compact flash IDE boot image

Hi all,
I created a boot image for my m-systems compact flash 128 MB IDE drive and
am able to boot from it. In my build script I have added du, df and mount
commands . So when I boot into the system and do a df the process just

process exited …(0)

But when I mount the same drive on a normal qnx machine I can see that 110
MB is free.

Am i missing something basic here. How do I make the system show me what
amount of free space exists on the system. I currently have jsut 4 files on
the system ( .boot, .altbbot,.inode, .bitmap)

Similarly when I do a du I get a usage of about 490 MB when my hard disk is
only 128 MB.

I know i am missing something basic here, but could anybody tell me what i
am doing wrong

In my build file i mount my hard disk as

devb-eide blk automount=hdt077:/ &

Thanks in advance