Poky supports several methods of software development. You can use the method that is best for you. This chapter describes each development method.

The meta-toolchain and meta-toolchain-sdk targets build tarballs that contain toolchains and libraries suitable for application development outside of Poky. For information on these targets see the Reference: Images appendix. These tarballs unpack into the /opt/poky directory and contain a setup script (e.g. /opt/poky/environment-setup-i586-poky-linux), from which you can source to initialize a suitable environment. Sourcing these files adds the compiler, QEMU scripts, QEMU binary, a special version of pkgconfig and other useful utilities to the PATH variable. Variables to assist pkgconfig and autotools are also defined so that, for example, configure can find pre-generated test results for tests that need target hardware on which to run. Using the toolchain with autotool-enabled packages is straightforward - just pass the appropriate host option to configure. Following is an example: $ ./configure --host=arm-poky-linux-gnueabi For other projects it is usually a case of ensuring the cross tools are used: CC=arm-poky-linux-gnueabi-gcc and LD=arm-poky-linux-gnueabi-ld

Yocto Project supports both Anjuta and Eclipse IDE plug-ins to make developing software easier for the application developer. The plug-ins provide capability extensions to the graphical IDE allowing for cross compilation, deployment and execution of the output in a QEMU emulation session. Support of these plug-ins also allows for cross debugging and profiling. Additionally, the Eclipse plug-in provides a suite of tools that allows the developer to perform remote profiling, tracing, collection of power data, collection of latency data and collection of performance data.

To use the Eclipse plug-in, a toolchain and SDK built by Poky is required along with the Eclipse Framework (Helios 3.6.1). To install the plug-in you need to be in the Eclipse IDE and select the following menu: Help -> Install New Software Specify the target URL as . If you want to download the source code for the plug-in you can find it in the Poky git repository, which has a web interface, and is located at under IDE Plugins.

If you don't have the Eclipse IDE (Helios 3.6.1) on your system you need to download and install it from . Choose the Eclipse Classic, which contains the Eclipse Platform, Java Development Tools (JDT), and the Plug-in Development Environment. Due to the Java Virtual Machine's garbage collection (GC) process the permanent generation space (PermGen) is not cleaned up. This space stores meta-data descriptions of classes. The default value is set too small and it could trigger an out-of-memory error like the following: Java.lang.OutOfMemoryError: PermGen space This error causes the applications to hang. To fix this issue you can use the -vmargs option when you start Eclipse to increase the size of the permanent generation space: Eclipse -vmargs -XX:PermSize=256M

Once you have the Eclipse IDE installed and configured you need to install the Yocto plug-in. You do this similar to installing the Eclipse plug-ins in the previous section. Do the following to install the Yocto plug-in into the Eclipse IDE: Select the "Help -> Install New Software" item. In the "Work with:" area click "Add..." and enter the URL for the Yocto plug-in, which is Finish out the installation of the update similar to any other Eclipse plug-in.

To configure the Yocto Eclipse plug-in you need to select the mode and the architecture with which you will be working. Start by selecting "Preferences" from the "Window" menu and then select "Yocto SDK". If you normally will use an installed Yocto SDK (under /opt/poky) select “SDK Root Mode”. Otherwise, if your crosstool chain and sysroot are within your poky tree, select “Poky Tree Mode”. If you are in SDK Root Mode you need to provide your poky tree path, for example, $<Poky_tree>/build/. Next, you need to select the architecture. Use the drop down list and select the architecture that you’ll be primarily working against. For target option, select your typical target QEMU vs External hardware. If you choose QEMU, you’ll need to specify your QEMU kernel file with full path and the rootfs mount point. Yocto QEMU boots off user mode NFS. See the Developing Externally in QEMU section for how to set it up. To make your settings the defaults for every new Yocto project created using the Eclipse IDE, simply save the settings.

As an example, this section shows you how to cross-compile a Yocto C project that is autotools-based, deploy the project into QEMU, and then run the debugger against it. You need to configure the project, trigger the autogen.sh, build the image, start QEMU, and then debug. The following steps show how to create a Yocto autotools-based project using a given template: Select "File -> New -> Project" to start the wizard. Expand "C/C++" and select "C Project". Click "Next" and select a template (e.g. "Hello World ANSI C Project"). Complete the steps to create the new Yocto autotools-based project using your chosen template. By default, the project uses the Yocto preferences settings as defined using the procedure in the previous section. If there are any specific setup requirements for the newly created project you need to reconfigure the Yocto plug-in through the menu selection by doing the following: Select the "Project -> Invoke Yocto Tools -> Reconfigure Yocto" menu item. Complete the dialogue to specify the specific toolchain and QEMU setup information. To build the project follow these steps: Select "Project -> Reconfigure Project" to trigger the autogen.sh command. Select "Project -> Build" to build the project. To start QEMU follow these steps: Select "Run -> External Tools" and see if there is a QEMU instance for the desired target. If one exists, click on the instance to start QEMU. If your target does not exist, click "External Tools Configuration" and you should find an instance of QEMU for your architecture under the entry under "Program". Wait for the boot to complete. To deploy your project and start debugging follow these steps: Highlight your project in the project explorer. Select "Run -> Debug Configurations" to bring up your remote debugging configuration in the right-hand window. Expand “C/C++ Remote Application”. Select "projectname_ gdb_target-poky-linux". You need to be sure there is an entry for the remote target. If no entry exists, click "New..." to bring up the wizard. Use the wizard to select TCF and enter the IP address of you remote target in the “Host name:” field. Back in the Remote Debug Configure window, specify in the “Remote Absolute File Path for C/C++ Application” field the absolute path for the program on the remote target. By default, the program deploys into the remote target. If you don't want this behavior then check “Skip download to target path”. Click "Debug” to start the remote debugging session.

Remote tools allow you to perform system profiling, kernel tracing, examine power consumption, and so forth. To see and access the remote tools use the "Window -> YoctoTools" menu. Once you pick a tool you need to configure it for the remote target. Every tool needs to have the connection configured. You must select an existing TCF-based RSE connection to the remote target. If one does not exist, click "New" to create one. Here are some specifics about the remote tools: OProfile: Selecting this tool causes the oprofile-server on the remote target to launch on the local host machine. The oprofile-viewer must be installed on the local host machine and the oprofile-server must be installed on the remote target, respectively, in order to use . lttng: Selecting this tool runs "usttrace" on the remote target, transfers the output data back to the local host machine and uses "lttv-gui" to graphically display the output. The "lttv-gui" must be installed on the local host machine to use this tool. For information on how to use "lttng" to trace an application, see . For "Application" you must supply the absolute path name of the application to be traced by user mode lttng. For example, typing /path/to/foo" triggers "usttrace /path/to/foo" on the remote target to trace the program /path/to/foo. "Argument" is passed to "usttrace" running on the remote target. powertop: Selecting this tool runs "powertop" on the remote target machine and displays the results in a new view called "powertop". "Time to gather data(sec):" is the time passed in seconds before data is gathered from the remote target for analysis. "show pids in wakeups list:" corresponds to the -p argument passed to "powertop". latencytop and perf: "latencytop" identifies system latency, while "perf" monitors the system's performance counter registers. Selecting either of these tools causes an RSE terminal view to appear from which you can run the tools. Both tools refresh the entire screen to display results while they run.

Support for the Anjuta plug-in ends after Yocto project 0.9 Release. However, the source code can be downloaded from the git repository listed later in this section. The community is free to continue supporting it post 0.9 Release. An Anjuta IDE plug-in exists to make developing software within the Poky framework easier for the application developer familiar with that environment. The plug-in presents a graphical IDE that allows you to cross-compile, cross-debug, profile, deploy, and execute an application. To use the plug-in, a toolchain and SDK built by Poky, Anjuta, its development headers and the Anjuta Plug-in are all required. The Poky Anjuta Plug-in is available to download as a tarball at the OpenedHand labs page or directly from the Poky Git repository located at git://git.yoctoproject.org/anjuta-poky. You can access the source code from a web interface to the repository at under IDE Plugins. See the README file contained in the project for more information on Anjuta dependencies and building the plug-in. If you want to disable remote gdb debugging, pass the "--disable-gdb-integration" switch when you configure the plug-in.

Follow these steps to set up the plug-in: Extract the tarball for the toolchain into / as root. The toolchain will be installed into /opt/poky. To use the plug-in, first open or create an existing project. If you are creating a new project, the "C GTK+" project type will allow itself to be cross-compiled. However, you should be aware that this type uses "glade" for the UI. To activate the plug-in, select "Edit -> Preferences" and then choose "General" from the left hand side. Choose the "Installed plug-ins" tab, scroll down to "Poky SDK" and check the box. The plug-in is now activated but not configured.

You can find the configuration options for the SDK by choosing the Poky SDK icon from the left hand side. You need to define the following options: SDK root: If you use an external toolchain you need to set SDK root, which is the root directory of the SDK's sysroot. For an i586 SDK directory is /opt/poky/. This directory will contain "bin", "include", "var" and so forth under your selected target architecture subdirectory /opt/poky/sysroot/i586-poky-linux/. The cross-compile tools you need are in /opt/poky/sysroot/i586-pokysdk-linux/. Poky root: If you have a local Poky build tree, you need to set the Poky root, which is the root directory of the poky build tree. If you build your i586 target architecture under the subdirectory of build_x86 within your Poky tree, the Poky root directory should be $<poky_tree>/build_x86/. Target Architecture: This is the cross compile triplet, for example, "i586-poky-linux". This target triplet is the prefix extracted from the set up script file's name. For example, if the script file name is /opt/poky/environment-setup-i586-poky-linux then the extracted target triplet is "i586-poky-linux". Kernel: Use the file chooser to select the kernel used with QEMU. Root filesystem: Use the file chooser to select the root filesystem directory. This directory is where you use "poky-extract-sdk" to extract the poky-image-sdk tarball.

The steps in this section show how to cross-compile a project, deploy it into QEMU, run a debugger against it and then perform a system-wide profile. Choose "Build -> Run Configure" or "Build -> Run Autogenerate" to run "configure" or "autogen", respectively for the project. Either command passes command-line arguments to instruct the cross-compile. Choose "Build -> Build Project" to build and compile the project. If you have previously built the project in the same tree without using the cross-compiler you might find that your project fails to link. If this is the case, simply select "Build -> Clean Project" to remove the old binaries. After you clean the project you can then try building it again. Choose "Tools -> Start QEMU" to start QEMU. After QEMU starts any error messages will appear in the message view. Once Poky has fully booted within QEMU you can deploy the project into it. Once the project is built and you have QEMU running choose "Tools -> Deploy" to install the package into a temporary directory and then copy it using "rsync" over SSH into the target. A progress bar and appropriate messages appear in the message view. To debug a program installed onto the target choose "Tools -> Debug remote". Choosing this menu item causes prompts to appear to define the local binary for debugging and also for the command line used to run on the target. When you provide the command line be sure to include the full path to the to binary installed in the target. When the command line runs a "gdbserver" over SSH is started on the target and an instance of "cross-gdb" starts in a local terminal. The instance of "cross-gdb" will be preloaded to connect to the server and use the SDK root to find symbols. It also connects to the target and loads in various libraries as well as the target program. You should define any breakpoints or watchpoints at this point in the process since you might not be able to interrupt the execution later. To stop the debugger on the target choose "Tools -> Stop debugger". It is also possible to execute a command in the target over SSH. Doing so causes the appropriate environment to be established for execution. To execute a command choose "Choose Tools -> Run remote". This selection opens a terminal with the SSH command inside. To perform a system-wide profile against the system running in QEMU choose "Tools -> Profile remote". This choice starts up "OProfileUI" with the appropriate parameters to connect to the server running inside QEMU and also supplies the path for debug information necessary to get a useful profile.

Running Poky QEMU images is covered in the Yocto Project Quick Start in the "A Quick Test Run" section. Poky's QEMU images contain a complete native toolchain. This means you can develop applications within QEMU similar to the way you would in a normal system. Using qemux86 on an x86 machine is fast since the guest and host architectures match. On the other hand, using qemuarm can be slower but gives faithful emulation of ARM-specific issues. To speed things up, these images support using "distcc" to call a cross-compiler outside the emulated system. If "runqemu" was used to start QEMU, and "distccd" is present on the host system, any Bitbake cross-compiling toolchain available from the build system is automatically used from within QEMU simply by calling "distcc". You can accomplish this by defining the cross-compiler variable (e.g. export CC="distcc"). Alternatively, if a suitable SDK/toolchain is present in /opt/poky it is also automatically be used. There are several options for connecting into the emulated system. QEMU provides a framebuffer interface that has standard consoles available. There is also a serial connection available that has a console to the system running on it and uses standard IP networking. The images have a dropbear ssh server running with the root password disabled to allow standard ssh and scp commands to work. The images also contain an NFS server that exports the guest's root filesystem, which allows it to be made available to the host.

Working directly in Poky is a fast and effective development technique. The idea is that you can directly edit files in WORKDIR or the source directory S and then force specific tasks to rerun in order to test the changes. An example session working on the matchbox-desktop package might look like this: $ bitbake matchbox-desktop $ sh $ cd tmp/work/armv5te-poky-linux-gnueabi/matchbox-desktop-2.0+svnr1708-r0/ $ cd matchbox-desktop-2 $ vi src/main.c $ exit $ bitbake matchbox-desktop -c compile -f $ bitbake matchbox-desktop This example builds the package, changes into the work directory for the package, changes a file, then recompiles the package. Instead of using "sh" as it is in the example, you can also use two different terminals. However, the risk of using two terminals is that a command like "unpack" could destroy the changes you've made to the work directory. Consequently, you need to work carefully. It is useful when making changes directly to the work directory files to do so using "quilt" as detailed in the modifying packages with quilt section. You can copy the resulting patches into the recipe directory and use them directly in the SRC_URI. For a review of the skills used in this section see the Bitbake and Running Specific Tasks Sections.

When debugging certain commands or even when just editing packages, the 'devshell' can be a useful tool. Use a command like the following to start this tool. $ bitbake matchbox-desktop -c devshell This command opens a terminal with a shell prompt within the Poky environment. Consequently, the following occurs: The PATH variable includes the cross toolchain. The pkgconfig variables find the correct .pc files. "configure" finds the Poky site files as well as any other necessary files. Within this environment, you can run "configure" or "compile" commands as if they were being run by Poky itself. The working directory also automatically changes to the (S) directory. When you are finished, you just exit the shell or close the terminal window. The default shell used by "devshell" is the gnome-terminal. You can use other forms of terminal can by setting the TERMCMD and TERMCMDRUN variables in local.conf. For examples of the other options available, see meta/conf/bitbake.conf. An external shell is launched rather than opening directly into the original terminal window. This allows easier interaction with Bitbake's multiple threads as well as for a future client/server split. Note that "devshell" will still work over X11 forwarding or similar situations. It is worth remembering that inside "devshell" you need to use the full compiler name such as arm-poky-linux-gnueabi-gcc instead of just gcc. The same applies to other applications such as gcc, bintuils, libtool and so forth. Poky will have setup environmental variables such as CC to assist applications, such as make, find the correct tools.

If you're working on a recipe that pulls from an external SCM it is possible to have Poky notice new changes added to the SCM and then build the latest version using them. This only works for SCMs from which it is possible to get a sensible revision number for changes. Currently it works for svn, git and bzr repositories. To enable this behavior simply add SRCREV_pn- PN = "${AUTOREV}" to local.conf, where PN is the name of the package for which you want to enable automatic source revision updating.

GNU Project Debugger (GDB) allows you to examine running programs to understand and fix problems and also to perform post-mortem style analysis of program crashes. GDB is available as a package within Poky and by default is installed in sdk images. See for the GDB source. For best results install -dbg packages for the applications you are going to debug. Doing so makes available extra debug symbols that will give you more meaningful output. Sometimes, due to memory or disk space constraints, it is not possible to use GDB directly on the remote target to debug applications. These constraints arise because GDB needs to load the debugging information and the binaries of the process being debugged. Additionally, GDB needs to perform many computations to locate information such as function names, variable names and values, stack traces and so forth - even before starting the debugging process. These extra computations place more load on the target system and can alter the characteristics of the program being debugged. To help get past these constraints you can use GDBSERVER. It runs on the remote target and does not load any debugging information from the debugged process. Instead, a GDB instance processes the debugging information that is run on a remote computer - the host GDB. The host GDB then sends control commands to GDBSERVER to make it stop or start the debugged program, as well as read or write memory regions of that debugged program. All the debugging information loaded and processed as well as all the heavy debugging is done by the host GDB. Offloading these processes gives the GDBSERVER running on the target a chance to remain small and fast. Because the host GDB is responsible for loading the debugging information and for doing the necessary processing to make actual debugging happen, the user has to make sure the host can access the unstripped binaries complete with their debugging information and also compiled with no optimizations. The host GDB must also have local access to all the libraries used by the debugged program. Because GDBSERVER does not need any local debugging information the binaries on the remote target can remain stripped. However, the binaries must also be compiled without optimization so they match the host's binaries. To remain consistent with GDB documentation and terminology the binary being debugged on the remote target machine is referred to as the 'inferior' binary. For documentation on GDB see the GDB site at on their site.

First, make sure GDBSERVER is installed on the target. If not, install the package gdbserver, which needs the libthread-db1 package. As an example, to launch GDBSERVER on the target and make it ready to "debug" a program located at /path/to/inferior, connect to the target and launch: $ gdbserver localhost:2345 /path/to/inferior GDBSERVER should now be listening on port 2345 for debugging commands coming from a remote GDB process that is running on the host computer. Communication between GDBSERVER and the host GDB are done using TCP. To use other communication protocols please refer to the GDBSERVER documentation.

Running GDB on the host computer takes a number of stages. This section describes those stages.

A suitable GDB cross-binary is required that runs on your host computer but also knows about the the ABI of the remote target. You can get this binary from the the Poky toolchain - for example: /usr/local/poky/eabi-glibc/arm/bin/arm-poky-linux-gnueabi-gdb where "arm" is the target architecture and "linux-gnueabi" the target ABI. Alternatively, Poky can build the gdb-cross binary. For example, the following command builds it: $ bitbake gdb-cross Once the binary is built you can find it here: tmp/sysroots/<host-arch</usr/bin/<target-abi>-gdb

The inferior binary (complete with all debugging symbols) as well as any libraries (and their debugging symbols) on which the inferior binary depends need to be available. There are a number of ways you can make these available. Perhaps the easiest is to have an 'sdk' image that corresponds to the plain image installed on the device. In the case of 'poky-image-sato', 'poky-image-sdk' would contain suitable symbols. Because the sdk images already have the debugging symbols installed it is just a question of expanding the archive to some location and then informing GDB. Alternatively, Poky can build a custom directory of files for a specific debugging purpose by reusing its tmp/rootfs directory. This directory contains the contents of the last built image. This process assumes two things: The image running on the target was the last image to be built by Poky. The package (foo in the following example) that contains the inferior binary to be debugged has been built without optimization and has debugging information available. These steps show how to build the custom directory of files: Install the package (foo in this case) to tmp/rootfs: tmp/sysroots/i686-linux/usr/bin/opkg-cl -f \ tmp/work/<target-abi>/poky-image-sato-1.0-r0/temp/opkg.conf -o \ tmp/rootfs/ update Install the debugging information: tmp/sysroots/i686-linux/usr/bin/opkg-cl -f \ tmp/work/<target-abi>/poky-image-sato-1.0-r0/temp/opkg.conf \ -o tmp/rootfs install foo tmp/sysroots/i686-linux/usr/bin/opkg-cl -f \ tmp/work/<target-abi>/poky-image-sato-1.0-r0/temp/opkg.conf \ -o tmp/rootfs install foo-dbg

To launch the host GDB, you run the cross-gdb binary and provide the inferior binary as part of the command line. For example, the following command form continues with the example used in the previous section. This command form loads the foo binary as well as the debugging information: $ <target-abi>-gdb rootfs/usr/bin/foo Once the GDB prompt appears, you must instruct GDB to load all the libraries of the inferior binary from tmp/rootfs as follows: $ set solib-absolute-prefix /path/to/tmp/rootfs The pathname /path/to/tmp/rootfs must either be the absolute path to tmp/rootfs or the location at which binaries with debugging information reside. At this point you can have GDB connect to the GDBSERVER that is running on the remote target by using the following command form: $ target remote remote-target-ip-address:2345 The remote-target-ip-address is the IP address of the remote target where the GDBSERVER is running. Port 2345 is the port on which the GDBSERVER is running.

You can now proceed with debugging as normal - as if you were debugging on the local machine. For example, to instruct GDB to break in the "main" function and then continue with execution of the inferior binary use the following commands from within GDB: (gdb) break main (gdb) continue For more information about using GDB, see the project's online documentation at .

OProfile is a statistical profiler well suited for finding performance bottlenecks in both userspace software and in the kernel. This profiler provides answers to questions like "Which functions does my application spend the most time in when doing X?" Because Poky is well integrated with OProfile it makes profiling applications on target hardware straightforward. To use OProfile you need an image that has OProfile installed. The easiest way to do this is with "tools-profile" in IMAGE_FEATURES. You also need debugging symbols to be available on the system where the analysis takes place. You can gain access to the symbols by using "dbg-pkgs" in IMAGE_FEATURES or by installing the appropriate -dbg packages. For successful call graph analysis the binaries must preserve the frame pointer register and should also be compiled with the "-fno-omit-framepointer" flag. In Poky you can achieve this by setting SELECTED_OPTIMIZATION to "-fexpensive-optimizations -fno-omit-framepointer -frename-registers -O2". You can also achieve it by setting DEBUG_BUILD to "1" in local.conf. If you use the DEBUG_BUILD variable you will also add extra debug information that can make the debug packages large.

Using OProfile you can perform all the profiling work on the target device. A simple OProfile session might look like the following: # opcontrol --reset # opcontrol --start --separate=lib --no-vmlinux -c 5 [do whatever is being profiled] # opcontrol --stop $ opreport -cl In this example, the reset command clears any previously profiled data. The next command starts OProfile. The options used when starting the profiler separate dynamic library data within applications, disable kernel profiling, and enable callgraphing up to five levels deep. To profile the kernel, you would specify the --vmlinux=/path/to/vmlinux option. The vmlinux file is usually in /boot/ in Poky and must match the running kernel. After you perform your profiling tasks, the next command stops the profiler. After that you can view results with the "opreport" command with options to see the separate library symbols and callgraph information. Callgraphing logs information about time spent in functions and about a function's calling function (parent) and called functions (children). The higher the callgraphing depth, the more accurate the results. However, higher depths also increase the logging overhead. Consequently, you should take care when setting the callgraphing depth. On ARM, binaries need to have the frame pointer enabled for callgraphing to work. To accomplish this use the -fno-omit-framepointer option with gcc. For more information on using OProfile, see the OProfile online documentation at .

A graphical user interface for OProfile is also available. You can download and build it from svn at . If the "tools-profile" image feature is selected, all necessary binaries are installed onto the target device for OProfileUI interaction. In order to convert the data in the sample format from the target to the host you need the opimport program. This program is not included in standard Debian OProfile packages. However, an OProfile package with this addition is available from the OpenedHand repository. We recommend using OProfile 0.9.3 or greater. Even though Poky usually includes all needed patches on the target device, you might find you need other OProfile patches for recent OProfileUI features. If so, see the OProfileUI README for the most recent information. You can also see OProfileUI website for general information on the OProfileUI project.

Using OProfile in online mode assumes a working network connection with the target hardware. With this connection, you just need to run "oprofile-server" on the device. By default OProfile listens on port 4224. You can change the port using the --port command-line option. The client program is called "oprofile-viewer" and its UI is relatively straightforward. You access key functionality through the buttons on the toolbar, which are duplicated in the menus. The buttons are: Connect - Connects to the remote host. You can also supply the IP address or hostname. Disconnect - Disconnects from the target. Start - Starts profiling on the device. Stop - Stops profiling on the device and downloads the data to the local host. Stopping the profiler generates the profile and displays it in the viewer. Download - Downloads the data from the target and generates the profile, which appears in the viewer. Reset - Resets the sample data on the device. Resetting the data removes sample information collected from previous sampling runs. Be sure you reset the data if you do not want to include old sample information. Save - Saves the data downloaded from the target to another directory for later examination. Open - Loads previously saved data. The client downloads the complete 'profile archive' from the target to the host for processing. This archive is a directory that contains the sample data, the object files and the debug information for the object files. The archive is then converted using the "oparchconv" script, which is included in this distribution. The script uses "opimport" to convert the archive from the target to something that can be processed on the host. Downloaded archives reside in /tmp and are cleared up when they are no longer in use. If you wish to perform kernel profiling you need to be sure a "vmlinux" file that matches the running kernel is available. In Poky, that file is usually located in /boot/vmlinux-KERNELVERSION, where KERNEL-version is the version of the kernel (e.g. 2.6.23). Poky generates separate vmlinux packages for each kernel it builds so it should be a question of just making sure a matching package is installed - for example: opkg install kernel-vmlinux. The files are automatically installed into development and profiling images alongside OProfile. There is a configuration option within the OProfileUI settings page where you can enter the location of the vmlinux file. Waiting for debug symbols to transfer from the device can be slow, and it is not always necessary to actually have them on the device for OProfile use. All that is needed is a copy of the filesystem with the debug symbols present on the viewer system. The "Launching GDB on the Host Computer" section covers how to create such a directory with Poky and how to use the OProfileUI Settings dialog to specify the location. If you specify the directory, it will be used when the file checksums match those on the system you are profiling.

If network access to the target is unavailable, you can generate an archive for processing in "oprofile-viewer" as follows: # opcontrol --reset # opcontrol --start --separate=lib --no-vmlinux -c 5 [do whatever is being profiled] # opcontrol --stop # oparchive -o my_archive In the above example my_archive is the name of the archive directory where you would like the profile archive to be kept. After the directory is created, you can copy it to another host and load it using "oprofile-viewer" open functionality. If necessary, the archive is converted.