Run Sim

snitch_cluster.vlt <path_to_binary.elf>

• Example: snitch_cluster.vlt sw/kernels/blas/axpy/build/axpy.elf
• Output: Console output + log files in simulation directory

QuestaSim (Questa)

snitch_cluster.vsim <path_to_binary.elf>

• Example: snitch_cluster.vsim sw/kernels/blas/axpy/build/axpy.elf
• Output: Console output + log files in simulation directory

VCS

snitch_cluster.vcs <path_to_binary.elf>

• Example: snitch_cluster.vcs sw/kernels/blas/axpy/build/axpy.elf
• Output: Console output + log files in simulation directory

Using Make Target (QuestaSim)

For convenience, a Make target alias is provided:

make vsim-run BINARY=<path_to_binary.elf> SIM_DIR=<simulation_directory>

Parameters:

• BINARY: Absolute or relative path to the ELF file (path is relative to simulation directory if relative)
• SIM_DIR: Directory where simulation artifacts will be created (default: test)

Example:

make vsim-run BINARY=$PWD/sw/kernels/blas/axpy/build/axpy.elf SIM_DIR=test

Kernel Verification

To verify results, prepend a verification script to the simulation command:

sw/kernels/blas/axpy/scripts/verify.py snitch_cluster.vlt sw/kernels/misc/tutorial/build/tutorial.elf

Check the exit code to confirm verification success (exit code $0$ means success):

echo $?

Note: Not all kernels provide a verification script. Only add the verification script when simulating a kernel that provides one at the path <kernel_folder>/scripts/.

Verification with the Make Target (QuestaSim)

When using the vsim-run alias, pass the verification script with VERIFY_PY:

make vsim-run BINARY=$PWD/sw/kernels/blas/axpy/build/axpy.elf VERIFY_PY=$PWD/sw/kernels/blas/axpy/scripts/verify.py

The VERIFY_PY path must be absolute or relative to the simulation directory.

Path Resolution

• Simulator binaries can be invoked from any directory
• The target/sim/build/bin/ folder, containing the simulator binaries, is automatically added to the $PATH, so the simulator binaries don't need to be prefixed
• Adapt the relative path to the software binary accordingly, or use absolute paths

Output Files

After simulation completion, the simulation directory will contain:

• Trace files (logs/ subdirectory):

  • One file per core, identified by hart ID
  • .dasm extension (non-human-readable)
  • Can be converted to human-readable format (see annotate-traces skill)

• Simulation-specific artifacts: Log files and outputs from the simulator

Important Notes

• Ensure the software binary was compiled with the same hardware configuration as the simulator binary
• Log files will be overwritten if you run another simulation in the same directory

Related Skills

• build-hw: Build the hardware simulation binary before running simulations
• build-sw: Compile software binaries for simulation (referenced in build-hw)