[c-nsp] Update CatOS to IOS

[coueffe charly]

Hi,

I'm a new supervisor card and she has a CatOS. I want update to IOS but 
i don't known a procedure and commands for CatOS.

I have configure an IP address and download a little IOS on a bootflash. 
When I have configure a boot sequence with my IOS I have a warning message.

My command is set boot system flash bootflash:<IOS> prepend

What are the commands ?

Thank you for your help,

Charlys