TipsAndTricks/RunningEclipseAgainstBuiltImage

Cookbook guide to Making an Eclipse Debug Capable Image

Suppose you are building images and would like to be able to use Eclipse and the Yocto Eclipse plugin to develop/debug a C/C++ application on either a remote hardware target or on qemu. This cookbook will explain the small number of steps needed to accomplish this.
So that the commands are specific and can be cut and pasted to try, we will assume the following:

• Target Image-> core-image-sato-sdk
  • see bottom sec #Why SDK Image
• Target Machine -> qemux86

Making a Suitable Qemux86 Image

• We need to build a core-image-sato-sdk that has the pieces needed by Eclipse, so we add/change the following in our conf/local.conf:
  • We add the following to EXTRA_IMAGE_FEATURES in conf/local.conf
    • EXTRA_IMAGE_FEATURES += " eclipse-debug "
      • This adds gdbserver,tcf-agent (for Target Communication Framework), and openssh-sftp-server)
    • EXTRA_IMAGE_FEATURES += " tools-sdk "
      • This adds the build requirements on the target rootfs. This is needed since the Yocto Eclipse plugin is assuming that the qemu rootfs and the sysroot are synonymous.
    • EXTRA_IMAGE_FEATURES += " ssh-server-openssh "
      • This defaults to the openssl ssh server rather than dropbear. You can use either so this line can be omitted since the sftp server works with either.
  • Execute: $bitbake core-image-sato
    • This makes a rootfs in tmp/deploy/images/qemux86/core-image-sato-qemux86.tar.bz2
• We need to build the toolchain eclipse will use
  • Execute $bitbake core-image-sato -c populate_sdk
    • This makes sdk stuff such as the toolchains eclipse will use to build,
• We need to build a version of qemu that can run natively on our workstation as well as a userspace nfs daemon.
  • Execute $bitbake meta-ide-support
• We need an extracted rootfs that can be used by the userspace nfs daemon to boot qemu.
  • Execute $mkdir MY_QEMU_ROOTFS
    • Execute $runqemu-extract-sdk tmp/deploy/images/qemux86/core-image-sato-qemux86.tar.bz2 MY_QEMU_ROOTFS
      • This will result in a fully extracted rootfs in MY_QEMU_ROOTFS and a set of permissions maintained by pseudo (a yocto tool similar to but more functional than fakeroot) for the rootfs in MY_QEMU_ROOTFS.pseudo_state

Running Eclipse Against the Built Qemux86 Image

This Cookbook assumes you have already installed the Eclipse Poky plugin following the directions in http://www.yoctoproject.org/docs/latest/sdk-manual/sdk-manual.html. Assuming that is true, you can

Set up the Configuration For the Built Image

• Goto Windows->Preferences->Yocto Project SDK
  • Select Build System Derived Toolchain
  • enter Toolchain Root Location: <build dir>
    • this is where you have been running bitbake core-image-sato, bitbake etc.
  • enter Sysroot Location: <path>/MY_QEMU_ROOTFS
    • this is where you extracted the core-image-sato-qemux86.tar.bz2 to by running runqemu-extract-sdk
  • enter Qemu/Kernel: <path>/tmp/deploy/images/qemux86/bzImage-qemux86.bin
    • this is the kernel we built
  • You should now see i586-poky-linux in the Target Architecture dropdown list.
  • hit apply and ok

Alternatively, Downloading what we need for Qemux86

Sometimes, you may not want to build everything yourself but just want to download what you need. These instructions will target the Yocto 2.1 release, but you should be able to translate it into other releases pretty easily.

• Download the image http://downloads.yoctoproject.org/releases/yocto/yocto-2.1/machines/qemu/qemux86/core-image-sato-sdk-qemux86.tar.bz2 Note, the image MUST be an SDK image. Images without sdk in the name will NOT work.
• Download the toolchain: http://downloads.yoctoproject.org/releases/yocto/yocto-2.1/toolchain/x86_64/poky-glibc-x86_64-core-image-sato-i586-toolchain-2.1.sh Note, the toolchain must NOT be one with -ext in the name. The ext toolchains are for the extensible SDK which is useful for CLI and recipe development but which is not currently compatible with Eclipse.
• unpack the toolchain to a dir by running the shell script file you downloaded:

$chmod a+x poky-glibc-x86_64-core-image-sato-i586-toolchain-2.1.sh 
$sh poky-glibc-x86_64-core-image-sato-i586-toolchain-2.1.sh 

This will put the toolchain in /opt/poky/2.1 by default.

• source the toolchain environment file

 $source environment-setup-i586-poky-linux 

• extract the image you downloaded so that Qemu can use it

 $runqemu-extract-sdk core-image-sato-sdk-qemux86.tar.bz2  MY_QEMU_ROOTFS 

• Downloads a kernel Qemu can use to boot: http://downloads.yoctoproject.org/releases/yocto/yocto-2.1/machines/qemu/qemux86/bzImage-qemux86.bin

Running Eclipse Against the Downloaded Image

This Cookbook assumes you have already installed the Eclipse Poky plugin following the directions in http://www.yoctoproject.org/docs/latest/sdk-manual/sdk-manual.html. Assuming that is true, you can

Set up the Configuration For the Downloaded Image

• Goto Windows->Preferences->Yocto Project SDK
  • Select Standalone pre built toolchain
  • enter Toolchain Root Location: /opt/poky/2.1
  • enter Sysroot Location: <path>/MY_QEMU_ROOTFS
    • this is where you extracted the core-image-sato-qemux86.tar.bz2 to by running runqemu-extract-sdk
  • enter Qemu/Kernel: bzImage-qemux86.bin
    • this is the kernel you downloaded
  • You should now see i586-poky-linux in the Target Architecture dropdown list.
  • hit apply and ok

Run Qemu

• goto Run->External Tools-> External Tools Configurations... and select qemu_i586-poky-linux (in our example; in general it will be architecture-distro-os)
  • click Run - this will bring up a Qemu instance.

Put the binary on the Qemu instance and debug it

• goto Run->Debug Configurations... and select your project (looks like hello_gdb_i586-poky-linux in our case if you named the project hello)
• make a new connection - I prefer SSH so I'll show that here. TCF should also work.
  • Click New... on Connection line
  • put 192.168.7.2 (probably, look at the end of the qemu xterm that launched and find ip=192.168.7.XX::192.168.7.XX-1 ) in the Host name
  • name it
  • click finish
• Browse to where the prog will go. I tend to use /home/root.
  • Remote Absolute File Path for C/C++ Application -> click Browse...
  • Goto Root->/->home->root remember the user is root and the password is empty by default.
  • double click root
  • click ok
• click Apply
• click Debug and open the Debug Perspective.

Other Useful Info

Adding static tap devices

It is often easier to preconfigure several tap devices so that qemu can run and use them without needing to be root or use sudo. To do this, run runqemu-gen-tapdevs `id -u <username>` `id -g <username>` 4 `find ./tmp/sysroots -iname tunctl` as root. This will make the inet devices tap0,tap1,tap2,tap3. You can see them with ifconfig -a | grep tap . Typically, tap0 is 192.168.7.1 and so when the first qemu is run it's address will be 192.168.7.2 and 192.168.7.1 will be that qemu instance's gateway. The runqemu-gen-tapdevs is located in bitbake/scripts.

scripts/runqemu-gen-tapdevs

Switching autotools C/C++ project from one toolchain/sysroot to another and build failing

Sometimes you will have an existing project and want to switch to a different toolchain or sysroot or machine (x86->x86-64 for instance). If you find that you are getting errors like install-sh not found it may mean that your autotools files have gotten out of sync. Here's how you can force them back. All of these are found by Right clicking on the project and going to Invoke Autotools->:

 Invoke Libtoolize  option = "--force"
 Invoke Aclocal
 Invoke Autoheader
 Invoke Automake  option = "--force-missing --add-missing"
 Invoke Autoconf

Then Right click on the project and select Reconfigure Project . You should now be able to build the project again.