EBC Exercise 27 BusyBox

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Revision as of 06:04, 22 October 2012 by Yoder (Talk | contribs) (Compiling BusyBox)

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thumb‎ Embedded Linux Class by Mark A. Yoder

Downloading and Compiling BusyBox

Get the busybox sources from the busybox site

host$ git clone git://busybox.net/busybox.git
host$ cd busybox
host$ source ~/.oe/crossCompileEnv.sh
host$ make help
host$ make defconfig
host$ make -j9       # use -jX for X-1 cores

Configuring BusyBox

You can now configure BusyBox.

host$ make gconfig

After saving the configuration changes to update the .config file, it is a simple matter of running make.

host$ make -j9

My make took about 1.5 minutes to compile (25 seconds with make -j8!).

Copy it to your Beagle and test it out. Just typing busybox will tell you what commands it knows. Try some of them.

host$ scp busybox root@beagle:.
beagle$ busybox
beagle$ busybox ls

Try some other commands...

Shrinking BusyBox

How big is the busybox file? Try making it smaller by removing commands you don't use. How big is it if you just have ls? How much bigger is it when you add httpd? Try your own combinations. Report your findings to the class.

Static Linking

Some embedded systems are so small they don't have shared libraries. Recompile busybox to be statically linked. (Hint: look in configuration) How big it is? Does it still work?

Running a Web Server

Configure busybox to be a web server. Look under Networking Untilites, select httpd. How much more space does it take?

beagle$ busybox httpd

Yup, you are now running a web server. Your task is to figure out where to put the web pages it is serving. If you get something interesting going post your Beagle's address here. Hint: find httpd.c.

URL Name Notes Mark A. Yoder My first Beagle web page.

thumb‎ Embedded Linux Class by Mark A. Yoder