<<<
:sectnums:
== Eclipse IDE

Eclipse (https://www.eclipse.org/) is a free and open-source interactive development environment that can be used
to develop, debug and profile application code for the NEORV32 RISC-V Processor. This chapter shows how to import
the provided **example setup** from the NEORV32 project repository. Additionally, all the required steps to create
a compatible project from scratch are illustrated in this chapter.

.This is a Makefile-Based Eclipse Project!
[IMPORTANT]
Note that the provided Eclipse example project (as well as the setup tutorial in this section) implements a
**makefile-based project**. Hence, the makefile in the example folder is used for building the application
instead of the Eclipse-managed build system. Therefore, **all compiler options, include folder, source files,
etc. have to be defined within this makefile**.

.Developing and debugging code for the NEORV32 using the Eclipse IDE
image::eclipse.png[align=center]


:sectnums:
=== Eclipse Prerequisites

The following tools are required:

* Eclipse IDE (**Eclipse IDE for Embedded C/C++ Developers**): https://www.eclipse.org/downloads/
* Precompiled RISC-V GCC toolchain: e.g. https://github.com/xpack-dev-tools/riscv-none-elf-gcc-xpack
* Precompiled OpenOCD binaries: e.g. https://github.com/xpack-dev-tools/openocd-xpack
* Build tools like `make` and busybox: e.g. https://github.com/xpack-dev-tools/windows-build-tools-xpack

.XPack Windows Build Tools
[TIP]
Some NEORV32 makefile targets relies on the `basename` command which might not be part of the default
XPack Windows Build Tools. However, you can just open the according `bin` folder, copy `busybox.exe`
and rename that copy to `basename.exe`.


:sectnums:
=== Import The Provided Eclipse Example Project

A preconfigured Eclipse project is available in `neorv32/sw/example/eclipse`.
To import it:

[start=1]
. Open Eclipse.
. Click on **File > Import**, expand **General** and select **Projects from Folder or Archive**.
. Click **Next**.
. Click on **Directory** and select the provided example project folder (see directory above).
. Click **Finish**.

.NEORV32 Folder and File Paths
[IMPORTANT]
The provided example project uses **relative paths** for including all the NEORV32-specific files and folders
(in the Eclipse configuration files). Note that these paths need to be adjusted when moving the example setup
to a different location.

.Tool Configuration
[IMPORTANT]
Make sure to adjust the binaries / installation folders of the RISC-V GCC toolchain, openOCD and Windows build tools
according to your installation. See the section <<_configure_build_tools>> for more information.

.Makefile Adjustment
[IMPORTANT]
Make sure to adjust the variables inside the project's makefile to match your processor
configuration (memory sizes, CPU ISA configuration, etc.):
https://stnolting.github.io/neorv32/#_application_makefile


:sectnums:
=== Setup a new Eclipse Project from Scratch

This chapter shows all the steps required to create an Eclipse project for the NEORV32 entirely from scratch.

==== Create a new Project

[start=1]
. Select **File > New > Project**.
. Expand **C/C++** and select **C++ project**.
. In the **C++ Project** wizard:
* Enter a **Project name**.
* Uncheck the box next to **Use default location** and specify a location using **Browse** where you want to create the project.
* From the **Project type** list expand **Makefile project** and select **Empty Project**.
* Select **RISC-V Cross GCC** from the **Toolchain** list on the right side.
* Click **Next**.
* Skip the next page using the default configuration by clicking **Next**.
. In the **GNU RISC-V Cross Toolchain** wizard configure the **Toolchain name** and **Toolchain path** according to your RISC-V GCC installation.
* Example: `Toolchain name: xPack GNU RISC-V Embedded GCC (riscv-none-elf-gcc)`
* Example: `Toolchain path: C:\Program Files (x86)\xpack-riscv-none-elf-gcc-13.2.0-2\bin`
. Click **Finish**.

If you need to reconfigure the RISC-V GCC binaries and/or paths:

[start=1]
. right-click on the project in the left view, select **Properties**
. expand **MCU** and select **RISC-V Toolchain Paths**
. adjust the **Toolchain folder** and the **Toolchain name** if required
. Click **Apply**.

==== Add Initial Files

Start a simple project by adding two initial files. Further files can be added later. Only the makefile is really
relevant here.

[start=1]
. Add a new file by right-clicking on the project and select **New > File** and enter `main.c` in the filename box.
. Add another new file by right-clicking on the project and select **New > File** and enter `makefile` in the filename
. Copy the makefile of an existing NEORV32 example program and paste it to the new (empty) makefile.

==== Add Build Targets (optional)

This step adds some of the targets of the NEORV32 makefile for easy access. This step is optional.

[start=1]
. In the project explorer right-click on the project and select **Build Target > Create...**.
. Add "`all`" as **Target name** (keep all the default checked boxes).
. Repeat these steps for all further targets that you wish to add (e..g `clean_all`, `exe`, `elf`).

.Clean-All Target
[TIP]
Adding the `clean_all` target is highly recommended. Executing this target once after importing the project ensures
that there are no (incompatible) artifacts left from previous builds.

.Available Target
[TIP]
See the NEORV32 data sheet for a list and description of all available makefile targets:
https://stnolting.github.io/neorv32/#_makefile_targets

==== Configure Build Tools

This step is only required if your system does not provide any build tools (like `make`) by default.

[start=1]
. In the project explorer right-click on the project and select **Properties**.
. Expand **MCU** and click on **Build Tools Path**.
. Configure the **Build tools folder**.
* Example: `Build tools folder: C:/xpack/xpack-windows-build-tools-4.4.1-2/bin`
. Click **Apply and Close**.

==== Adjust Default Build Configuration (optional)

This will simplify the auto-build by replacing the default `make all` command by `make elf`. Thus, only
the required `main.elf` file gets generated instead of _all_ executable files (like HDL and memory image files).

[start=1]
. In the project explorer right-click on the project and select **Properties**.
. Select **C/C++ Build** and click on the **Behavior** Tab.
. Update the default targets in the **Workbench Build Behavior** box:
* **Build on resource save:** `elf` (only build the ELF file)
* **Build (Incremental build):** `elf` (only build the ELF file)
* **Clean:** `clean` (only remove project-local build artifacts)
. Click **Apply and Close**.

==== Add NEORV32 Software Framework

[start=1]
. In the project explorer right-click on the project and select **Properties**.
. Expand **C/C++ General**, click on **Paths and Symbols** and highlight **Assembly** under **Languages**.
. In the **Include** tab click **Add...**
* Check the box in front of **Add to all languages** and click on **File System...** and select the NEORV32 library include folder (`path/to/neorv32/sw/lib/include`).
* Click **OK**.
. In the **Include** tab click **Add...**.
* Check the box in front of **Add to all languages** and click on **File System...** and select the NEORV32 commons folder (`path/to/neorv32/sw/common`).
* Click **OK**.
. Click on the *Source Location** tab and click **Link Folder...**.
* Check the box in front of **Link to folder in the system** and click the **Browse** button.
* Select the source folder of the NEORV32 software framework (`path/to/neorv32/sw/lib/source`).
* Click **OK**.
. Click **Apply and Close**.

==== Setup OpenOCD

[start=1]
. In the project explorer right-click on the project and select **Properties**.
. Expand **MCU** and select **OpenOCD Path**.
* Configure the **Executable** and **Folder** according to your openOCD installation.
* Example: `Executable: openocd.exe`
* Example: `Folder: C:\OpenOCD\bin`
* Click **Apply and Close**.
. In the top bar of Eclipse click on the tiny arrow right next to the **Debug** bug icon and select **Debug Configurations**.
. Double-click on **GDB OpenOCD Debugging**; several menu tabs will open on the right.
* In the **Main** tab add `main.elf` to the **C/C++ Application** box.
* In the **Debugger** tab add the NEORV32 OpenOCD script with a `-f` in front of it-
* Example: `Config options: -f ${ProjDirPath}/../../openocd/neorv32.cfg`
* In the **Startup** tab uncheck he box in front of **Initial Reset** and add `monitor reset halt` to the box below.
* In the "Common" tab mark **Shared file** to store the run-configuration right in the project folder instead of the workspace(optional).
* In the **SVD Path** tab add the NEORV32 SVD file (`path/to/neorv32/sw/svd/neorv32.svd`).
. Click **Apply** and then **Close**.

.Default Debug Configuration
[NOTE]
When you start debugging the first time you might need to select the provided debug configuration:
**GDB OpenOCD Debugging > eclipse_example Default**

.Debug Symbols
[IMPORTANT]
For debugging the ELF has to compiled to contain according debug symbols.
Debug symbols are enabled by the project's local makefile: `USER_FLAGS += -ggdb -gdwarf-3`
(this configuration seems to work best for Eclipse - at least for me).

If you need to reconfigure OpenOCD binaries and/or paths:

[start=1]
. right-click on the project in the left view, select **Properties**
. expand **MCU** and select **OpenOCD Path**
. adjust the **Folder** and the **Executable** name if required
. Click **Apply**.

==== Setup Serial Terminal

A serial terminal can be added to Eclipse by installing it as a plugin.
I recommend "TM Terminal" which is already installed in some Eclipse bundles.

Open a TM Terminal serial console:

[start=1]
. Click on **Window > Show View > Terminal** to open the terminal.
. A **Terminal** tab appears on the bottom. Click the tiny screen button on the right (or press Ctrl+Alt+Shift)
to open the terminal configuration.
. Select **Serial Terminal** in **Choose Terminal** and configure the settings according to the processor's
UART configuration.

Installing TM Terminal from the Eclipse market place:

[start=1]
. Click on **Help > Eclipse Marketplace...**.
. Enter "TM Terminal" to the **Find** line and hit enter.
. Select **TM Terminal** from the list and install it.
. After installation restart Eclipse.


=== Eclipse Setup References

* Eclipse help: https://help.eclipse.org/latest/index.jsp
* Importing an existing project into Eclipse: https://help.eclipse.org/latest/index.jsp?topic=%2Forg.eclipse.cdt.doc.user%2Fgetting_started%2Fcdt_w_import.htm
* Eclipse OpenOCD Plug-In: https://eclipse-embed-cdt.github.io/debug/openocd/
