How do I set a software breakpoint on an ARM processor?

Question

How do I do the equivalent of an x86 software interrupt:

asm( \"int $3\" )

on an ARM processor (specifically a Cortex A8) to generate an event

Answer 1

ARM does not define a specific breakpoint instruction. It can be different in different OSes. On ARM Linux it's usually an UND opcode (e.g. FE DE FF E7) in ARM mode and BKPT (BE BE) in Thumb.

With GCC compilers, you can usually use __builtin_trap() intrinsic to generate a platform-specific breakpoint. Another option is raise(SIGTRAP).