# Linux Kernel Module Cheat
The perfect emulation setup to study and develop the <<linux-kernel>> v5.9.2, kernel modules, <<qemu-buildroot-setup,QEMU>>, <<gem5-buildroot-setup,gem5>> and x86_64, ARMv7 and ARMv8 <<userland-assembly,userland>> and <<baremetal-setup,baremetal>> assembly, <<c,ANSI C>>, <<cpp,C++>> and <<posix,POSIX>>. <<gdb>> and <<kgdb>> just work. Powered by <<about-the-qemu-buildroot-setup,Buildroot>> and <<about-the-baremetal-setup,crosstool-NG>>. Highly automated. Thoroughly documented. Automated <<test-this-repo,tests>>.

#### 30.5.1. ARM NOP instruction

Parent section: Section 28.10, “NOP instructions”

There are a few different ways to encode NOP, notably MOV a register into itself, and a dedicated miscellaneous instruction.

Example: userland/arch/arm/nop.S

Try disassembling the executable to see what the assembler is emitting:

    gdb-multiarch -batch -ex 'arch arm' -ex "file v7/nop.out" -ex "disassemble/rs asm_main_after_prologue"

Bibliography: https://stackoverflow.com/questions/1875491/nop-for-iphone-binaries