TASKING VX-toolset for ARM User Guide

Chapter 8. Using the LinkerThis chapter describes the linking process, how to call the linker and how to control the linker with a scriptfile.The TASKING linker is a combined linker/locator. The linker phase combines relocatable object files(.obj files, generated by the assembler), and libraries into a single relocatable linker object file (.out).The locator phase assigns absolute addresses to the linker object file and creates an absolute object filewhich you can load into a target processor. From this point the term linker is used for the combinedlinker/locator.The linker can simultaneously link and locate all programs for all cores available on a target board. Thetarget board may be of arbitrary complexity. A simple target board may contain one standard processorwith some external memory that executes one task. A complex target board may contain multiple standardprocessors and DSPs combined with configurable IP-cores loaded in an FPGA. Each core may executea different program, and external memory may be shared by multiple cores.The linker takes the following files for input and output:This chapter first describes the linking process. Then it describes how to call the linker and how to useits options. An extensive list of all options and their descriptions is included in Section 12.5, Linker Options.To control the link process, you can write a script for the linker.This chapter shortly describes the purposeand basic principles of the Linker Script Language (LSL) on the basis of an example. A complete descriptionof the LSL is included in Linker Script Language.8.1. Linking ProcessThe linker combines and transforms relocatable object files (.obj) into a single absolute object file. Thisprocess consists of two phases: the linking phase and the locating phase.In the first phase the linker combines the supplied relocatable object files and libraries into a singlerelocatable object file. In the second phase, the linker assigns absolute addresses to the object file so itcan actually be loaded into a target.195