avr-libc  2.0.0
Standard C library for AVR-GCC

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Building and Installing the GNU Tool Chain

This chapter shows how to build and install, from source code, a complete development environment for the AVR processors using the GNU toolset. There are two main sections, one for Linux, FreeBSD, and other Unix-like operating systems, and another section for Windows.

Building and Installing under Linux, FreeBSD, and Others

The default behaviour for most of these tools is to install every thing under the /usr/local directory. In order to keep the AVR tools separate from the base system, it is usually better to install everything into /usr/local/avr. If the /usr/local/avr directory does not exist, you should create it before trying to install anything. You will need root access to install there. If you don't have root access to the system, you can alternatively install in your home directory, for example, in $HOME/local/avr. Where you install is a completely arbitrary decision, but should be consistent for all the tools.

You specify the installation directory by using the –prefix=dir option with the configure script. It is important to install all the AVR tools in the same directory or some of the tools will not work correctly. To ensure consistency and simplify the discussion, we will use $PREFIX to refer to whatever directory you wish to install in. You can set this as an environment variable if you wish as such (using a Bourne-like shell):

$ PREFIX=$HOME/local/avr
$ export PREFIX

Note
Be sure that you have your PATH environment variable set to search the directory you install everything in before you start installing anything. For example, if you use –prefix=$PREFIX, you must have $PREFIX/bin in your exported PATH. As such:
$ PATH=$PATH:$PREFIX/bin
$ export PATH
Warning
If you have CC set to anything other than avr-gcc in your environment, this will cause the configure script to fail. It is best to not have CC set at all.
Note
It is usually the best to use the latest released version of each of the tools.

Required Tools

Optional Tools

You can develop programs for AVR devices without the following tools. They may or may not be of use for you.

GNU Binutils for the AVR target

The binutils package provides all the low-level utilities needed in building and manipulating object files. Once installed, your environment will have an AVR assembler (avr-as), linker (avr-ld), and librarian (avr-ar and avr-ranlib). In addition, you get tools which extract data from object files (avr-objcopy), dissassemble object file information (avr-objdump), and strip information from object files (avr-strip). Before we can build the C compiler, these tools need to be in place.

Download and unpack the source files:

$ bunzip2 -c binutils-<version>.tar.bz2 | tar xf -
$ cd binutils-<version>
Note
Replace <version> with the version of the package you downloaded.
If you obtained a gzip compressed file (.gz), use gunzip instead of bunzip2.

It is usually a good idea to configure and build binutils in a subdirectory so as not to pollute the source with the compiled files. This is recommended by the binutils developers.

$ mkdir obj-avr
$ cd obj-avr

The next step is to configure and build the tools. This is done by supplying arguments to the configure script that enable the AVR-specific options.

$ ../configure --prefix=$PREFIX --target=avr --disable-nls

If you don't specify the –prefix option, the tools will get installed in the /usr/local hierarchy (i.e. the binaries will get installed in /usr/local/bin, the info pages get installed in /usr/local/info, etc.) Since these tools are changing frequently, It is preferrable to put them in a location that is easily removed.

When configure is run, it generates a lot of messages while it determines what is available on your operating system. When it finishes, it will have created several Makefiles that are custom tailored to your platform. At this point, you can build the project.

$ make
Note
BSD users should note that the project's Makefile uses GNU make syntax. This means FreeBSD users may need to build the tools by using gmake.

If the tools compiled cleanly, you're ready to install them. If you specified a destination that isn't owned by your account, you'll need root access to install them. To install:

$ make install

You should now have the programs from binutils installed into $PREFIX/bin. Don't forget to set your PATH environment variable before going to build avr-gcc.

GCC for the AVR target

Warning
You must install avr-binutils and make sure your path is set properly before installing avr-gcc.

The steps to build avr-gcc are essentially same as for binutils:

$ bunzip2 -c gcc-<version>.tar.bz2 | tar xf -
$ cd gcc-<version>
$ mkdir obj-avr
$ cd obj-avr
$ ../configure --prefix=$PREFIX --target=avr --enable-languages=c,c++ \
    --disable-nls --disable-libssp --with-dwarf2
$ make
$ make install

To save your self some download time, you can alternatively download only the gcc-core-<version>.tar.bz2 and gcc-c++-<version>.tar.bz2 parts of the gcc. Also, if you don't need C++ support, you only need the core part and should only enable the C language support. (Starting with GCC 4.7 releases, these split files are no longer available though.)

Note
Early versions of these tools did not support C++.
The stdc++ libs are not included with C++ for AVR due to the size limitations of the devices.

AVR LibC

Warning
You must install avr-binutils, avr-gcc and make sure your path is set properly before installing avr-libc.
Note
If you have obtained the latest avr-libc from cvs, you will have to run the bootstrap script before using either of the build methods described below.

To build and install avr-libc:

$ gunzip -c avr-libc-<version>.tar.gz | tar xf -
$ cd avr-libc-<version>
$ ./configure --prefix=$PREFIX --build=`./config.guess` --host=avr
$ make
$ make install

Optionally, generation of debug information can be requested with:

$ gunzip -c avr-libc-<version>.tar.gz | tar xf -
$ cd avr-libc-<version>
$ ./configure --prefix=$PREFIX --build=`./config.guess` --host=avr \
  --with-debug-info=DEBUG_INFO
$ make
$ make install

where DEBUG_INFO can be one of stabs, dwarf-2, or dwarf-4.

The default is to not generate any debug information, which is suitable for binary distributions of avr-libc, where the user does not have the source code installed the debug information would refer to.

AVRDUDE

Note
It has been ported to windows (via MinGW or cygwin), Linux and Solaris. Other Unix systems should be trivial to port to.

avrdude is part of the FreeBSD ports system. To install it, simply do the following:

# cd /usr/ports/devel/avrdude
# make install
Note
Installation into the default location usually requires root permissions. However, running the program only requires access permissions to the appropriate ppi(4) device.

Building and installing on other systems should use the configure system, as such:

$ gunzip -c avrdude-<version>.tar.gz | tar xf -
$ cd avrdude-<version>
$ mkdir obj-avr
$ cd obj-avr
$ ../configure --prefix=$PREFIX
$ make
$ make install

GDB for the AVR target

GDB also uses the configure system, so to build and install:

$ bunzip2 -c gdb-<version>.tar.bz2 | tar xf -
$ cd gdb-<version>
$ mkdir obj-avr
$ cd obj-avr
$ ../configure --prefix=$PREFIX --target=avr
$ make
$ make install
Note
If you are planning on using avr-gdb, you will probably want to install either simulavr or avarice since avr-gdb needs one of these to run as a a remote target backend.

SimulAVR

SimulAVR also uses the configure system, so to build and install:

$ gunzip -c simulavr-<version>.tar.gz | tar xf -
$ cd simulavr-<version>
$ mkdir obj-avr
$ cd obj-avr
$ ../configure --prefix=$PREFIX
$ make
$ make install
Note
You might want to have already installed avr-binutils, avr-gcc and avr-libc if you want to have the test programs built in the simulavr source.

AVaRICE

Note
These install notes are not applicable to avarice-1.5 or older. You probably don't want to use anything that old anyways since there have been many improvements and bug fixes since the 1.5 release.

AVaRICE also uses the configure system, so to build and install:

$ gunzip -c avarice-<version>.tar.gz | tar xf -
$ cd avarice-<version>
$ mkdir obj-avr
$ cd obj-avr
$ ../configure --prefix=$PREFIX
$ make
$ make install
Note
AVaRICE uses the BFD library for accessing various binary file formats. You may need to tell the configure script where to find the lib and headers for the link to work. This is usually done by invoking the configure script like this (Replace <hdr_path> with the path to the bfd.h file on your system. Replace <lib_path> with the path to libbfd.a on your system.):
$ CPPFLAGS=-I<hdr_path> LDFLAGS=-L<lib_path> ../configure --prefix=$PREFIX

Building and Installing under Windows

Building and installing the toolchain under Windows requires more effort because all of the tools required for building, and the programs themselves, are mainly designed for running under a POSIX environment such as Unix and Linux. Windows does not natively provide such an environment.

There are two projects available that provide such an environment, Cygwin and MinGW. There are advantages and disadvantages to both. Cygwin provides a very complete POSIX environment that allows one to build many Linux based tools from source with very little or no source modifications. However, POSIX functionality is provided in the form of a DLL that is linked to the application. This DLL has to be redistributed with your application and there are issues if the Cygwin DLL already exists on the installation system and different versions of the DLL. On the other hand, MinGW can compile code as native Win32 applications. However, this means that programs designed for Unix and Linux (i.e. that use POSIX functionality) will not compile as MinGW does not provide that POSIX layer for you. Therefore most programs that compile on both types of host systems, usually must provide some sort of abstraction layer to allow an application to be built cross-platform.

MinGW does provide somewhat of a POSIX environment, called MSYS, that allows you to build Unix and Linux applications as they woud normally do, with a configure step and a make step. Cygwin also provides such an environment. This means that building the AVR toolchain is very similar to how it is built in Linux, described above. The main differences are in what the PATH environment variable gets set to, pathname differences, and the tools that are required to build the projects under Windows. We'll take a look at the tools next.

Tools Required for Building the Toolchain for Windows

These are the tools that are currently used to build an AVR tool chain. This list may change, either the version of the tools, or the tools themselves, as improvements are made.

Note
GMP, MPFR, and MPC are required to build GCC.
GMP is a prequisite for building MPFR. Build GMP first.
MPFR is a prerequisite for building MPC. Build MPFR second.
Note
Doxygen is required to build AVR-LibC documentation.
NetPBM is required to build graphics in the AVR-LibC documentation.
fig2dev is required to build graphics in the AVR-LibC documentation.
  • Install fig2dev
    • Version 3.2 patchlevel 5c
    • From WinFig 4.62: http://www.schmidt-web-berlin.de/winfig/
    • Download the zip file version of WinFig
    • Unzip the download file and install fig2dev.exe in a location of your choice, somewhere in the PATH.
    • You may have to unzip and install related DLL files for fig2dev. In the version above, you have to install QtCore4.dll and QtGui4.dll.
MikTeX is required to build various documentation.
Ghostscript is required to build various documentation.
  • Install Ghostscript
    • Version 9.00
    • http://www.ghostscript.com
    • Download and install.
    • In the \bin subdirectory of the installaion, copy gswin32c.exe to gs.exe.
  • Set the TEMP and TMP environment variables to c:\temp or to the short filename version. This helps to avoid NTVDM errors during building.

Building the Toolchain for Windows

All directories in the PATH enviornment variable should be specified using their short filename (8.3) version. This will also help to avoid NTVDM errors during building. These short filenames can be specific to each machine.

Build the tools below in MinGW/MSYS.

Build the tools below in Cygwin.