English Amiga Board - View Single Post - Making relocatable code

mcgeezer · 21 December 2018, 20:01

Hi all,

I've made use of the basereg directive in vasm today and it is really useful as it results in much cleaner/faster code.

To improve things further I'm looking at making my project completely PC relative and have been wondering the best way to reference memory pointers.

Consider the following snippet.

Code:

START: moveq #0,d0
           lea DATA(pc),a0
           rts

DATA:  dc.l   START

The pointer stored in DATA to START obviously breaks relocating the program, but is there a way in VASM to perhaps create offsets in the longword pointers instead of direct addresses?

The idea is that I need to load my program from a bootstrap that has allocated memory.

I hope this makes sense... I perhaps do not have some of the right terminology but I hope you know what I mean.

Geezer

21 December 2018, 20:01	#1
mcgeezer Registered User Join Date: Oct 2017 Location: Sunderland, England Posts: 2,702	Making relocatable code - vasm Hi all, I've made use of the basereg directive in vasm today and it is really useful as it results in much cleaner/faster code. To improve things further I'm looking at making my project completely PC relative and have been wondering the best way to reference memory pointers. Consider the following snippet. Code: START: moveq #0,d0 lea DATA(pc),a0 rts DATA: dc.l START The pointer stored in DATA to START obviously breaks relocating the program, but is there a way in VASM to perhaps create offsets in the longword pointers instead of direct addresses? The idea is that I need to load my program from a bootstrap that has allocated memory. I hope this makes sense... I perhaps do not have some of the right terminology but I hope you know what I mean. Geezer