# 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>>.

##### 30.4.4.2. ARM S suffix

Example: userland/arch/arm/s_suffix.S

The `S` suffix, present on most ARM data processing instructions, makes the instruction also set the Status register flags that control conditional jumps.

If the result of the operation is `0`, then it triggers BEQ, since comparison is a subtraction, with success on 0.

CMP sets the flags by default of course.