Difference between revisions of "EBC Exercise 08 Installing Development Tools 3.8"

From eLinux.org
Jump to: navigation, search
m (Download and Compile U-boot: Added bitbake u-boot)
m (Changed)
 
(93 intermediate revisions by 11 users not shown)
Line 1: Line 1:
[[Category:ECE497]]
+
[[Category:ECE497Fall2014]]
 +
{{YoderHead}}
 +
{{EBC3.8}}See [[EBC Exercise 08 Installing Development Tools 3.2]] if you are working with the 3.2 kernel.
  
Early in the class most of the exercises we will do will all run on the BeagleBoard. You'll be able to edit ([http://projects.gnome.org/gedit/ gedit]), compile ([http://gcc.gnu.org/ gcc]) and run all on the Beagle.  Later, when we start compiling the kernel [http://www.kernel.org/] or the boot loader, ([http://www.denx.de/wiki/U-Boot U-boot]) you will need to cross compile on a Linux machine and copy the results to the Beagle.
+
Early in the class most of the exercises we will do will all run on the BeagleBoard. You'll be able to edit ([http://projects.gnome.org/gedit/ gedit]), compile ([http://gcc.gnu.org/ gcc]) and run all on the Beagle.  Later, when we start compiling the [http://www.kernel.org/ kernel] or the boot loader, ([http://www.denx.de/wiki/U-Boot 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.
 
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 [http://www.angstrom-distribution.org/building-angstrom here]; however there are a few changes you have to make.  Here's what I did.
+
Instructions for building Ångström are given [http://www.angstrom-distribution.org/building-angstrom here]; however there are a few changes you have to make.  Here's what I did.
  
== Install development environment ==
+
'''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.
  
The step is to get the crosscompilers, etc. installed.
+
== The 3.8 Kernel ==
 +
{{EBC3.8}}Make sure you installed the cross compiler ([[EBC Exercise 08a Cross-Compiling]]) before doing this exercise.
  
=== Get the setup scripts ===
+
=== Getting the 3.8 Kernel ===
  
First install <code>git</code> by running the following on your host computer.
+
These notes taken from [http://www.youtube.com/watch?v=HJ9nUqYMjqs&t=4m10s Beaglebone: Adding USB Wi-Fi & Building a Linux Kernel] starting around 4 minutes and ending around 21 minutes.  Uses kernel from [http://eewiki.net/display/linuxonarm/BeagleBone+Black Robert C. Nelson's BeagleBone Black] page.
<pre>
 
$ sudo apt-get install git-core
 
</pre>
 
(Here is a nice [http://progit.org/book/ git tutorial]. Take a look at it if you want to understand the commands that follow. We'll explore it in more depth in a later exercise.)
 
  
Then run the following to load the meta data.
+
host$ '''git clone git://github.com/RobertCNelson/linux-dev.git'''
 +
host$ '''cd linux-dev'''
 +
host$ '''git checkout origin/am33x-v3.8 -b am33x-v3.8'''
 +
host$ '''time git clone git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git'''  (21 minutes)
 +
host$ '''cp system.sh.sample system.sh'''
 +
Now make the following changes to '''system.sh'''.  The <code>></code> shows what's in system.sh.sample. The <code><</code> shows what you should change it to.
 +
host$ '''diff system.sh*'''
 +
15c15
 +
< CC=arm-linux-gnueabi-
 +
---
 +
> #CC=arm-linux-gnueabi-
 +
21c21
 +
< LINUX_GIT=~/BeagleBoard/linux-stable/
 +
---
 +
> #LINUX_GIT=/home/user/linux-stable/
 +
31c31
 +
< ZRELADDR=0x80008000
 +
---
 +
> #ZRELADDR=0x80008000
  
I have everything in a <code>~/BeagleBoard</code>, so here is how I setup things:
+
Now build the kernel.
<pre>
+
host$ '''./build_kernel.sh'''
$ cd
+
+ Detected build host [Ubuntu 14.04 LTS]
$ mkdir -p BeagleBoard
+
+ host: [x86_64]
$ cd BeagleBoard
+
+ git HEAD commit: [58ee2121370badd3c0a22e39f67068f242d5e068]
$ git clone git://git.angstrom-distribution.org/setup-scripts oe
+
Debian/Ubuntu/Mint: missing dependencies, please install:
$ cd oe
+
-----------------------------
</pre>
+
sudo apt-get update
(The git took 4.5 seconds.)
+
sudo apt-get install build-essential device-tree-compiler fakeroot lzma lzop u-boot-tools  libncurses5-dev:amd64 libc6:i386 libncurses5:i386 libstdc++6:i386 zlib1g:i386
This creates a directory for open embedded (<code>oe</code>) and gets the script to download Ångström. What files do you see?
+
-----------------------------
 +
  * Failed dependency check
  
=== Setting up for the BeagleBoard ===
+
The build script is telling you what you need to install.  Do the installs and rerun the build command.
 +
host$ '''./build_kernel.sh'''
 +
  + Detected build host [Ubuntu 12.04.2 LTS]
 +
  Debian/Ubuntu/Mint: missing dependicies, please install:
 +
  -----------------------------
 +
  sudo apt-get update
 +
  sudo apt-get install libncurses5-dev
 +
  -----------------------------
 +
  * Failed dependency check
 +
If you don't get this error, move to the next step. I fixed this error by editing <code>linux-dev/tools/host_det.sh</code> and commenting out the line:
 +
# dpkg -l | grep libncurses5-dev | grep ${deb_arch} >/dev/null || deb_pkgs="${deb_pkgs}libncurses5-dev "
 +
It was looking for amd64 in the <code>dpkg -l</code> listing and it wasn't appearing.
  
Now let's setup <code>local.conf</code> for our needs:
+
=== Building the 3.8 Kernel ===
$ gedit conf/local.conf
 
Add the following to the '''end''' of the file.
 
MACHINE ?= "beagleboard"
 
Look at this block of lines:
 
<pre>
 
# Make use of SMP and fast disks
 
PARALLEL_MAKE = "-j2"
 
BB_NUMBER_THREADS = "2"
 
</pre>
 
Here you can tell it how many parallel threads to run.  If you have several cores on your machine, make this number big.  If you have only one core, you might be better performance setting it to 1. If you have no clue which value to pick, Gentoo users suggest 1 more than the number of cores in your computer. More details are [http://wiki.openembedded.org/index.php/Advanced_configuration here].
 
* PARALLEL_MAKE sets the number "gcc" threads (same as make -j4 at compile time
 
* BB_NUMBER_THREADS sets the number of bitbake threads, (one thread can be downloading, while another compiles)
 
  
To save you a lot of time, it is useful to disable locale generation for all but the one you need. Add this to local.conf
+
Rerun the kernel build
GLIBC_GENERATE_LOCALES = "en_US.UTF-8 en_GB.UTF-8 de_DE.UTF-8 fr_FR.UTF-8 pt_BR.UTF-8 es_ES.UTF-8 kn_IN.UTF-8 ml_IN.UTF-8 ta_IN.UTF-8"
+
host$ '''./build_kernel.sh'''
 +
At some point you will see
 +
[[File:KernelConfiguration.png]]
 +
[http://www.youtube.com/watch?v=HJ9nUqYMjqs&t=13m30s Go back to the video above and forward to 13:30]. Here you will see how to configure the kernel. Once you've exited the configuration tool the kernel will start compiling. If you have a multicore machine you will see all the cores busy. It's only a few more minutes before it is done.
  
Now run:
+
=== Installing the 3.8 Kernel on Your Black Bone ===
<pre>
 
$ ./oebb.sh config beagleboard
 
$ ./oebb.sh update
 
</pre>
 
This will bring in all the tools you need.  The config took about 3.5 minutes on my machine, update took about 1 minute.
 
  
=== Build a small program ===
+
==== Updating and running off the eMMC ====
 +
[[EBC_Exercise_23_Configuring_the_Kernel#Making_and_Installing_the_kernel]] has instructions for copying the correct files to the eMMC to update the kernel.
  
Before the first time you run bitbake you need to do the following to set up the environmental variables:
+
==== Booting off the SD card ====
$ source ~/.oe/environment-oecore
+
Here are some '''optional''' instructions for booting off the SD card rather than the eMMC.
  
Take a look in the file and see what it is doing.
+
So far you'be been running everything off the onboard 2G flash. You can continue to do so, but when installing a new kernel there is a good chance you mess up your image and it will be another 45 minutes to reflash itInstead go back to [[EBC_Exercise_03_Installing_a_Beagle_OS]] an instead of installing the eMMC flasher image from [http://beagleboard.org/latest-images], install the '''BeagleBone (Runs on BeagleBone Black as well without flashing the eMMC)''' image (first list). 
  $ less ~/.oe/environment-oecore
 
  
To see if everything is ready, run the following
+
This time when you plug in the SD and boot the bone will boot from the SD card (rather than copying a new image to the 2G builting flash).  I suggest programming 2 or 3 SD cards with this image.  That way if you really mess up one you can always switch to a another card and keep going.
  
$ bitbake nano
+
Also, if you are booting from the SD and mess up something, you can plug the messed up card into your host computer and fix things and try it again.
  
nano is a small editor.  We really don't need nano, but if it can be compiled we know we have everything in place.  I get the following error when I run the bitbake:
+
==== Copying to the SD Card ====
<pre>
+
Now install by inserting the SD to be installed on into your host machine and run:
Pseudo is not present but is required, building this first before the main build
+
  host$ ./tools/install_kernel.sh
.
 
.
 
.
 
ERROR: Poky's config sanity checker detected a potential misconfiguration.
 
    Either fix the cause of this error or at your own risk disable the checker (see sanity.conf).
 
    Following is the list of potential problems / advisories:
 
  
    Please install following missing utilities: C++ Compiler (g++),diffstat,texi2html,makeinfo,cvs,svn,chrpath
+
Mine failed because there wasn't enough space on the VFAT partition for uImage, however uImage isn't needed there, so I just editted <code>install_kernel.sh</code> and commented out line '''160'''
 +
# mmc_partition_discover
 +
This keeps it from installing on the VFAT partition.
  
ERROR: Execution of event handler 'check_sanity_eventhandler' failed
+
=== Updating to a new version of the kernel ===
</pre>
 
So, some programs are missing.  Install them with:
 
$ sudo apt-get install g++ diffstat texi2html texinfo cvs subversion chrpath help2man diffstat texi2html cvs texinfo subversion gawk
 
This took just a few minutes.
 
  
Now run:
+
When you build your kernel the uImage file has some version information in the name.  For example '''uImage-3.8.13-bone20'''. The '''3.8.13''' is the version of the kernel and the '''bone20''' is the version of the patches applied to the kernel for the BeagleBoneOver time new patches will be posted. These instructions show how to get the latest version.
  $ bitbake nano
 
This will take a while. Mine first said it has 77 tasks to doOnce those were done it had 1113 tasks.
 
  
Below is a table of the times from last year. Add your bitbake time to this year's table.
+
How do you know if you have the latest version?  Run
{| style="color:green; background-color:#ffffcc;" cellspacing="0" border="1" cellpadding="5"
+
beagle$ '''uname -a'''
|+ Initial <tt>bitbake nano</tt> Winter 2011-2012 runtimes
+
  Linux yoder-black-bone '''3.8.13-bone28''' #1 SMP Wed Oct 16 15:32:18 EDT 2013 armv7l GNU/Linux
! Processor
+
to see what version you are running. [http://rcn-ee.net/deb/precise-armhf/ This site lists many different versions].  See if yours is the newest, if not continue on.
! Settings
 
! Run Time
 
|-
 
| 8 Core virtual machine
 
| PARALLEL_MAKE = "-j8"<br>BB_NUMBER_THREADS = "8"<br>
 
| 2.5 hours
 
  
|}
+
This [https://groups.google.com/forum/#!topic/beagleboard/D3wRnulVE1I post to the Google Group] lists the steps as "You need to recheckout master, delete your old branch and re-pull". Here's how you do it.
{| border="1" cellspacing="0" cellpadding="5"
 
|+ Initial <tt>bitbake nano</tt> 2011 runtimes
 
! Processor
 
! Settings
 
! Run Time
 
|-
 
| Dell E521 with AMD Athlon 64 dual-core
 
| PARALLEL_MAKE = "-j4"<br>BB_NUMBER_THREADS = "4"<br>Psyco? Yes.
 
| 1.5 hours
 
|-
 
| Intel Core 2 Duo T7800, 2.60 GHz
 
| PARALLEL_MAKE = "-j1"<br>BB_NUMBER_THREADS = "1"<br>Psyco? No.
 
| 1:46
 
|-
 
| Intel Core 2 Duo T7800, 2.60 GHz
 
| PARALLEL_MAKE = "-j4"<br />BB_NUMBER_THREADS = "3"<br />Psyco? Yes.<br />Ubuntu 10.04 Running in VMWare Workstation 7.1.3 Under Windows 7 32-bit
 
| 1:42
 
|}
 
  
Once nano is done building you can find it with:
+
host$ '''cd linux-dev'''
  $ find . -name nano
+
host$ '''git checkout master'''
Can you figure out which one is the nano that will run on your Beagle?
+
error: Your local changes to the following files would be overwritten by checkout:
 +
patches/defconfig
 +
Please, commit your changes or stash them before you can switch branches.
 +
Aborting
 +
Hmm.... something has changed.  See what it is.
 +
  host$ '''git diff patches/defconfig'''
 +
diff --git a/patches/defconfig b/patches/defconfig
 +
index d903776..3268287 100644
 +
--- a/patches/defconfig
 +
+++ b/patches/defconfig
 +
@@ -2041,6 +2041,7 @@ CONFIG_JHD629_I2C=y
 +
  # CONFIG_SERIAL_NONSTANDARD is not set
 +
  # CONFIG_N_GSM is not set
 +
  # CONFIG_TRACE_SINK is not set
 +
+CONFIG_LPD8806=m
 +
  CONFIG_DEVKMEM=y
 +
 
 +
  #
 +
It looks like some configuration setting have changed.  Since we are getting a new version of the kernel, let's revert back to the previous file and try again.
  
== Download and Compile the Kernel ==
+
host$ '''git checkout patches/defconfig'''
 +
host$ '''git checkout master'''
 +
Switched to branch 'master'
 +
Success, now step 2.
 +
host$ '''git branch -d am33x-v3.8'''
 +
warning: deleting branch 'am33x-v3.8' that has been merged to
 +
          'refs/remotes/origin/am33x-v3.8', but not yet merged to HEAD.
 +
Deleted branch am33x-v3.8 (was 3fc8a73).
 +
Now repull
 +
host$ '''git pull'''
 +
Then start over again
 +
host$ '''git checkout origin/am33x-v3.8 -b am33x-v3.8'''
 +
Branch am33x-v3.8 set up to track remote branch am33x-v3.8 from origin.
 +
Switched to a new branch 'am33x-v3.8'
 +
Your '''system.sh''' file should be unchanged, so start building
 +
host$ '''./build_kernel.sh'''
 +
Mine took some 26 minutes on an 8 core machine.
  
The next step is to download and compile the kernel.
+
== DAS U-boot ==
 +
These instructions came from [http://www.eewiki.net/display/linuxonarm/BeagleBone+Black#BeagleBoneBlack-Bootloader Robert C Nelson's eewiki.net].
  
We want to keep the kernel source code around so we can experiment with it.  Do this:
+
=== download ===
$ gedit conf/local.conf
+
While we're at it, let's get the boot loader we'll be usingIt takes some 40 seconds.
Find the line near the '''top''' that says <code>INHERIT += " rm_work "</code> and comment it outThis will save the source code.
 
# INHERIT += " rm_work
 
  
Exit gedit and do the following:
+
host$ '''cd ~/BeagleBoard'''
<pre>
+
host$ '''git clone git://git.denx.de/u-boot.git'''
$ source ~/.oe/environment-oecore
+
host$ '''cd u-boot/'''
$ cd ~/BeagleBoard/oe
+
host$ '''git checkout v2013.07 -b tmp'''
$ bitbake virtual/kernel
 
</pre>
 
Mine says it has 1032 tasks to do.  It took about XX hours to do them.  Once done you should get a kernel that will work.
 
  
If you accidentally run bitbake without commenting out the above line, after it runs you can comment out the INHERIT line and then run
+
=== U-Boot Patches ===
<pre>
+
host$ '''wget https://raw.github.com/eewiki/u-boot-patches/master/v2013.07/0001-am335x_evm-uEnv.txt-bootz-n-fixes.patch'''
$ bitbake -c clean virtual/kernel
+
host$ '''patch -p1 < 0001-am335x_evm-uEnv.txt-bootz-n-fixes.patch'''
$ bitbake -f -c compile virtual/kernel
 
</pre>
 
This second run should take less time (one timing: first run took 3.5 hours; the recompiling took 25 minutes).
 
  
== Download and Compile U-boot ==
+
=== compile ===
 +
Now configure and build.  The first time takes some 1.5 minutes.  After that it's only 5 seconds or so.
 +
host$ '''source ~/crossCompileEnv.sh'''
 +
host$ '''make distclean'''
 +
host$ '''make am335x_evm_config'''
 +
host$ '''make'''
  
While were' at it, let's get the boot loader we'll be using...
+
=== install ===
  
  $ bitbake u-boot
+
  host$ '''scp u-boot.img root@beagle:.'''
 +
beagle$ '''mkdir /media/BONE'''
 +
beagle$ '''mount /dev/mmcblk0p1 /media/BONE'''
 +
beagle$ '''cd /media/BONE'''
 +
beagle$ '''mv u-boot.img u-boot.img.orig'''  # Save the working u-boot
 +
beagle$ '''cp ~/u-boot.img u-boot.img.new'''
 +
beagle$ '''cp u-boot.img.new u-boot.img'''
  
I think this took a half hour or so.
+
Once installed you are ready for u-boot work.
  
Once installed you are ready for kernel work.
+
== Recovering ==
 +
If your Beagle fails to boot, follow the [[EBC_Exercise_22_Recovering]] instructions to recover.
 +
 
 +
{{YoderFoot}}

Latest revision as of 06:01, 12 October 2016

thumb‎ Embedded Linux Class by Mark A. Yoder


3.8 Kernel

See EBC Exercise 08 Installing Development Tools 3.2 if you are working with the 3.2 kernel.

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 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.

The 3.8 Kernel

3.8 Kernel

Make sure you installed the cross compiler (EBC Exercise 08a Cross-Compiling) before doing this exercise.

Getting the 3.8 Kernel

These notes taken from Beaglebone: Adding USB Wi-Fi & Building a Linux Kernel starting around 4 minutes and ending around 21 minutes. Uses kernel from Robert C. Nelson's BeagleBone Black page.

host$ git clone git://github.com/RobertCNelson/linux-dev.git
host$ cd linux-dev
host$ git checkout origin/am33x-v3.8 -b am33x-v3.8
host$ time git clone git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git  (21 minutes)
host$ cp system.sh.sample system.sh

Now make the following changes to system.sh. The > shows what's in system.sh.sample. The < shows what you should change it to.

host$ diff system.sh*
15c15
< CC=arm-linux-gnueabi-
---
> #CC=arm-linux-gnueabi-
21c21
< LINUX_GIT=~/BeagleBoard/linux-stable/
---
> #LINUX_GIT=/home/user/linux-stable/
31c31
< ZRELADDR=0x80008000
---
> #ZRELADDR=0x80008000

Now build the kernel.

host$ ./build_kernel.sh
+ Detected build host [Ubuntu 14.04 LTS]
+ host: [x86_64]
+ git HEAD commit: [58ee2121370badd3c0a22e39f67068f242d5e068]
Debian/Ubuntu/Mint: missing dependencies, please install:
-----------------------------
sudo apt-get update
sudo apt-get install build-essential device-tree-compiler fakeroot lzma lzop u-boot-tools   libncurses5-dev:amd64 libc6:i386 libncurses5:i386 libstdc++6:i386 zlib1g:i386 
-----------------------------
* Failed dependency check

The build script is telling you what you need to install. Do the installs and rerun the build command.

host$ ./build_kernel.sh
 + Detected build host [Ubuntu 12.04.2 LTS]
 Debian/Ubuntu/Mint: missing dependicies, please install:
 -----------------------------
 sudo apt-get update
 sudo apt-get install libncurses5-dev 
 -----------------------------
 * Failed dependency check

If you don't get this error, move to the next step. I fixed this error by editing linux-dev/tools/host_det.sh and commenting out the line:

#	dpkg -l | grep libncurses5-dev | grep ${deb_arch} >/dev/null || deb_pkgs="${deb_pkgs}libncurses5-dev "

It was looking for amd64 in the dpkg -l listing and it wasn't appearing.

Building the 3.8 Kernel

Rerun the kernel build

host$ ./build_kernel.sh

At some point you will see KernelConfiguration.png Go back to the video above and forward to 13:30. Here you will see how to configure the kernel. Once you've exited the configuration tool the kernel will start compiling. If you have a multicore machine you will see all the cores busy. It's only a few more minutes before it is done.

Installing the 3.8 Kernel on Your Black Bone

Updating and running off the eMMC

EBC_Exercise_23_Configuring_the_Kernel#Making_and_Installing_the_kernel has instructions for copying the correct files to the eMMC to update the kernel.

Booting off the SD card

Here are some optional instructions for booting off the SD card rather than the eMMC.

So far you'be been running everything off the onboard 2G flash. You can continue to do so, but when installing a new kernel there is a good chance you mess up your image and it will be another 45 minutes to reflash it. Instead go back to EBC_Exercise_03_Installing_a_Beagle_OS an instead of installing the eMMC flasher image from [1], install the BeagleBone (Runs on BeagleBone Black as well without flashing the eMMC) image (first list).

This time when you plug in the SD and boot the bone will boot from the SD card (rather than copying a new image to the 2G builting flash). I suggest programming 2 or 3 SD cards with this image. That way if you really mess up one you can always switch to a another card and keep going.

Also, if you are booting from the SD and mess up something, you can plug the messed up card into your host computer and fix things and try it again.

Copying to the SD Card

Now install by inserting the SD to be installed on into your host machine and run:

host$ ./tools/install_kernel.sh

Mine failed because there wasn't enough space on the VFAT partition for uImage, however uImage isn't needed there, so I just editted install_kernel.sh and commented out line 160

#			mmc_partition_discover

This keeps it from installing on the VFAT partition.

Updating to a new version of the kernel

When you build your kernel the uImage file has some version information in the name. For example uImage-3.8.13-bone20. The 3.8.13 is the version of the kernel and the bone20 is the version of the patches applied to the kernel for the BeagleBone. Over time new patches will be posted. These instructions show how to get the latest version.

How do you know if you have the latest version? Run

beagle$ uname -a
Linux yoder-black-bone 3.8.13-bone28 #1 SMP Wed Oct 16 15:32:18 EDT 2013 armv7l GNU/Linux

to see what version you are running. This site lists many different versions. See if yours is the newest, if not continue on.

This post to the Google Group lists the steps as "You need to recheckout master, delete your old branch and re-pull". Here's how you do it.

host$ cd linux-dev
host$ git checkout master
error: Your local changes to the following files would be overwritten by checkout:
	patches/defconfig
Please, commit your changes or stash them before you can switch branches.
Aborting

Hmm.... something has changed. See what it is.

host$ git diff patches/defconfig
diff --git a/patches/defconfig b/patches/defconfig
index d903776..3268287 100644
--- a/patches/defconfig
+++ b/patches/defconfig
@@ -2041,6 +2041,7 @@ CONFIG_JHD629_I2C=y
 # CONFIG_SERIAL_NONSTANDARD is not set
 # CONFIG_N_GSM is not set
 # CONFIG_TRACE_SINK is not set
+CONFIG_LPD8806=m
 CONFIG_DEVKMEM=y
 
 #

It looks like some configuration setting have changed. Since we are getting a new version of the kernel, let's revert back to the previous file and try again.

host$ git checkout patches/defconfig
host$ git checkout master
Switched to branch 'master'

Success, now step 2.

host$ git branch -d am33x-v3.8
warning: deleting branch 'am33x-v3.8' that has been merged to
         'refs/remotes/origin/am33x-v3.8', but not yet merged to HEAD.
Deleted branch am33x-v3.8 (was 3fc8a73).

Now repull

host$ git pull

Then start over again

host$ git checkout origin/am33x-v3.8 -b am33x-v3.8
Branch am33x-v3.8 set up to track remote branch am33x-v3.8 from origin.
Switched to a new branch 'am33x-v3.8'

Your system.sh file should be unchanged, so start building

host$ ./build_kernel.sh

Mine took some 26 minutes on an 8 core machine.

DAS U-boot

These instructions came from Robert C Nelson's eewiki.net.

download

While we're at it, let's get the boot loader we'll be using. It takes some 40 seconds.

host$ cd ~/BeagleBoard
host$ git clone git://git.denx.de/u-boot.git
host$ cd u-boot/
host$ git checkout v2013.07 -b tmp

U-Boot Patches

host$ wget https://raw.github.com/eewiki/u-boot-patches/master/v2013.07/0001-am335x_evm-uEnv.txt-bootz-n-fixes.patch
host$ patch -p1 < 0001-am335x_evm-uEnv.txt-bootz-n-fixes.patch

compile

Now configure and build. The first time takes some 1.5 minutes. After that it's only 5 seconds or so.

host$ source ~/crossCompileEnv.sh 
host$ make distclean
host$ make am335x_evm_config
host$ make

install

host$ scp u-boot.img root@beagle:.
beagle$ mkdir /media/BONE
beagle$ mount /dev/mmcblk0p1 /media/BONE
beagle$ cd /media/BONE
beagle$ mv u-boot.img u-boot.img.orig  # Save the working u-boot
beagle$ cp ~/u-boot.img u-boot.img.new
beagle$ cp u-boot.img.new u-boot.img

Once installed you are ready for u-boot work.

Recovering

If your Beagle fails to boot, follow the EBC_Exercise_22_Recovering instructions to recover.




thumb‎ Embedded Linux Class by Mark A. Yoder