3 ms·

For the jmp instruction, both source and destination are the rip register. That other thing is an immediate value. Really jmp is just mov or add, with the rip r

• ksaj 6y ago
  It was never legal to jump that way, though. And it wouldn't make sense if it was allowed by the cpu for your jump source to be somewhere you haven't been yet. So the $ "here" makes more sense, at least to me. Literally "from here, to there" versus "from there, to there." Here's a similar "illegal" re-envisioning of a call: push rip mov rip, _interrupt ; a weird illegal jump ... _interrupt: ... pop rip ; similarly illegal way to RET The workings are the same, but the cpu won't let you write it that way of course. The source and destination are still clear and intact because you start by pushing the source onto the stack before giving the destination, so it's at least good for demonstrating that bit of near-consistency in the Intel syntax. Part of the reason these rip shenanigans aren't allowed is because you'd have a hell of a time jumping or calling to a different SEG (segment), as INT always does, and the jumps can do if you need them to, because you'd have to push change the index pointer and the segment at the same time somehow. So you'd be limited to .COM (single segment memory images) file format with no interrupts if that's how you wanted to go about doing them. Simply "editing" rip, if you could, would stick you to a single memory segment.