"I guess the only "booting" (as in initialization) that would really be needed is to set the stack-pointer to an address above the memory that you will be using for your purposes."

If you are programming in 'C', part of the runtime support will be to cope with this, and other initialisations.
Depending on your compiler, this may need some used customisation - for details you will need to read the manual!
(in Keil C51, this is handled by startup.a51)