Contents Preface to the Jewel Edition of this report 1 1 A user-mode IRQ-logic server 1 2 State of the art 2 2.1 Definition of terms . . . . . . . . . . . . . . 2 2.2 IRQ-to-IPC translation . . . . . . . . . . . . 2 2.3 IRQ acknowledgement . . . . . . . . . . . . 2 2.4 IRQ priorities . . . . . . . . . . . . . . . . . 3 2.5 The problem . . . . . . . . . . . . . . . . . . 4 3 Omega0: The IRQ-logic server 4 3.1 A user-mode server . . . . . . . . . . . . . . 4 3.2 Problems with this design . . . . . . . . . . . 5 3.3 Requirements . . . . . . . . . . . . . . . . . 5 3.4 Omega0 interface . . . . . . . . . . . . . . . 6 3.4.1 Client connect and disconnect . . . . 6 3.4.2 IRQ handling . . . . . . . . . . . . . 6 3.4.3 Enumerating available IRQs . . . . . 7 3.5 Alternative interface . . . . . . . . . . . . . . 7 4 X86-specific Omega0-implementation issues 7 4.1 IRQ logic on x86-based PCs . . . . . . . . . 7 4.2 Requirements . . . . . . . . . . . . . . . .

Existing component models are targeted towards exible software design and load distribution between multiple nodes. These systems are mainly designed for interoperability. Thus, they are very general and exible, but slow. Building a microkernel-based system using existing component technology would result in bad overall system performance. We propose an approach to overcome the limitations of existing component systems while maintaining their advantages. This paper gives an overview of a new IDL compiler, FIDL, which uses knowledge of the underlying communication mechanism to improve the performance of component-based systems. 1 Introduction Microkernel-based systems are gaining more and more attention. They provide a exible approach to deal with the complexity of operating systems by dividing systems into smaller units or components. However, early systems like Chorus [10] or Mach [4] suered from poor inter process communication (IPC) performance. This resulted in the common opi...