This is a Makefile that is supposed to build avr-gcc in a Native and/or a Canadian Cross configuration. A Canadian Cross Compiler is a compiler where Build, Host and Target systems are all different, with a layout something like: Build=x86_64-linux-gnu, Host=i686-w64-mingw32, Target=avr.

Examples

The build of a Canadian cross toolchain is as simple as

$ make install-w32

or

$ make -j44 JOBS=44 GCC_VERSION=8.5.1 install-w32

or for the the Native cross:

$ make -j44 JOBS=44 GCC_VERSION=8.5.1 install-native

When building a toolchain in several steps, make sure that you are using the same values of Makefile variables like GCC_VERSION as listed below.

Makefile Targets

Target	Action
[default]	Show a help screen
deps	Show (versions of) software that is required to build the Native cross toolchain.
deps-w32	Show (versions of) software that is required to build the Canadian cross toolchain.
all-native	Build a Native cross AVR toolchain, including downloading the sources as needed, but don't install.
install-native	Do all-native and install the resulting Native cross toolchain, minding all prerequisites. The install will be in folder ./install-native.
all-w32	Build a Canadian cross AVR toolchain for the HOST_W32 host, including downloading the sources, building and installing a Native cross toolchain as needed, but don't install the Canadian.
install-w32	Do all-w32 and install the resulting Canadian cross toolchain, minding all prerequisites. The install will be in folder ./install-w32.
deploy-native	Build a .tar.xz tarball from install-native including an ABOUT.txt.
deploy-w32	Build a .tar.xz tarball from install-w32 including an ABOUT.txt.

Makefile Variables

The script builds the tools from the GIT sources according to the TAG variables below, which specify the GIT branch or tag to use.

Variable	Default	Meaning
JOBS	1	Number of parallel make jobs.
HOST_W32	i686-w64-mingw32	Host OS for the Canadian cross
GCC_VERSION	15.1	GCC version
TAG_GCC	releases/gcc-$(GCC_VERSION).0 except for 8.5.1	git tag/branch for GCC
TAG_BIN	binutils-2_45	git tag/branch for Binutils
TAG_LIBC	main	git tag/branch for AVR-LibC
HTML	1	Include HTML documentation?
PDF	0	Include PDF documentation?
AVRDUDE_VERSION	8.1	Version of AVRDUDE to download and include in the Canadian cross tarball
CONF	—	Extra GCC Native cross configure args
CONF_W32	—	Extra GCC Canadian cross configure args
CONF_GCC	—	Extra GCC Native and Canadian config args
CONF_BIN	—	Extra Binutils Native and Canadian config args

Dependencies

First, it builds a Native Cross compiler (in blue). This is a Build→Target compiler, i.e. a compiler that runs on Build and generates code for Target. The dependency tree looks like this, where the graphs are understood as transitive:

This compiler is not contained in the Canadian distribution tarball, but it is required to build the Host→Target compiler (in red below). Apart from this compliler, two more toolchains must be available: A Build→Build compiler and a Build→Host cross compiler.

The dependency tree to build the Host→Target Canadian Cross looks like:

That is: The target libraries have already been built in the Native Cross step; all that needs to be done is installing them with the right prefix.