Virtual Memory Interface

7.1 Introduction

VxWorks provides two levels of virtual memory support. The basic level is bundled with VxWorks and provides caching on a per-page basis. The full level is unbundled, and requires the optional component, VxVMI. VxVMI provides write protection of text segments and the VxWorks exception vector table, and an architecture-independent interface to the CPU's memory management unit (MMU). For information on how to install VxVMI, see Tornado Getting Started.

This chapter contains the following sections:

The first describes the basic level of support.

The second describes configuration, and is applicable to both levels of support.

The third and fourth parts apply only to the optional component, VxVMI:

The third is for general use, discussing the write protection implemented by VxVMI.

The fourth describes a set of routines for manipulating the MMU. VxVMI provides low-level routines for interfacing with the MMU in an architecture-independent manner, allowing you to implement your own virtual memory systems.