diff --git a/build-gem5 b/build-gem5
index cdc64be..57e773a 100755
--- a/build-gem5
+++ b/build-gem5
@@ -41,7 +41,7 @@ https://github.com/cirosantilli/linux-kernel-module-cheat-regression#gem5-unit-t
 
     def build(self):
         build_dir = self.get_build_dir()
-        binaries_dir = os.path.join(self.env['gem5_system_dir'], 'binaries')
+        binaries_dir = self.env['gem5_system_binaries_dir']
         disks_dir = os.path.join(self.env['gem5_system_dir'], 'disks')
         os.makedirs(binaries_dir, exist_ok=True)
         os.makedirs(disks_dir, exist_ok=True)
diff --git a/common.py b/common.py
index 359f377..3f291c5 100644
--- a/common.py
+++ b/common.py
@@ -852,6 +852,15 @@ Incompatible archs are skipped.
         env['gem5_executable'] = self.get_gem5_target_path(env, 'gem5')
         env['gem5_unit_test_target'] = self.get_gem5_target_path(env, 'unittests')
         env['gem5_system_dir'] = join(env['gem5_build_dir'], 'system')
+        env['gem5_system_binaries_dir'] = join(env['gem5_system_dir'], 'binaries')
+        if self.env['is_arm']:
+            if env['arch'] == 'arm':
+                gem5_bootloader_basename = 'boot.arm'
+            elif env['arch'] == 'aarch64':
+                gem5_bootloader_basename = 'boot.arm64'
+            env['gem5_bootloader'] = join(env['gem5_system_binaries_dir'], gem5_bootloader_basename)
+        else:
+            env['gem5_bootloader'] = None
 
         # gem5 source
         if env['_args_given']['gem5_source_dir']:
diff --git a/run b/run
index dae9ad0..e20d224 100755
--- a/run
+++ b/run
@@ -486,7 +486,6 @@ Extra options to append at the end of the emulator command line.
             gem5_exe_args = self.sh.shlex_split(self.env['gem5_exe_args'])
             if do_trace:
                 gem5_exe_args.extend(['--debug-flags', trace_type, LF])
-            extra_env['M5_PATH'] = self.env['gem5_system_dir']
             # https://stackoverflow.com/questions/52312070/how-to-modify-a-file-under-src-python-and-run-it-without-rebuilding-in-gem5/52312071#52312071
             extra_env['M5_OVERRIDE_PY_SOURCE'] = 'true'
             if self.env['trace_stdout']:
@@ -624,6 +623,9 @@ Extra options to append at the end of the emulator command line.
                             ),
                             LF
                         ])
+                if self.env['gem5_script'] == 'fs' or self.env['gem5_script'] == 'biglittle':
+                    if self.env['gem5_bootloader'] is not None:
+                        cmd.extend(['--bootloader', self.env['gem5_bootloader'], LF])
             cmd.extend(['--mem-size', memory, LF])
             if self.env['gdb_wait']:
                 # https://stackoverflow.com/questions/49296092/how-to-make-gem5-wait-for-gdb-to-connect-to-reliably-break-at-start-kernel-of-th