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BeagleBone Cookbook by Jason Kridner, Mark A. Yoder

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Chapter 7. The Kernel

Introduction

The kernel is the heart of the Linux operating system. It’s the software that takes the low-level requests such as reading or writing files, or reading and writing GPIO pins, and maps them to the hardware. When you install a new version of the OS (Verifying You Have the Latest Version of the OS on Your Bone) you get a certain version of the kernel.

You usually won’t need to mess with the kernel, but sometimes you might want to try something new that requires a different kernel. This chapter shows how to switch kernels. The nice thing is you can have multiple kernels on your system at a time and select which one to boot from.

Note

We assume here that you are logged onto your Bone as root and and superuser privileges. You are also logged onto your Linux host computer as a non-superuser.

Updating the Kernel

Problem

You have an out-of-date kernel and want to want to make it current.

Solution

The following command will tell you which kernel you are running:

bone# uname -a
Linux beaglebone 3.8.13-bone67 #1 SMP Wed Sep 24 21:30:03 UTC 2014 armv7l GNU/Linux

The 3.8.13-bone67 string is the kernel version.

To update to the current kernel, make sure your Bone is on the Internet (Sharing the Host’s Internet Connection Over USB or Establishing an Ethernet-Based Internet Connection) and then run the following commands:

bone# apt-cache pkgnames | grep linux-image | sort | less ... linux-image-3.15.8-armv7-x5 linux-image-3.15.8-bone5 linux-image-3.15.8-bone6 ... linux-image-3.16.0-rc7-bone1 ...

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