# Serial outputing API

## Introduction

Shelter provide an abstraction around the serial port for outputing on it. This should act as the central point for outputing on the serial. The API is defined in `shelter/lib/include/cpu/serial.h` and implemented in `shelter/lib/src/cpu/serial.c`. This API obey the `serial_port_disabled` killswitch defined in kernel boot configuration. The subsystem prefix is `sh_serial_`.

## Overview

The API define the following elements:
- `sh_serial_load_serial_port_setting`: should be used only once at the start of the boot process to load the serial port setting using the argument `is_disabled` which is a `sh_bool`
- `sh_serial_send_byte`: safely (wait for previous byte to finish being send) send a byte to the serial port
The default and only serial port available is COM1.