Tag: beginners

Embedded Linux offers a powerful and flexible platform for building custom devices — from routers and industrial controllers to smart home appliances. But working in this space comes with unique challenges that aren’t always obvious to newcomers.

If you’re getting started with Embedded Linux development, here are some common (but avoidable) mistakes that could cost you time, performance, or even product stability.

1. Ignoring Kernel Configuration

Many developers use default kernel configurations without customizing it for their hardware.

Mistake:

• Leaving unnecessary drivers or debug options enabled.
• Missing critical hardware support for your board (e.g., SPI, I2C, GPIO).

Fix:

• Use make menuconfig (or xconfig) to tailor the kernel.
• Disable what you don’t need — it reduces size and boot time.

2. Bloated Root Filesystem

It’s tempting to include everything in the root filesystem during development.

Mistake:

• Shipping the same bloated image to production.
• Keeping tools like gcc, gdb, or even nano in the final image.

Fix:

• Use tools like Buildroot or Yocto to create minimal production images.
• Separate your debug image and production image builds.

3. Not Using a Proper Bootloader Setup

The bootloader (usually U-Boot) is critical in embedded systems.

Mistake:

• Ignoring U-Boot configuration.
• Not backing up working bootloader settings.

Fix:

• Learn the basics of U-Boot commands and environment variables.
• Save a backup of known-good U-Boot config (printenv, saveenv).

4. Skipping Logging and Monitoring

Without logs, debugging in Embedded Linux is like flying blind.

Mistake:

• Not enabling kernel logging (dmesg).
• Not using syslog or logread.

Fix:

• Configure lightweight loggers like BusyBox syslog or logrotate.
• For advanced use: forward logs over UART or remote via netconsole.

5. Overlooking Security Best Practices

Security is often an afterthought — but embedded devices are always connected these days.

Mistake:

• Using default root passwords.
• Leaving services like SSH open to all interfaces.

Fix:

• Disable unused services.
• Use read-only filesystems and non-root users for applications.
• Regularly update busybox/uClibc/libc and other core packages.

4. Lack of Version Control for Config and Build Scripts

You might be using Git for source code, but what about your build scripts, kernel configs, and environment setup?

Mistake:

• Manually modifying files without version tracking.

Fix:

• Keep your entire build system — including .config files and device trees — under Git.
• Document custom patches and build steps clearly.

7. Not Testing on Actual Hardware Early

Simulation or QEMU is good for prototyping, but it hides real-world problems.

Mistake:

• Developing purely on host or emulator.
• Postponing hardware testing until late.

Fix:

• Flash and test often on real hardware.
• Watch out for hardware timing issues, I/O race conditions, or thermal problems.

Final Thoughts

Embedded Linux gives you immense control, but also demands discipline. Avoiding these common mistakes can help you build stable, secure, and maintainable systems.

Take time to set up your environment correctly, document as you go, and always test on real hardware.

If you’re working on your first project, bookmark this list — it might just save you days of debugging later!

If you’re starting out with Embedded Linux, mastering a few essential commands can make your development and debugging process much easier. Whether you’re working on a Raspberry Pi, BeagleBone, or a custom ARM board, these Linux commands help you peek under the hood and interact with the system confidently.

In this post, we’ll walk through 5 must-know Linux commands every embedded developer should know — with simple, practical examples.

1. dmesg – View Kernel Messages

The dmesg command shows messages from the kernel ring buffer. It’s extremely helpful for checking hardware initialization, driver logs, and boot issues.

USE CASE:

• Check if a USB device or driver was detected.
• Debug kernel boot sequence.

eXAMPLE:

$ dmesg | tail -20

Shows the last 20 kernel messages.

$ dmesg | grep tty

Lists serial ports (useful for debugging UART).

2. lsmod – List Loaded Kernel Modules

This command lists all currently loaded kernel modules (drivers). It’s useful for verifying if a driver for your hardware is active.

uSE CASE:

• Check if your Wi-Fi or SPI driver is loaded.
• Debug missing hardware functionality.

eXAMPLE:

$ lsmod

You might see something like:

spi_bcm2835    16384  0

Which means the SPI driver is loaded on a device.

3. top – Monitor CPU and Memory Usage

top gives you a live, real-time view of processes and resource usage. It’s perfect for tracking down performance issues in embedded systems.

Use case:

• Identify CPU-heavy processes.
• Check RAM usage on limited-resource systems.

example:

$ top

Press q to quit. Press Shift + M to sort by memory usage.

4. free – Show Memory Usage Summary

While top is interactive, free gives a quick snapshot of memory usage, which is useful for embedded systems with limited RAM.

Use case:

• Monitor memory usage in scripts.
• Check for memory leaks or insufficient RAM.

example:

$ free -h

The -h flag shows memory in a human-readable format like MB or GB.

5. strace – Trace System Calls

strace helps you see what a program is doing behind the scenes by tracing system calls. It’s invaluable when debugging file access errors or unexpected behavior in embedded applications.

Use case:

• See if your application is trying to open a missing file.
• Trace execution of a malfunctioning process.

example:

$ strace ./my_app

You’ll see logs like:

open("/etc/myconfig.conf", O_RDONLY) = -1 ENOENT (No such file or directory)

That’s a clue that the app is looking for a config file that doesn’t exist!

Nice is it ?!

As an embedded developer, your job doesn’t stop at writing C/C++ code. You also need to understand how your software behaves in a Linux environment. These commands are like your first-aid toolkit — helping you debug, optimize, and understand the system better.

If you’re new, start by running these commands on your development board. Observe how they behave, and make them part of your daily routine.

Happy hacking!