How to use development image

Introduction

The dev image is a super-set of its corresponding production image for each variant, furthermore, it includes some more packages and tools, e.g. gdb, strace, etc. for the sake of developing an debugging convenience. Therefore, the dev image will be delivered together with the production image for each variant in the end.

Get dev image:

There are two ways to get the dev image:

  1. Download pre-build image from CI server

  2. Build locally

Boot up QEMU dev image

The handy QEMU launch script qemu_launcher is used to boot up dev image

./qemu_launcher -f FOLDER -i core-image-pelux-minimal-qemux86-64.ext4 --dev

Note that the SSH port 22 is forwarded to 1234 by default, and an extra port 3333 is also exposed by the command for remote debugging later. To learn more about boot up QEMU see Booting up a QEMU image or check the usage of the script

./qemu_launcher -h

The QEMU dev image can be accessed via SSH now

$ ssh root@127.0.0.1 -p 1234

The instructions above covered how to obtain the SDK and boot up QEMU dev image, steps below will show cross-compiling an example service (template-service) for the target, and then run a remote debugger on it.

Cross compile template-service

SDK can be fetched from pre-build CI server or local build, the same as way fetching images.

  • Install SDK

cd <SDK location>
chmod +x pelux-glibc-x86_64-<image-name>-<arch>-toolchain-<version>.sh
./pelux-glibc-x86_64-<image-name>-<arch>-toolchain-<version>.sh

More details see Installing the SDK

  • Cross Compiling

cd <SDK location>
source environment-setup-<arch>-poky-linux

Note that template-service should be cloned into your local disk

cd <template-service folder>
mkdir build && cd build
cmake ..
make

More details see Sourcing The Environment

  • Deploy to target

scp build/template-service root@<ip address>:

Now the binary file has been copied to the target and it can be run there.

ssh root@<ip address>
./template-service

Remote Debugging

The script gdb_helper has wrapped the functions needed to deal with gdb and gdbserver

./gdb_helper -h
usage: ./gdb_helper [options]
[options] is any of the following:
  -f | --file                   Transfer the executable file to the target and start gdb
  -d | --dest                   The destination folder on target where the file will be transferred
  -P | --PID                    The PID on target to be attached
  -i | --target_ip              The target IP address. Defaults to 127.0.0.1
  -p | --ssh_port               SSH port to connect to QEMU. Defaults to 1234
  -t | --gdb_port               The port for remote debugging. Defaults to 3333
  -s | --server                 Start gdbserver on target
  -g | --gdb                    Start gdb on development machine
  -h | --help                   Display this help

  • Start gdbserver

./gdb_helper --server

It will start gdbserver on target to listen connection from port 3333, which is exposed previously

./gdb_helper --gdb

  • Start gdb and connect to target

If the executable program is not deployed to target yet, the script can be used to transfer the file to destination folder on target

./gdb_helper --file exe_file --dest DEST