1 files changed, 52 insertions, 4 deletions

diff --git a/src/arch/arm/isa.hh b/src/arch/arm/isa.hh
index a270f046b..905eb0183 100644
--- a/src/arch/arm/isa.hh
+++ b/src/arch/arm/isa.hh
@@ -100,20 +100,69 @@ namespace ArmISA
         readMiscRegNoEffect(int misc_reg)
         {
             assert(misc_reg < NumMiscRegs);
+            if (misc_reg == MISCREG_SPSR) {
+                CPSR cpsr = miscRegs[MISCREG_CPSR];
+                switch (cpsr.mode) {
+                  case MODE_USER:
+                    return miscRegs[MISCREG_SPSR];
+                  case MODE_FIQ:
+                    return miscRegs[MISCREG_SPSR_FIQ];
+                  case MODE_IRQ:
+                    return miscRegs[MISCREG_SPSR_IRQ];
+                  case MODE_SVC:
+                    return miscRegs[MISCREG_SPSR_SVC];
+                  case MODE_MON:
+                    return miscRegs[MISCREG_SPSR_MON];
+                  case MODE_ABORT:
+                    return miscRegs[MISCREG_SPSR_ABT];
+                  case MODE_UNDEFINED:
+                    return miscRegs[MISCREG_SPSR_UND];
+                  default:
+                    return miscRegs[MISCREG_SPSR];
+                }
+            }
             return miscRegs[misc_reg];
         }
 
         MiscReg
         readMiscReg(int misc_reg, ThreadContext *tc)
         {
-            assert(misc_reg < NumMiscRegs);
-            return miscRegs[misc_reg];
+            return readMiscRegNoEffect(misc_reg);
         }
 
         void
         setMiscRegNoEffect(int misc_reg, const MiscReg &val)
         {
             assert(misc_reg < NumMiscRegs);
+            if (misc_reg == MISCREG_SPSR) {
+                CPSR cpsr = miscRegs[MISCREG_CPSR];
+                switch (cpsr.mode) {
+                  case MODE_USER:
+                    miscRegs[MISCREG_SPSR] = val;
+                    return;
+                  case MODE_FIQ:
+                    miscRegs[MISCREG_SPSR_FIQ] = val;
+                    return;
+                  case MODE_IRQ:
+                    miscRegs[MISCREG_SPSR_IRQ] = val;
+                    return;
+                  case MODE_SVC:
+                    miscRegs[MISCREG_SPSR_SVC] = val;
+                    return;
+                  case MODE_MON:
+                    miscRegs[MISCREG_SPSR_MON] = val;
+                    return;
+                  case MODE_ABORT:
+                    miscRegs[MISCREG_SPSR_ABT] = val;
+                    return;
+                  case MODE_UNDEFINED:
+                    miscRegs[MISCREG_SPSR_UND] = val;
+                    return;
+                  default:
+                    miscRegs[MISCREG_SPSR] = val;
+                    return;
+                }
+            }
             miscRegs[misc_reg] = val;
         }
 
@@ -123,8 +172,7 @@ namespace ArmISA
             if (misc_reg == MISCREG_CPSR) {
                 updateRegMap(val);
             }
-            assert(misc_reg < NumMiscRegs);
-            miscRegs[misc_reg] = val;
+            return setMiscRegNoEffect(misc_reg, val);
         }
 
         int