Debug Neoverse N2 Reference Design with Arm Development Studio
Introduction
Set up your development environment
Debugging SCP/LCP/RSE
Debugging BL1
Debugging BL31
Debugging BL33 / UEFI
Next Steps

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Setting up a connection

Tip

SCP firmware debug uses the -Og argument. This optimizes some variables that make debugging difficult. To replace -Og with -O0, do the following:

  • Navigate to rd-infra/scp/cmake/Toolchain.
  • Modify the appropriate <compiler>-Baremetal.cmake file for your toolchain.

For example, change GNU-Baremetal.cmake:

string(APPEND CMAKE_${language}_FLAGS_DEBUG_INIT "-Og")

to

string(APPEND CMAKE_${language}_FLAGS_DEBUG_INIT "-O0")

After starting the model, click New Debug Connection… from the Debug Control panel.

Image Alt Text:new debug connection alt-textFigure 1. New debug connection

Create a connection name. This can be whatever you prefer.

Image Alt Text:debug connection name alt-textFigure 2. Debug connection name

Next, click on Add a new model….

Image Alt Text:add new model alt-textFigure 3. Add new model

Select the appropriate Model Interface, for example CADI.

Click Browse for model running on local host.

Select the correct model, and click Finish.

Image Alt Text:connect model alt-textFigure 4. Connect model

In the Edit configuration and launch panel, in the Connection tab, select the correct target.

For the SCP code, select ARM_Cortex-M7_1.

Selecting the correct core

For different platforms (e.g., RD-N2, RD-V3, etc.), you will see a list of numbered M7 and M55 cores. Typically, even-numbered M7 cores correspond to the MCP, while odd-numbered cores are assigned to the SCP. Additionally:

  • ARM_Cortex-M55_0 to ARM_Cortex-M55_(N-1) represent LCP cores.
  • ARM_Cortex-M55_N represents the RSE.

To verify core assignments, you can set up alerts (e.g., print statements or store variables), connect to a debugger, and test the configuration.

Image Alt Text:select target alt-textFigure 5. Select target

In the Files panel, select Load Symbols from file, File System, and select the SCP RAMFW ELF file, located at:

rd-infra/scp/output/rdn2/0/scp_ramfw/bin/rdn2-bl2.elf.

RSE debug symbol file location:

rd-infra/tf-m/cmake_build/<plat>/<cfg>/bin/bl1_1.elf
rd-infra/tf-m/cmake_build/<plat>/<cfg>/bin/bl1_2.elf
rd-infra/tf-m/cmake_build/<plat>/<cfg>/bin/bl2.elf

LCP debug symbol file location:

rd-infra/scp/output/<plat>/<cfg>/lcp_ramfw/rdv3-lcp-bl2.elf

Image Alt Text:scp symbols alt-textFigure 6. Load SCP symbols

Select Apply then Debug. The debugger now connects to the model.

Setting breakpoints

Once connected, you can set breakpoints in the source code. This can be done by searching for the function in the Functions tab, double-clicking next to the line number, or in the Command view.

Set a breakpoint at cmn700_discovery(). Continue execution and the code stops at the breakpoint you specify.

break cmn700_discovery
continue

Image Alt Text:scp breakpoint 1 alt-textFigure 7. cmn700_discovery() breakpoint

Set another breakpoint at a debug print statement.

Image Alt Text:scp breakpoint 2 alt-textFigure 8. SCP breakpoint 2

Observe the output in the SCP UART window.

Disconnect from the FVP.

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