diff --git a/src/arch/arm/ArmSystem.py b/src/arch/arm/ArmSystem.py
index 5629ab5114..0e642153b6 100644
--- a/src/arch/arm/ArmSystem.py
+++ b/src/arch/arm/ArmSystem.py
@@ -93,10 +93,6 @@ class ArmSystem(System):
     semihosting = Param.ArmSemihosting(NULL,
         "Enable support for the Arm semihosting by settings this parameter")
 
-    m5ops_base = Param.Addr(0,
-        "Base of the 64KiB PA range used for memory-mapped m5ops. Set to 0 "
-        "to disable.")
-
     dtb_filename = Param.String("",
         "File that contains the Device Tree Blob. Don't use DTB if empty.")
 
diff --git a/src/arch/arm/system.cc b/src/arch/arm/system.cc
index c3c2b8d48b..5c32059f46 100644
--- a/src/arch/arm/system.cc
+++ b/src/arch/arm/system.cc
@@ -75,9 +75,6 @@ ArmSystem::ArmSystem(Params *p)
       _sveVL(p->sve_vl),
       _haveLSE(p->have_lse),
       _havePAN(p->have_pan),
-      _m5opRange(p->m5ops_base ?
-                 RangeSize(p->m5ops_base, 0x10000) :
-                 AddrRange(1, 0)), // Create an empty range if disabled
       semihosting(p->semihosting),
       multiProc(p->multi_proc)
 {
diff --git a/src/arch/arm/system.hh b/src/arch/arm/system.hh
index a9048051ea..90fed14a79 100644
--- a/src/arch/arm/system.hh
+++ b/src/arch/arm/system.hh
@@ -138,12 +138,6 @@ class ArmSystem : public System
     /** True if Priviledge Access Never is implemented */
     const unsigned _havePAN;
 
-    /**
-     * Range for memory-mapped m5 pseudo ops. The range will be
-     * invalid/empty if disabled.
-     */
-    const AddrRange _m5opRange;
-
     /**
      * True if the Semihosting interface is enabled.
      */
diff --git a/src/sim/System.py b/src/sim/System.py
index 619b54ed1d..e49d26a076 100644
--- a/src/sim/System.py
+++ b/src/sim/System.py
@@ -125,5 +125,12 @@ class System(SimObject):
     # Provide list of domains that need to be controlled by the handler
     dvfs_handler = DVFSHandler()
 
+    # SE mode doesn't use the ISA System subclasses, and so we need to set an
+    # ISA specific value in this class directly.
+    m5ops_base = Param.Addr(
+        0xffff0000 if buildEnv['TARGET_ISA'] == 'x86' else 0,
+        "Base of the 64KiB PA range used for memory-mapped m5ops. Set to 0 "
+        "to disable.")
+
     if buildEnv['USE_KVM']:
         kvm_vm = Param.KvmVM(NULL, 'KVM VM (i.e., shared memory domain)')
diff --git a/src/sim/system.cc b/src/sim/system.cc
index 97ebd1d7c0..0cc328c22d 100644
--- a/src/sim/system.cc
+++ b/src/sim/system.cc
@@ -111,6 +111,9 @@ System::System(Params *p)
       numWorkIds(p->num_work_ids),
       thermalModel(p->thermal_model),
       _params(p),
+      _m5opRange(p->m5ops_base ?
+                 RangeSize(p->m5ops_base, 0x10000) :
+                 AddrRange(1, 0)), // Create an empty range if disabled
       totalNumInsts(0),
       redirectPaths(p->redirect_paths)
 {
diff --git a/src/sim/system.hh b/src/sim/system.hh
index 338b126193..6c63b327fd 100644
--- a/src/sim/system.hh
+++ b/src/sim/system.hh
@@ -567,6 +567,12 @@ class System : public SimObject, public PCEventScope
   protected:
     Params *_params;
 
+    /**
+     * Range for memory-mapped m5 pseudo ops. The range will be
+     * invalid/empty if disabled.
+     */
+    const AddrRange _m5opRange;
+
   public:
     System(Params *p);
     ~System();