diff --git a/documentation/dev-manual/dev-manual-common-tasks.xml b/documentation/dev-manual/dev-manual-common-tasks.xml
index 824aac1236..918d884681 100644
--- a/documentation/dev-manual/dev-manual-common-tasks.xml
+++ b/documentation/dev-manual/dev-manual-common-tasks.xml
@@ -1352,6 +1352,8 @@
The easiest way to define kernel configurations is to set them through the
menuconfig tool.
+ This tool provides an interactive method with which
+ to set kernel configurations.
For general information on menuconfig, see
.
@@ -1359,6 +1361,9 @@
To use the menuconfig tool in the Yocto Project development
environment, you must build the tool using BitBake.
+ Thus, the environment must be set up using the &OE_INIT_FILE;
+ script found in the
+ Build Directory.
The following commands build and invoke menuconfig assuming the
source directory top-level folder is ~/poky:
@@ -1367,17 +1372,86 @@
$ bitbake linux-yocto -c menuconfig
Once menuconfig comes up, its standard interface allows you to
- examine and configure all the kernel configuration parameters.
- Once you have made your changes, simply exit the tool and save your changes to
+ interactively examine and configure all the kernel configuration parameters.
+ After making your changes, simply exit the tool and save your changes to
create an updated version of the .config configuration file.
- For an example that shows how to change a specific kernel option
- using menuconfig, see the
- "Changing
- the CONFIG_SMP Configuration Using menuconfig"
- section.
+ Consider an example that configures the linux-yocto-3.4
+ kernel.
+ The OpenEmbedded build system recognizes this kernel as
+ linux-yocto.
+ Thus, the following commands from the shell in which you previously sourced the
+ environment initialization script cleans the shared state cache and the
+ WORKDIR
+ directory and then builds and launches menuconfig:
+
+ $ bitbake linux-yocto -c menuconfig
+
+
+
+
+ Once menuconfig launches, you use the interface
+ to navigate through the selections to find the configuration settings in
+ which you are interested.
+ For example, consider the CONFIG_SMP configuration setting.
+ You can find it at Processor Type and Features under
+ the configuration selection Symmetric Multi-processing Support.
+ After highlighting the selection, you can use the arrow keys to select or deselect
+ the setting.
+ When you are finished with all your selections, exit out and save them.
+
+
+
+ Saving the selections updates the .config configuration file.
+ This is the file that the OpenEmbedded build system uses to configure the
+ kernel during the build.
+ You can find and examine this file in the build directory in
+ tmp/work/.
+ The actual .config is located in the area where the
+ specific kernel is built.
+ For example, if you were building a Linux Yocto kernel based on the
+ Linux 3.4 kernel and you were building a QEMU image targeted for
+ x86 architecture, the
+ .config file would be located here:
+
+ ~/poky/build/tmp/work/qemux86-poky-linux/linux-yocto-3.4.11+git1+84f...
+ ...656ed30-r1/linux-qemux86-standard-build
+
+
+ The previous example directory is artificially split and many of the characters
+ in the actual filename are omitted in order to make it more readable.
+ Also, depending on the kernel you are using, the exact pathname
+ for linux-yocto-3.4... might differ.
+
+
+
+
+ Within the .config file, you can see the kernel settings.
+ For example, the following entry shows that symmetric multi-processor support
+ is not set:
+
+ # CONFIG_SMP is not set
+
+
+
+
+ A good method to isolate changed configurations is to use a combination of the
+ menuconfig tool and simple shell commands.
+ Before changing configurations with menuconfig, copy the
+ existing .config and rename it to something else,
+ use menuconfig to make
+ as many changes an you want and save them, then compare the renamed configuration
+ file against the newly created file.
+ You can use the resulting differences as your base to create configuration fragments
+ to permanently save in your kernel layer.
+
+ Be sure to make a copy of the .config and don't just
+ rename it.
+ The build system needs an existing .config
+ from which to work.
+
diff --git a/documentation/dev-manual/dev-manual-kernel-appendix.xml b/documentation/dev-manual/dev-manual-kernel-appendix.xml
index 9070fcb561..6ea77d030c 100644
--- a/documentation/dev-manual/dev-manual-kernel-appendix.xml
+++ b/documentation/dev-manual/dev-manual-kernel-appendix.xml
@@ -546,299 +546,6 @@
-
-
- Changing the Kernel Configuration
-
-
- This example changes the default behavior, which is "on", of the Symmetric
- Multi-processing Support (CONFIG_SMP) to "off".
- It is a simple example that demonstrates how to reconfigure the kernel.
-
-
-
- Getting Set Up to Run this Example
-
-
- If you took the time to work through the example that modifies the kernel source code
- in "Modifying the Kernel Source
- Code" you should already have the Source Directory set up on your
- host machine.
- If this is the case, go to the next section, which is titled
- "Examining the Default
- CONFIG_SMP Behavior", and continue with the
- example.
-
-
-
- If you don't have the Source Directory established on your system,
- you can get them through tarball extraction or by
- cloning the poky Git repository.
- This example uses poky as the root directory of the
- Source Directory.
- See the bulleted item
- "Yocto Project Release"
- for information on how to get these files.
-
-
-
- Once you have the local copy of the repository set up,
- you have many development branches from which you can work.
- From inside the repository you can see the branch names and the tag names used
- in the upstream Git repository using either of the following commands:
-
- $ cd poky
- $ git branch -a
- $ git tag -l
-
- This example uses the Yocto Project &DISTRO; Release code named "&DISTRO_NAME;",
- which maps to the &DISTRO_NAME; branch in the repository.
- The following commands create and checkout the local &DISTRO_NAME;
- branch:
-
- $ git checkout -b &DISTRO_NAME; origin/&DISTRO_NAME;
- Branch &DISTRO_NAME; set up to track remote branch &DISTRO_NAME; from origin.
- Switched to a new branch '&DISTRO_NAME;'
-
-
-
-
- Next, you need to build the default qemux86 image that you
- can boot using QEMU.
-
- Because a full build can take hours, you should check two variables in the
- build directory that is created after you source the
- &OE_INIT_FILE; script.
- You can find these variables
- BB_NUMBER_THREADS and PARALLEL_MAKE
- in the build/conf directory in the
- local.conf configuration file.
- By default, these variables are commented out.
- If your host development system supports multi-core and multi-thread capabilities,
- you can uncomment these statements and set the variables to significantly shorten
- the full build time.
- As a guideline, set both the BB_NUMBER_THREADS and the
- PARALLEL_MAKE variables to twice the number
- of cores your machine supports.
-
- The following two commands source the build environment setup script
- and build the default qemux86 image.
- If necessary, the script creates the build directory:
-
- $ cd ~/poky
- $ source &OE_INIT_FILE;
-
- ### Shell environment set up for builds. ###
-
- You can now run 'bitbake <target>'
-
- Common targets are:
- core-image-minimal
- core-image-sato
- meta-toolchain
- meta-toolchain-sdk
- adt-installer
- meta-ide-support
-
- You can also run generated qemu images with a command like 'runqemu qemux86'
-
-
-
-
- The following bitbake command starts the build:
-
- $ bitbake -k core-image-minimal
-
- Be sure to check the settings in the local.conf
- before starting the build.
-
-
-
-
- Examining the Default <filename>CONFIG_SMP</filename> Behavior
-
-
- By default, CONFIG_SMP supports multiple processor machines.
- To see this default setting from within the QEMU emulator, boot your image using
- the emulator as follows:
-
- $ runqemu qemux86 qemuparams="-smp 4"
-
-
-
-
- Login to the machine using root with no password.
- After logging in, enter the following command to see how many processors are
- being supported in the emulator.
- The emulator reports support for the number of processors you specified using
- the -smp option, four in this case:
-
- # cat /proc/cpuinfo | grep processor
- processor : 0
- processor : 1
- processor : 2
- processor : 3
- #
-
- To check the setting for CONFIG_SMP, you can use the
- following command:
-
- zcat /proc/config.gz | grep CONFIG_SMP
-
- The console returns the following showing that multi-processor machine support
- is set:
-
- CONFIG_SMP=y
-
- Logout of the emulator using the exit command and
- then close it down.
-
-
-
-
- Changing the <filename>CONFIG_SMP</filename> Configuration Using <filename>menuconfig</filename>
-
-
- The menuconfig tool provides an interactive method with which
- to set kernel configurations.
- You need to run menuconfig inside the Yocto BitBake environment.
- Thus, the environment must be set up using the &OE_INIT_FILE;
- script found in the build directory.
- If you have not sourced this script do so with the following commands:
-
- $ cd ~/poky
- $ source &OE_INIT_FILE;
-
-
-
-
- After setting up the environment to run menuconfig, you are ready
- to use the tool to interactively change the kernel configuration.
- In this example, we are basing our changes on the linux-yocto-3.4
- kernel.
- The OpenEmbedded build system recognizes this kernel as
- linux-yocto.
- Thus, the following commands from the shell in which you previously sourced the
- environment initialization script cleans the shared state cache and the
- WORKDIR
- directory and then builds and launches menuconfig:
-
- $ bitbake linux-yocto -c menuconfig
-
-
-
-
- Once menuconfig launches, navigate through the user interface
- to find the CONFIG_SMP configuration setting.
- You can find it at Processor Type and Features.
- The configuration selection is
- Symmetric Multi-processing Support.
- After using the arrow keys to highlight this selection, press "n" to turn it off.
- Then, exit out and save your selections.
-
-
-
- Once you save the selection, the .config configuration file
- is updated.
- This is the file that the build system uses to configure the Yocto Project kernel
- when it is built.
- You can find and examine this file in the build directory.
- This example uses the following:
-
- ~/poky/build/tmp/work/qemux86-poky-linux/linux-yocto-3.4.11+git1+84f...
- ...656ed30-r1/linux-qemux86-standard-build
-
-
- The previous example directory is artificially split and many of the characters
- in the actual filename are omitted in order to make it more readable.
- Also, depending on the kernel you are using, the exact pathname might differ
- slightly.
-
-
-
-
- Within the .config file, you can see the following setting:
-
- # CONFIG_SMP is not set
-
-
-
-
- A good method to isolate changed configurations is to use a combination of the
- menuconfig tool and simple shell commands.
- Before changing configurations with menuconfig, copy the
- existing .config and rename it to something else,
- use menuconfig to make
- as many changes an you want and save them, then compare the renamed configuration
- file against the newly created file.
- You can use the resulting differences as your base to create configuration fragments
- to permanently save in your kernel layer.
-
- Be sure to make a copy of the .config and don't just
- rename it.
- The build system needs an existing .config
- from which to work.
-
-
-
-
-
- Recompiling the Kernel and Testing the New Configuration
-
-
- At this point, you are ready to recompile your kernel image with
- the new setting in effect using the BitBake command below:
-
- $ bitbake linux-yocto
-
-
-
-
- Now run the QEMU emulator and pass it the same multi-processor option as before:
-
- $ runqemu qemux86 qemuparams="-smp 4"
-
-
-
-
- Login to the machine using root with no password
- and test for the number of processors the kernel supports:
-
- # cat /proc/cpuinfo | grep processor
- processor : 0
- #
-
-
-
-
- From the output, you can see that the kernel no longer supports multi-processor systems.
- The output indicates support for a single processor. You can verify the
- CONFIG_SMP setting by using this command:
-
- zcat /proc/config.gz | grep CONFIG_SMP
-
- The console returns the following output:
-
- # CONFIG_SMP is not set
-
- You have successfully reconfigured the kernel.
-
-
-
-
-
- Adding Kernel Recipes
-
-
- A future release of this manual will present an example that adds kernel recipes, which provide
- new functionality to the kernel.
-
-
-
-
-
-