Jessie armhf Cross Compile

Debian Jessie provides cross compilers, but it does require a Debian Jessie system to be used for the workstation. A PC, virtual machine, or chroot will need to be used for this. Download and install Debian Jessie for your workstation here.

From a Debian workstation (not the target), run these commands to set up the cross compiler:

# Run "lsb_release -a" and verify Debian 8.X is returned.  These instructions are not
# expected to work on any other version or distribution.

apt-get install curl build-essential

su root
echo "deb http://emdebian.org/tools/debian jessie main" > /etc/apt/sources.list.d/emdebian.list
curl http://emdebian.org/tools/debian/emdebian-toolchain-archive.key | apt-key add -
dpkg --add-architecture armhf
apt-get update
apt-get install crossbuild-essential-armhf

This will install a toolchain that can be used with the prefix "arm-linux-gnueabihf-". All of the standard GCC tools will start with that name, eg "arm-linux-gnueabihf-gcc".

The toolchain can now compile a simple hello world application. Create hello-world.c on the Debian workstation:

#include <stdio.h>
int main(){
    printf("Hello World\n");
}

To compile this:

arm-linux-gnueabihf-gcc hello-world.c -o hello-world
file hello-world

This will return that the binary created is for ARM. Copy this to the target platform to run it there.

Linking to a shared library from the Debian environment. Make sure the package that is being linked to is installed on both the Debian workstation and the target platform. Since armhf architecture support was added previously, it is now possible install armhf packages on the Debian workstation.

apt-get install libcurl4-openssl-dev:armhf

# Download the simple.c example from curl:
wget https://raw.githubusercontent.com/bagder/curl/master/docs/examples/simple.c
# After installing the supporting library, curl will link just as compiling on the unit.
arm-linux-gnueabihf-gcc simple.c -o simple -lcurl

The binary can now be copied over to the target platform and executed using the curl library that will be loaded at runtime from the target.

If any created binaries do not rely on hardware support like GPIO or CAN, they can be run using qemu.

# using the hello world example from before:
./hello-world
# Returns Exec format error
apt-get install qemu-user-static
./hello-world