Problem Statement

In systems programing it is sometimes required to place language objects at specific memory locations, like I/O registers, hardware interrupt vectors etc.

Show how language objects can be allocated at a specific machine addresses. Since most OSes prohibit access to the physical memory if it is not mapped by the application, as an example, rather than a physical address, take the address of some existing object (using suitable address operations if necessary).

For example:

Let's start with the solution:

MOVE.L #$12345678,$100000

myVariable equ $100000
MOVE.L #myVariable,D0
JSR printLong           ;some unimplemented printing routine.

MOVE.L #$FFFFFFFF,myVariable