3 ms·
The instruction size is the first thing that is apparent. By looking at the pattern you can distinguish between fixed-sized, or variable-sized instructions, tel
by wladimir 15y ago
The instruction size is the first thing that is apparent. By looking at the pattern you can distinguish between fixed-sized, or variable-sized instructions, telling a lot about the architecture. ARM either has 16 bit (thumb mode) or 32 bit (normal) fixed-size instructions.
Also for every ISA there are some instructions that are very common, for example x86 has very-recognizable NOPs (0x90).
Having said that, seeing it is ARMv3 code specifically in one glance is pretty impressive.
- rcfox 15y ago> Having said that, seeing it is ARMv3 code specifically in one glance is pretty impressive. You seem to have added some hyperbole. There was no mention of "in one glance". Also, it's likely that he recognized that it was ARMvSomething (which is relatively easy) and then did some comparisons to narrow it down.