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EBC Exercise 08 Installing Development Tools

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thumb‎ Embedded Linux Class by Mark A. Yoder


Early in the class most of the exercises we will do will all run on the BeagleBoard. You'll be able to edit (gedit), compile (gcc) and run all on the Beagle. Later, when we start compiling the kernel [1] or the boot loader, (U-boot) you will need to cross compile on a Linux machine and copy the results to the Beagle.

The purpose of this exercise is to install all the tools needed for compiling on your host so they will be ready when you need them.

Instructions for building Ångström are given here; however there are a few changes you have to make. Here's what I did.

Tip: Run this exercise using a wired connection if you can. The Ubuntu wireless driver can be finicky, and if it stops working you'll have to restart some of this.

Install development environment v2

Follow these v2 instructions. They work for the 3.2.25 kernel.

Using Jason's instructions

These are notes on following instructions Beagleboard kernel git site.

host$ sudo apt-get install -y git lzop gcc-arm-linux-gnueabi uboot-mkimage

25 seconds

host$ git clone git://github.com/beagleboard/kernel.git

2.5 seconds

host$ ./patch.sh

38.5 minutes

host$ make -j9

4 minutes

host$ make uImage

18 seconds

host$ make uImage
host$ mkdir ~/kernel/rootfs
host$ make INSTALL_MOD_PATH=~/kernel/rootfs modules_install
host$ cd

12 seconds

host$ scp kernel/kernel/arch/arm/boot/uImage root@beaglebone.local:/boot/uImage-3.2.25+

10 seconds

host$ cd kernel/rootfs
host$ find -H -depth | cpio -o -H crc | ssh root@beaglebone.local 'cd /; cpio -id' 

1 minute 16 seconds

host$ cd
host$ ssh root@beaglebone.local 'cd /boot; rm uImage' 
host$ ssh root@beaglebone.local 'cd /boot; ln -s uImage-3.2.25+ uImage'
host$ ssh root@beaglebone.local 'mount /dev/mmcblk0p1 /mnt'
host$ ssh root@beaglebone.local 'cp /boot/uImage-3.2.25+ /mnt/uImage'

Download and Compile U-boot

While were' at it, let's get the boot loader we'll be using...

host$ bitbake u-boot

Mine took about 8 minutes.

Once installed you are ready for kernel work.

Installing on a Remote Machine

Installing the cross development tools and the kernel on a laptop is nice, but sometimes the downloads are too long for such a portable device. I've had a bitbake run some 12 hours. Another option is to use a remote machine. In my case our CSSE department has created a virtual machine with Ubuntu 12.04 installed on it.

To install on a remote machine are the same as above; However here's a couple of tips to make it easier.

First, ssh to the remote machine. Assume the machine is called csse and your login name is beagle.

local$ ssh -CX beagle@csse

You can leave the beagle@ off if you have the same login on both machine. The -C says to compress everything that's moved between the machines over the network. This is good for slow connections. The X says to pass the X11 display information to the remote machine. This way you can run graphical programs, such as gedit, on the remote machine and the graphics will display on your local machine (assuming you are running X11 on your local machine).

If you are sshing a lot check out the tip here about suspending ssh and the tip here about authorizing ssh so you don't have to enter your password every time.

Once logged on to the removed machine run

remote$ sudo apt-get install byobu

This installs byobu which is a program that lets you connect to the same shell from multiple machines. Once installed run

remote$ byobu

You'll see something like:

Screenshot-beagle@ubu-may - byobu.png

So what? Run a couple of commands, like ls or who, then hit F6. This will suspend your session. Now run byobu again. You'll be back in the same session. The session keeps running, even when you aren't connected.

Do you see the use?

  • Fire up byobu
  • Start a long bitbake
  • Once you are sure it running OK, hit F6 and go home.
  • From home fire up byobu and you'll see your bitbake (probably still running).
  • You can F6 and check on it later.

Try opening another terminal and running byobu in both terminals. You'll see the same thing in both.

Run

$ man byobu

to see what it can do. Here's a list of shortcuts:

      F2 - Create a new window
      F3 - Move to previous window
      F4 - Move to next window
      F5 - Reload profile
      F6 - Detach from this session
      F7 - Enter copy/scrollback mode
      F8 - Re-title a window
      F9 - Configuration Menu
      F12 -  Lock this terminal
      Ctrl-a $ - show detailed status
      Ctrl-a R - Reload profile
      Ctrl-a ! - Toggle key bindings on and off
      Ctrl-a k - Kill the current window

But there is much more. Go and explore.




thumb‎ Embedded Linux Class by Mark A. Yoder