AsteriskCrossCompile

Script to allow cross compilation of Asterisk Build tested on Ubuntu 20.04.1

I recommend using crosstool-ng (https://crosstool-ng.github.io/) to generate your cross compiling toolchain and installing in the default directory $HOME/x-tools/$TARGETMACH/

This script assumes the cross compiling toolchain is installed under $HOME/x-tools/$TARGETMACH/

The script will also attempt to build the crosstool chain for you if it does not detect one

Variables

BUILDMACH = The architecture of the machine you are building on, almost always x86_64-pc-linux-gnu
TARGETMACH = The architecture of the machine you are building for, i.e. arm-cortex_a8-linux-gnueabihf
THREADS = Number of threads to use when compiling
SYSROOT = The location to "install" all the cross compiled libraries. Defaults to sysroot in the current directory
ASTERISK_INSTALLDIR = The location to install the cross compiled Asterisk. Defaults to asterisk in the current directory.
BUILDDIR = The location to stage the build. Defaults to build in the current directory

MESON_* variables are for the Meson build system required for glib2. Please see the Meson page for help setting these.

The current compiler flags below have been optimised for the Beagle Bone Black, if you have another processer please remove the optimisations.

GLOBAL_CFLAGS = C compiler flags used to make every binary (except crosstools-ng)
GLOBAL_CXXFLAGS = C++ compiler flags used to make every binary (except crosstools-ng)
GLOBAL_CPPFLAGS = C preprocessor flags used to make every binary (except crosstools-ng)
GLOBAL_LDFLAGS = Linker options used to make every binary (except crosstools-ng)

Likewise, the build toolchain step at line 105 also has Beagle Bone Black optimisations, remove as required.

Usage

You have two options, install the dependencies of Asterisk on the target from the target's package manager or use the cross compiled versions.

Using Target Package Manager

1. Install the Asterisk Dependencies on the target

SSH/Console in and install ZLib, Jansson, LibEdit, LibXSLT, LibXML2, LibSRTP, SQLite, OpenSSL, LibUUID, BluEZ (bluetooth) Note: Some packages may be preinstalled on certain distributions

i.e. for ArchLinux

pacman -Syu jansson libedit libxslt libxml2 libsrtp openssl bluez

2. Make note of the versions of these libraries, as we will have to download the same versions to compile against on the host machine. Note: The versions of libuuid and SQLite appear not to be so strict in matching

3. On your host machine, modify the SOURCE URLS section of the script to download the same versions of the libraries you just installed on the target

4. Execute the script on the host

5. Enter ${ASTERISKINSTALLDIR} You will see the following folders

etc/
include/
lib/
sbin/
share/
var/

This is the base installation of Asterisk + Chan SCCP

6. Edit $ASTERISK_INSTALLDIR/etc/asterisk/asterisk.conf and modify based on where Asterisk will live on your target device:

[directories]
astetcdir => /etc/asterisk
astmoddir => /lib/asterisk/modules
astvarlibdir => /var/lib/asterisk
astdbdir => /var/lib/asterisk
astsbindir => /asterisk/sbin
astdatadir => /var/lib/asterisk
astspooldir => /var/spool/asterisk
astrundir => /var/run/asterisk
astkeydir => /var/lib/asterisk
astagidir => /var/lib/asterisk/agi-bin
astlogdir => /var/log/asterisk

7. Copy the contents of ${ASTERISK_INSTALLDIR} to the desired location on the target

8. Run sudo ldconfig -v to update the shared libraries (if you installed the asterisk libraries in a non-standard location you will have to add these to the shared linker paths by creating a file under /etc/ld.so.conf/myCustomLocation.conf and inserting the location of your custom libary directory before running the command)

9. Asterisk is now ready to run, specify the conf file using the -C parameter

asterisk -f -C /etc/asterisk/asterisk.conf

Using Compiled Versions

Skip steps 1 and 2 above, and in step 3 pick and choose the versions of libraries you want to use. Lastly after step 7, you will have to copy over the libraries to the target located in ${SYSROOT}

Re-compiling

You can remove directories from the $BUILDDIR, or the library from $SYSROOT to force the script to recompile that particular module. Note: It is not smart enough to work out compile dependencies if you update a single module. In this case I recommend wiping the whole $BUILDDIR and $SYSROOT directories to force compilation of everything. Similarly, deleting the $ASTERISK_INSTALLDIR will also force a compile of asterisk.