giving the user a boot option

[Ronald G. Minnich]

Is this assuming you have booted linux, or you want to boot linux from a 
bootloader that you give a command line option to? 

I actually implemented a little mod to linux that lets you modify the 
command line as it boots up, if you hit (e.g.) a space bar at the right 
time. I found no interest in the Linux community, but it is a trivial 
thing to write.

ron