A GNU Development Environment forthe AVR MicrocontrollerRich [email protected] GNU Development Environment for the AVR Microcontrollerby Rich NeswoldPublished $Date$Copyright © 1999, 2000, 2001, 2002 by Richard M. Neswold, Jr.This document attempts to cover the details of the GNU Tools that are specific to the AVR family of processors.AcknowledgementsThis document tries to tie together the labors of a large group of people. Without these individuals’ efforts, wewouldn’t have a terrific, free set of tools to develop AVR projects. We all owe thanks to:• The GCC Team, which produced a very capable set of development tools for an amazing number of platforms andprocessors.• Denis Chertykov <[email protected]> for making the AVR-specific changes to the GNU tools.• Denis Chertykov and Marek Michalkiewicz <[email protected]> for developing the standard libraries andstartup code for AVR-GCC.• Uros Platise for developing the AVR programmer tool, uisp.• Joerg Wunsch <[email protected]> for adding all the AVR development tools to the FreeBSD(http://www.freebsd.org) ports tree and for providing the demo project in Chapter 2.• Brian Dean <[email protected]> for developing avrprog (an alternate to uisp) and for contributing Section1.4.1 which describes how to use it.Table of Contents1. Installing the GNU Tools..........................................................................................................................................11.1. GNU Binutils..................................................................................................................................................11.2. AVR-GCC ......................................................................................................................................................21.2.1. Downloading the Source....................................................................................................................21.2.2. Building the Project...........................................................................................................................21.2.3. Installing the Tools.............................................................................................................................21.3. AVR-LIBC......................................................................................................................................................31.3.1. Downloading the Source....................................................................................................................31.3.2. Building the Libraries........................................................................................................................31.3.3. Installing the Libraries and Header Files...........................................................................................31.4. Programming Your Processor.........................................................................................................................31.4.1. Using avrprog...................................................................................................................................31.4.2. Using uisp..........................................................................................................................................52. Using the GNU Tools.................................................................................................................................................62.1. The Project .....................................................................................................................................................62.2. Compiling and Linking ..................................................................................................................................82.3. “Map” Files ..................................................................................................................................................132.4. Generating .hex Files..................................................................................................................................152.5. Letting Make Build the Project ...................................................................................................................153. Application Start-up...............................................................................................................................................174. Standard C Library................................................................................................................................................194.1. Function Reference ......................................................................................................................................194.1.1. abort...............................................................................................................................................194.1.2. abs...................................................................................................................................................194.1.3. atoi.................................................................................................................................................194.1.4. atol.................................................................................................................................................204.1.5. bsearch ..........................................................................................................................................204.1.6. cos...................................................................................................................................................204.1.7. cosh.................................................................................................................................................214.1.8. div...................................................................................................................................................214.1.9. exit.................................................................................................................................................214.1.10. fabs...............................................................................................................................................214.1.11. isalnum, isalpha, isascii, isblank, iscntrl, isdigit, isgraph, islower, isprint,ispunct, isspace, isupper, isxdigit