Debug Trusted Firmware-A and the Linux kernel on Arm FVP with Arm Development Studio
Introduction
Introduction to Arm Fixed Virtual Platforms (FVPs)
Configure Trusted Firmware-A build flags to include cpu_ops support
Modify the device tree for CPU FVPs
Run the Linux software stack on an FVP
Debug the software stack
Next steps

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Ensure the device tree matches your FVP model

To run Linux on Arm CPU FVPs, you need to adjust the device tree to match the hardware features of these platforms. This involves removing unsupported nodes, such as the System Memory Management Unit (SMMU) and Peripheral Component Interconnect (PCI), and ensuring that the CPU affinity values are set correctly.

Remove PCI and SMMU nodes

CPU FVPs don’t support PCI or SMMU. If you leave these nodes in the device tree, Linux will crash at boot with a kernel panic.

So to workaround this, you need to remove PCI and SMMU nodes:

Open the device tree file in a text editor:

    

        
        
vim linux/arch/arm64/boot/dts/arm/fvp-base-revc.dts

Remove the following nodes:

  • pci@40000000
  • iommu@2b400000
Warning

If you skip this step, you might encounter an error like:

    

        
        Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b

Set CPU affinity values

Each FVP model uses specific CPU affinity values. If these don’t match the values in the device tree, some of the CPU cores won’t boot.

Find the correct affinities:

    

        
        
FVP_Base_Cortex-A55x4 -l | grep pctl.CPU-affinities

Example output:

    

        
        pctl.CPU-affinities=0.0.0.0, 0.0.1.0, 0.0.2.0, 0.0.3.0

Convert each to hex for the reg field:

    

        
        0x0, 0x0100, 0x0200, 0x0300

Update the CPU nodes in your device tree file to use these reg values.

Tip

To avoid boot errors such as psci: failed to boot CPUx (-22), make sure every cpu@xxx entry matches the FVP layout.

Rebuild Linux

After editing the device tree, rebuild Linux:

    

        
        
./build-scripts/build-linux.sh -p aemfvp-a -f busybox clean
./build-scripts/build-linux.sh -p aemfvp-a -f busybox build
./build-scripts/aemfvp-a/build-test-busybox.sh -p aemfvp-a package

This regenerates the image with the updated device tree, ready for use with your FVP.

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