Mastering Assembly Programming

The loop

The implementation of the loop is a bit long, and we have many more interesting things to fill the space allocated for this chapter, so refer to the accompanying source code for the full version. Here, however, we will examine certain parts of the implementation:

• Creating a stack frame and parameter markup: The procedure's prolog code would be just as usual-we allocate some space on the stack and save registers that we want not to be affected by the procedure, and that means all the registers we use in the procedure:

        run_vm:           push  ebp           mov   ebp, esp           sub   esp, 4 * 3           ; We only need 12 bytes for storing                                       ; the state of virtual cpu           push  eax ebx ecx edx esi  ; We will use these registers              virtual at ebp + 8         ; Assign local labels to parameters ...