path: root/docs/part-1/5_debug-first-app.md

# Debug your first AGL application

Debug is based on gdb and you need to use `xds-gdb` as a wrapper on gdb to cross-debug your application.
This tool allows you to debug an application built with an xds-server without the need to install gdb or any cross tool.
Two debugging models are supported:

1. native debugging

1. XDS remote debugging requiring an XDS server and allowing cross debug your
  application.

 By default XDS remote debug is used and you need to define `XDS_NATIVE_GDB`
variable to use native gdb debug mode instead.

> **SEE ALSO**: [xds-server](https://github.com/iotbzh/xds-server), a web server
used to remotely cross build applications.
> **SEE ALSO**: [xds-exec](https://github.com/iotbzh/xds-exec),
wrappers on `exec` command that allows to cross build your application through `xds-server`.

## Configuration

 `xds-gdb` configuration is defined by variables (see listed below).
 These variables may be set using :

- environment variables (inherited),
- or a config file set with `XDS_CONFIG` environment variable, for example:
  `XDS_CONFIG=/tmp/my_xds_gdb_config.env xds-gdb`
- or by setting variables within a gdb ini file (see details below),
- or a "user" config file located in following directory (first found is taken):
  1. $(CURRENT_DIRECTORY)/.xds-gdb.env
  1. $(CURRENT_DIRECTORY)/../xds-gdb.env
  1. $(CURRENT_DIRECTORY)/target/xds-gdb.env
  1. $(HOME)/.config/xds/xds-gdb.env

### Configuration Variables

 `XDS_CONFIG`
 Config file defining `XDS_xxx` configuration variables. Variables of this file
 will overwrite inherited environment variables. Variables definition may be
 prefixed or not by "export" keyword.
 Here is an example of configuration file

```bash
# for example:
# MY_PROJECT_DIR=/home/seb/xds-workspace/helloworld-native-application
cat > $MY_PROJECT_DIR/xds-gen3.conf << EOF
export XDS_SERVER_URL=http://docker:8000
export XDS_PROJECT_ID=IW7B4EE-DBY4Z74_myProject
export XDS_SDK_ID=poky-agl_aarch64_4.0.1
EOF
```

`XDS_LOGLEVEL`

Set logging level (supported levels: panic, fatal, error, warn, info, debug)

`XDS_LOGFILE`

Set logging file, default `/tmp/xds-gdb.log`.

`XDS_NATIVE_GDB`

Use native gdb mode instead of remote XDS server mode.

`XDS_PROJECT_ID`  *(mandatory with XDS server mode)*

Project ID you want to build

`XDS_RPATH`

Relative path into project

`XDS_SDK_ID`   *(mandatory with XDS server mode)*

Cross Sdk ID to use to build project

`XDS_SERVER_URL`    *(mandatory with XDS server mode)*

Remote XDS server url

### Configuration variables set within gdb init command file

Above `XDS_xxx` variables may also be defined within gdb init command file
(see --command or -x option of genuine Gdb).
You must respect the following syntax: commented line including `:XDS-ENV:` tag

Example of gdb init file where we define project and sdk ID:

```bash
     # :XDS-ENV: XDS_PROJECT_ID=IW7B4EE-DBY4Z74_myProject
     # :XDS-ENV: XDS_SDK_ID=poky-agl_aarch64_4.0.1
```

## Using xds-gdb from command line

### XDS remote debugging mode

First the project you want to debug must be declared on an xds-server and this
project may also has been built using this xds-server (see [xds-server](https://github.com/iotbzh/xds-server) for more details).

So to debug it you need to know the xds-server url (eg. <http://docker:8000>),
you also need the project and sdk unique id. You can find these IDs in project
page of XDS dashboard or you can get them from command line using the `--list`
option.
This option lists all existing projects ID:

```bash
XDS_SERVER_URL=http://docker:8000 xds-gdb --list
```

Now to refer your project, just set `XDS_PROJECT_ID` and `XDS_SDK_ID` variables.

You are now ready to use `xds-gdb` to for example cross debug your project.
Here is an example to build and debug a project based on CMakefile and
[AGL app-templates](https://git.automotivelinux.org/apps/app-templates/):

```bash
# Go into your project directory (for example helloworld-native-application)
cd ~/xds-workspace
git clone https://github.com/iotbzh/helloworld-native-application.git
cd helloworld-service

# Declare your project on xds-server
# <for now, you can only do this step using xds HTML dashboard (see xds-server doc)>

# Define XDS config
cat <<EOF >./xds-config.env
XDS_SERVER_URL=http://docker:8000
XDS_PROJECT_ID=IW7B4EE-DBY4Z74_myProject
XDS_SDK_ID=poky-agl_aarch64_4.0.1
EOF

# Tell to xds-exec and xds-gdb which is your config file
export XDS_CONFIG=../xds-gen3.conf

# Create a new build directory
mkdir build && cd build

# Start remote cross build
xds-exec -- cmake -DRSYNC_TARGET=root@myTarget ..
xds-exec -- make
xds-exec -- make remote-target-populate

# Start debugging
xds-gdb -x target/gdb-on-root@myTarget.ini
```

<!-- note -->
> **Note** : [helloworld-native-application](https://github.com/iotbzh/helloworld-native-application) project is an AGL
project based on [app-templates](https://git.automotivelinux.org/apps/app-templates/)
(included as a git submodule). This CMake templating, used to develop application
with the AGL Application Framework, will automatically generate makefile rules
(eg. `remote-target-populate`) or scripts (eg. `build/target/xxx` scripts).

For more info about app-template, please refer to [this documentation](http://docs.automotivelinux.org/docs/devguides/en/dev/reference/sdk-devkit/docs/part-2/2_4-Use-app-templates.html).
<!-- endnote -->

### Native debugging

To enable native debugging mode, you need to define `XDS_NATIVE_GDB` variable.

## Using xds-gdb within an IDE

### Netbeans

__Netbeans 8.x :__

- Open menu **Tools** -> **Options**
  - Open **C/C++** tab, in **Build Tools** sub-tab, click on **Add** button:

    ![Add new tool panel](./pictures/nb_newtool.png){:: style="width:90%;"}

  - Then, you should set **Make Command** and **Debugger Command** to point to xds tools:

    ![Add new tool panel](./pictures/nb_xds_options.png){:: style="width:90%;"}

  - Finally click on **OK** button.

- Edit project properties (using menu **File** -> **Project Properties**) to update Debug settings:

  - Be sure that "Gen3 board" configuration is selected

  - Select **Run** category, and set:
    - Run Command: `target/start-on-root@renesas-gen3.sh`
      (_script name may depend of RSYNC_TARGET variable you set in pre-build command_)
    - Run Directory: `build_gen3`

  - Select **Debug** category, and set:
    - Debug command: `/bin/true`
    - Working Directory: _empty field_
    - Gdb Init File: `target/gdb-on-root@renesas-gen3.ini`
      (_script name may depend of RSYNC_TARGET variable you set in pre-build command_)

    ![Select Model panel](./pictures/nb_project_debug-1.png){:: style="width:90%;"}

  - Click on **Apply** and then **OK** button to save settings

You can now start debugging your application with menu **Debug** -> **Debug Project** (or **CTRL+F5** shortcut)

### Others IDE

*Coming soon...*