relative-addressing – Tarik Billa

How to use RIP Relative Addressing in a 64-bit assembly program?

September 23, 2023 by Tarik

I believe that you want to load the address of your string into %rsi; your code attempts to load a quadword from that address rather than the address itself. You want: lea msg(%rip), %rsi if I’m not mistaken. I don’t have a linux box to test on, however.

Why does the ARM PC register point to the instruction after the next one to be executed?

May 3, 2023 by Tarik

It’s a nasty bit of legacy abstraction leakage. The original ARM design had a 3-stage pipeline (fetch-decode-execute). To simplify the design they chose to have the PC read as the value currently on the instruction fetch address lines, rather than that of the currently executing instruction from 2 cycles ago. Since most PC-relative addresses are … Read more