Writing an OS in Rust: Testing

We will use Rust’s support for custom test frameworks to execute test functions inside our kernel. To implement a custom test framework for our kernel, we add the following to our :

Our runner just prints a short debug message and then calls each test function in the list. The unsafe function expects the address of the first I/O port of the UART as argument, from which it can calculate the addresses of all needed ports.

Source: os.phil-opp.com