How to stop QNX boot sequence ?

This QNX is installed at a Flash Memory.
During the boot, the following messages appear:

Starting QNX …
Disk ‘/dev/ram’ contains 2048 blocks (1024K)
Net.ether8003: INITIALIZATION ERROR 10
Net.ether8003: INITIALIZATION ERROR 04
mv:source file not found. (/home/siubin/CONFIG.TXT).

I’d like to know if it’s possible to abort boot sequence before those messages. How can I do that ?

Thanks.

Marcelo