Debug Arm Zena CSS Reference Software Stack with Arm Development Studio
Introduction
Getting started
Launch the FVP
Configure the model
Create debug connections
Debug RSE from reset
Debug Safety Island code
Debug primary compute and Linux
Next Steps

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Overview

You are now ready to create debug connections for each of the sub-systems within Zena CSS. In this section you will create the connections, which will be subsequently enhanced in the following section. You may prefer to fully set up one such connection before moving to others.

Arm Development Studio has full support for heterogeneous systems such as Zena CSS, and so you can connect to all processors simultaneously.

Create a project for connection files

First, create a project to store these connections (.launch files).

Select File > New… > Project > General > Project, and give it a meaningful name (for example, Connections).

Create an RSE (Cortex-M55) model connection

Runtime Security Engine (RSE) is based on the Cortex-M55 core and is a security subsystem fulfilling the role of Root of Trust.

Select File > New > Model Connection.

Note

You can also use File > New > Other > Arm Debugger > Model Connection, or the Create a debug connection… shortcut in the Debug Control pane.

Specify a connection name (RSE), and associate with the above Connections project. Click Next.

Locate the FVP based on the name you gave it previously (Zena_CSS_FVP). You can use the text filter to locate it quickly.

You will then be presented with the Edit configuration pane. In the Connection tab, scroll down to locate Bare Metal Debug > Arm_Cortex-M55.

As you will be later launching the FVP with the software stack loaded, select Connect to an already running model.

Assuming the same host will be running both the FVP and the debugger, specify the Connection address as the default 127.0.0.1:7100.

Note

127.0.0.1 is the same as localhost, which targets the host running the FVP. For a remote FVP, specify the remote IP address and start the FVP with -A. Port 7100 is the default Iris port and can be adjusted if needed.

Arm Development Studio creates RSE.launch inside the Connections project.

Create a Safety Island (Cortex-R82AE) model connection

The Safety Island is based on the Cortex-R82AE core and manages power, clocks, and CMN control.

Follow the same steps as for RSE, with this change:

In Edit configuration, expand Bare Metal Debug and select Arm_Cortex-R82AE.

Tip

To save time, copy RSE.launch to SI.launch and update the CPU selection to Arm_Cortex-R82AE.

Create Primary compute (Cortex-A720AE) connections

Primary compute comprises four clusters intended to run a rich OS such as Linux. Each cluster has four Cortex-A720AE cores alongside a DSU-120AE DynamIQ Shared Unit.

You will create two connections: one for bare-metal initialization and one with Linux kernel awareness for SMP debug.

Primary init (bare metal, CPU0 only)

Create Primary_init.launch:

  • Select File > New > Model Connection.
  • Select your Zena_CSS_FVP model.
  • In Edit configuration, expand Bare Metal Debug and select ARM_Cortex-A720AE_0 to attach to CPU0 only. This leaves other CPUs running.

Primary Linux (SMP, OS awareness)

Create Primary_Linux.launch for Linux kernel debug with OS awareness:

  • Use File > New > Model Connection.
  • Select your Zena_CSS_FVP model.
  • In Edit configuration, expand Linux Kernel Debug and choose ARM_Cortex-A720AEx16 SMP Cluster 1.
    This connects to all 16 Cortex-A720AE processors described in the FVP. Only cores 0 to 3 are used by the default Linux configuration.

To learn more about OS awareness in Arm Debugger, see the OS awareness documentation .

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