man cross-gcc-gensource (1): generates sources to build a Debian cross toolchain

SYNOPSIS

[TARGET_LIST=<arches to target>] [HOST_LIST=<build arches>] [SUFFIX=.1] cross-gcc-gensource <gcc-version>
example:
/tmp$ TARGET_LIST="armel armhf" HOST_LIST="amd64" cross-gcc-gensource 5
.... lots of verbose output ....
/tmp$ cd cross-gcc-packages-amd64/cross-gcc-5-armel
/tmp/cross-gcc-packages-amd64/cross-gcc-5-armel$ ls
debian
/tmp/cross-gcc-packages-amd64/cross-gcc-5-armel$ dpkg-buildpackage
.... building cross-toolchain ....

DESCRIPTION

This is a utility that prepares a directory with debianized sources which build cross toolchain packages. The sources produced by this tool are very small; the code itself comes from the "gcc-version-source" package and the necessary patches and extra build stuff comes from the "cross-gcc-dev" package.

ARGUMENTS

Normal usage is

 cross-gcc-gensource gcc_version

Where "gcc_version" is the base version of the toolchain we're building. At the time of this writing we know about versions 4.9, 5 and 6. This commandline argument is required.

Specifying the target architectures

This tool generates a separate source package for each target architecture (the architecture targetted by the cross-compiler being built). By default these architectures are targetted:

arm64
armel
armhf
mips
mipsel
powerpc
ppc64el

If a different set of target architectures is required, set the "TARGET_LIST" environment variable. For instance, to build for "armel" and "armhf":

 TARGET_LIST="armel armhf" cross-gcc-gensource 5

Specifying the host architectures

Similarly, this tool generates a separate source tree for each host architecture (the architecture the cross-compiler being built runs on). By default these architectures are targetted:

amd64
i386

If a different set of host architectures is required, set the "HOST_LIST" environment variable. For instance, to build just for "amd64":

 HOST_LIST="amd64" cross-gcc-gensource 5

Specifying a verison suffix

If you need to upload a new source package when the version of gcc-source built-against hasn't changed, then you need to add a version suffix to avoid binary-version clashes. An optional SUFFIX env var allows this.