diff --git a/util/sim/simulate.py b/util/sim/simulate.py
index 9387ab1916..a1466dc167 100755
--- a/util/sim/simulate.py
+++ b/util/sim/simulate.py
@@ -19,7 +19,7 @@
 BANSHEE_CFG = 'src/banshee.yaml'
 
 # Tool settings
-SIMULATORS = ['vsim', 'banshee', 'verilator', 'vcs']
+SIMULATORS = ['vsim', 'banshee', 'verilator', 'vcs', 'other']
 DEFAULT_SIMULATOR = SIMULATORS[0]
 SIMULATOR_BINS = {
     'vsim': 'bin/snitch_cluster.vsim',
@@ -81,6 +81,51 @@ def check_exit_code(test, exit_code):
         return exit_code
 
 
+def run_simulation(cmd, simulator, test):
+    # Defaults
+    result = 1
+
+    # Spawn simulation subprocess
+    p = subprocess.Popen(cmd, shell=True, stdout=subprocess.PIPE, universal_newlines=True)
+
+    # Poll simulation subprocess and log its output
+    while p.poll() is None:
+        line = p.stdout.readline()
+        print(line, end='', flush=True)
+
+        # When simulating with vsim or vcs, we need to parse the simulation
+        # log to catch the application's return code
+        if simulator in ['vsim', 'vcs']:
+            # Capture success
+            regex_success = r'\[SUCCESS\] Program finished successfully'
+            match_success = re.search(regex_success, line)
+            if match_success:
+                result = 0
+            else:
+                regex_fail = r'\[FAILURE\] Finished with exit code\s+(\d+)'
+                match = re.search(regex_fail, line)
+                if match:
+                    exit_code = match.group(1)
+                    result = check_exit_code(test, exit_code)
+
+    # Check if the subprocess terminated correctly
+    exit_code = p.poll()
+    # In Banshee and Verilator the exit code of the Snitch binary is returned
+    # through the exit code of the simulation command
+    if simulator in ['banshee', 'verilator']:
+        result = check_exit_code(test, exit_code)
+    # For custom commands the return code is that of the command
+    elif simulator == 'other':
+        result = exit_code
+    # For standard simulation commands the simulated Snitch binary exit
+    # code is overriden only if the simulator failed
+    else:
+        if exit_code != 0:
+            result = exit_code
+
+    return result
+
+
 def run_test(test, args):
     # Extract args
     simulator = args.simulator
@@ -94,59 +139,31 @@ def run_test(test, args):
             return 0
 
     # Construct path to executable
-    elf = Path(testlist).absolute().parent / Path(test['elf'])
+    elf = Path(test['elf'])
+    if testlist:
+        elf = Path(testlist).absolute().parent / elf
     cprint(f'Run test {colored(elf, "cyan")}', attrs=["bold"])
 
     # Construct simulation command (override only supported for RTL)
     if 'cmd' in test and simulator != 'banshee':
         cmd = test['cmd']
+        cmd = cmd.format(sim_bin=sim_bin, elf=elf, simulator=simulator)
+        simulator = 'other'
     else:
         cmd = SIMULATOR_CMDS[simulator]
-    cmd = cmd.format(sim_bin=sim_bin, elf=elf)
+        cmd = cmd.format(sim_bin=sim_bin, elf=elf)
     print(f'$ {cmd}', flush=True)
 
-    # Run test
+    # Run simulation
     result = 0
     if not dry_run:
-        result = 1
-
-        # When simulating with vsim or vcs, we need to parse the simulation
-        # log to catch the application's return code
-        if simulator in ['vsim', 'vcs']:
-            p = subprocess.Popen(cmd, shell=True, stdout=subprocess.PIPE,
-                                 text=True)
-
-            while p.poll() is None:
-                line = p.stdout.readline()
-                print(line, end='', flush=True)
-
-                # Capture success
-                regex_success = r'\[SUCCESS\] Program finished successfully'
-                match_success = re.search(regex_success, line)
-                if match_success:
-                    result = 0
-                else:
-                    regex_fail = r'\[FAILURE\] Finished with exit code\s+(\d+)'
-                    match = re.search(regex_fail, line)
-                    if match:
-                        exit_code = match.group(1)
-                        result = check_exit_code(test, exit_code)
-
-            # Check if the subprocess terminated correctly
-            if p.poll() != 0:
-                result = p.poll()
+        result = run_simulation(cmd, simulator, test)
 
-        else:
-            p = subprocess.Popen(cmd, shell=True)
-            p.wait()
-            exit_code = p.returncode
-            result = check_exit_code(test, exit_code)
-
-        # Report failure or success
-        if result != 0:
-            cprint(f'{elf} test failed', 'red', attrs=['bold'], flush=True)
-        else:
-            cprint(f'{elf} test passed', 'green', attrs=['bold'], flush=True)
+    # Report failure or success
+    if result != 0:
+        cprint(f'{elf} test failed', 'red', attrs=['bold'], flush=True)
+    else:
+        cprint(f'{elf} test passed', 'green', attrs=['bold'], flush=True)
 
     return result