Telecnatron Forum

A quick-start guide to getting a cross compilation environment up and running on Ubuntu Linux.

Hi, Thanks for really helpful and insightful information. I have been trying to cross compile Bluez 5.37 on OpenWRT platform using toolchain-arm_cortex-a7_gcc-5.2.0_uClibc-1.0.14_eabi. I have successfully compiled and executed bluetoothctl, hcitool, hcidump, rfcomm and various other programs using Makefile configurations. However, I am facing issue while compiling the agent program present in client directory(https://github.com/Vudentz/BlueZ/tree/master/client). The agent functionality is useful for auto pairing and connecting without any interruption from OpenWRT system. Can you please help me with the options in bluez makefile (https://github.com/openwrt/packages/blob/8d07e5b8252fb5b9b4c954a4cad169ab10c9e82c/utils/bluez/Makefile) for generating the agent executable. Thanks in advance for the information.

I think I've followed your instructions. I have no problem creating a helloworld for a router and having it run on the router. When I try to run a Makefile, objects get created but the linker returns: error adding symbols: File in wrong format for each object. What should I look at?

Thank you.

Thanks! I found it helpful. Zdenek

I am wondering why I always get a 'Segmentation Fault' when I run the compiled file on the router?

Hello, I am having a little problem cross-compiling a library called dns_sd which is part of avahi, can I reach you by email? I could pay you a little bit if you are able

Cross-compiling for OpenWRT on Linux allows you to build software that runs on OpenWRT routers using a development environment on your Linux machine. Here’s a straightforward guide to get you started:

Setting Up Your Environment
Install Required Tools:

First, ensure you have a Linux development environment set up. Common distributions like Ubuntu, Debian, or CentOS work well.
Install essential development tools:
sudo apt update
sudo apt install build-essential git
Install the cross-compilation toolchain for OpenWRT. This can vary depending on your router architecture. For example, for MIPS architecture:
sudo apt install gcc-mips-linux-gnu binutils-mips-linux-gnu
Adjust the package names based on your router's architecture (e.g., ARM, MIPS).
Download OpenWRT SDK:

Go to the OpenWRT downloads page and find the SDK for your router’s version and architecture. Download and extract it to your preferred directory:
wget [downloads.openwrt.org]
tar -xvf openwrt-sdk-xx.xx.xx-your_arch_gcc-xx.x.x_xxx.tar.xz
Building Your Application
Prepare Your Application:

Navigate to the SDK directory and clone your application’s source code or create a new project directory.
Place your application code inside the package directory within the SDK or create a Makefile if it’s not already provided.
Configure Your Build:

Enter the SDK directory and configure your build environment:
cd openwrt-sdk-xx.xx.xx-your_arch_gcc-xx.x.x_xxx
./scripts/feeds update -a
./scripts/feeds install your_package_name
Build Your Package:

Configure your package:

make menuconfig
Select your package under Utilities or Network category, depending on its purpose.

Build the package:

make package/your_package_name/compile V=s
Replace your_package_name with the actual name of your package.

Installing Your Package
Deploy to Your Router:
After a successful build, the compiled .ipk package file will be located in bin/packages/your_arch/packages/.
Transfer the .ipk file to your OpenWRT router (via SCP, USB, etc.).
Install the package on the router:
opkg install your_package_name.ipk
Notes
Dependencies: Ensure any dependencies required by your application are also available in the OpenWRT environment or included in your package build.
Testing: Test your application thoroughly on the target OpenWRT device to ensure compatibility and functionality.
By following these steps, you can effectively cross-compile applications for OpenWRT on your Linux machine, leveraging the flexibility and power of a development environment familiar to you.