BREAK_TO_DEBUGGER vs. machdep.enable_panic_key=1

[Alexander Best]

just wanted to ask what the difference between the following ways of enabling
the panic key is:

options BREAK_TO_DEBUGGER (kernelconf)

machdep.enable_panic_key=1 (sysctl)

i first thought having BREAK_TO_DEBUGGER in the kernelconf would change the
default setting of machdep.enable_panic_key from 0 to 1, but both options
don't seem to be linked to each other.

alex