# Linux Kernel Module Cheat

### 28.5. Userland assembly C standard library

All examples except the Freestanding programs link to the C standard library.

This allows using the C standard library for IO, which is very convenient and portable across host OSes.

It also exposes other non-IO functionality that is very convenient such as `memcmp`.

The C standard library infrastructure is implemented in the common userland / baremetal source files:

- lkmc.c

- lkmc.h

- lkmc/aarch64.h

- lkmc/arm.h

- lkmc/x86_64.h

- Freestanding programs