Introduction

The OSLib is a collection of routines and data structures developed to help system programmers in implementing an OS or an application that directly accesses the hardware. In this sense it is similar to the Windows NT Hardware Abstraction Layer (HAL), the $\mu$Choices NanoKernel, or the HARTIK Virtual Machine (VM) Layer. On the other hand, the aim of the OSLib is not to abstract the hardware resources (like the cited works do). In fact, hardware resources abstraction can result in poor efficiency and flexibility, as stated by Engler et others (ExoKernel). The OSLib code, instead of abstracting hardware, provides a secure and easy access to it hiding implementation details (for example, the PIC or PIT programming, or the CPU tables management) and leaving to the OS developers the hi-level and conceptual part of the work.