on Powerpc 405 (xilinx virtex4).

I have the following output on the terminal:
******************************************************
zImage starting: loaded at 0x00400000 (sp: 0x0070feb0)
Allocating 0x38a79c bytes for kernel ...
gunzipping (0x00000000 <- 0x0040d000:0x0059ee42)...done 0x367f58 bytes
Attached initrd image at 0x0059f000-0x0070ef20
initrd head: 0x1f8b0808
 
Linux/PowerPC load: console=ttyUL0 root=/dev/ram
Finalizing device tree... flat tree at 0x71c300
*******************************************************
 
The strange thing is that when I check the value of pc register, it does 
not return values of the virtual memory but values like:
pc :0x0000ebd4
pc :0x00002148
pc :0x00002194
pc :0x00002150 ...
Instead of values like 0xcXXXXXXX
 
It looks like there is a problem with the MMU or something like that ?
I have seen similar problems on the xilinx forum but it did not helped 
me so much:
http://forums.xilinx.com/xlnx/board/message?board.id=ELINUX&message.id=595&query.id=371581#M595 

http://forums.xilinx.com/xlnx/board/message?board.id=EDK&message.id=6235&query.id=367949#M6235 

 
If anyone has experienced similar problem please let me know.
Any suggestion is welcomed.
 
Thanks,