Emulation-based fuzzing is a technique for security testing that executes firmware or other binary-only targets inside an instruction-set emulator (e.g., QEMU, Unicorn, or a custom emulator such as Icicle) instead of on real hardware. It is widely used for embedded systems, microcontroller firmware, and cellular basebands, where on-device testing is slow, impractical, or destructive. Modern emulation-based fuzzers add coverage-feedback instrumentation directly inside the emulator to guide input mutation, but historically such instrumentation has been bolted on in an ISA-specific, ad-hoc manner, restricting state-of-the-art fuzzing techniques to a few ISAs (x86/x86-64, ARM/AArch64). New fuzzing-specific emulators such as Icicle add instrumentation once in an architecture-agnostic way, enabling coverage-guided fuzzing across diverse ISAs including RISC-V, MIPS, and MSP430, and have been used to discover new bugs in real-world MSP430 firmware and to replicate results of ARM firmware fuzzers such as Fuzzware.