ARM: Implement CPACR register and return Undefined Instruction when FP access is disabled.

11 files changed, 172 insertions, 106 deletions

diff --git a/src/arch/arm/faults.cc b/src/arch/arm/faults.cc
index 793f9d3a4..79973185d 100644
--- a/src/arch/arm/faults.cc
+++ b/src/arch/arm/faults.cc
@@ -159,8 +159,12 @@ Reset::invoke(ThreadContext *tc)
 void
 UndefinedInstruction::invoke(ThreadContext *tc)
 {
+    // If the mnemonic isn't defined this has to be an unknown instruction.
     assert(unknown || mnemonic != NULL);
-    if (unknown) {
+    if (disabled) {
+        panic("Attempted to execute disabled instruction "
+                "'%s' (inst 0x%08x)", mnemonic, machInst);
+    } else if (unknown) {
         panic("Attempted to execute unknown instruction (inst 0x%08x)",
               machInst);
     } else {
diff --git a/src/arch/arm/faults.hh b/src/arch/arm/faults.hh
index f9d25abdf..7dd881435 100644
--- a/src/arch/arm/faults.hh
+++ b/src/arch/arm/faults.hh
@@ -153,12 +153,15 @@ class UndefinedInstruction : public ArmFaultVals<UndefinedInstruction>
     ExtMachInst machInst;
     bool unknown;
     const char *mnemonic;
+    bool disabled;
 
   public:
     UndefinedInstruction(ExtMachInst _machInst,
                          bool _unknown,
-                         const char *_mnemonic = NULL) :
-        machInst(_machInst), unknown(_unknown), mnemonic(_mnemonic)
+                         const char *_mnemonic = NULL,
+                         bool _disabled = false) :
+        machInst(_machInst), unknown(_unknown),
+        mnemonic(_mnemonic), disabled(_disabled)
     {
     }
 
diff --git a/src/arch/arm/insts/static_inst.hh b/src/arch/arm/insts/static_inst.hh
index e98f85a3b..7ea3405af 100644
--- a/src/arch/arm/insts/static_inst.hh
+++ b/src/arch/arm/insts/static_inst.hh
@@ -42,6 +42,7 @@
 #ifndef __ARCH_ARM_INSTS_STATICINST_HH__
 #define __ARCH_ARM_INSTS_STATICINST_HH__
 
+#include "arch/arm/faults.hh"
 #include "base/trace.hh"
 #include "cpu/static_inst.hh"
 
@@ -319,6 +320,16 @@ class ArmStaticInst : public StaticInst
             setNextPC(xc, val);
         }
     }
+
+    inline Fault
+    disabledFault() const
+    {
+#if FULL_SYSTEM
+            return new UndefinedInstruction();
+#else
+            return new UndefinedInstruction(machInst, false, mnemonic, true);
+#endif
+    }
 };
 }
 
diff --git a/src/arch/arm/isa.cc b/src/arch/arm/isa.cc
index ac012fc3c..7991dbfb7 100644
--- a/src/arch/arm/isa.cc
+++ b/src/arch/arm/isa.cc
@@ -66,17 +66,6 @@ ISA::clear()
     miscRegs[MISCREG_SCTLR] = sctlr;
     miscRegs[MISCREG_SCTLR_RST] = sctlr_rst;
 
-
-    /*
-     * Technically this should be 0, but we don't support those
-     * settings.
-     */
-    CPACR cpacr = 0;
-    // Enable CP 10, 11
-    cpacr.cp10 = 0x3;
-    cpacr.cp11 = 0x3;
-    miscRegs[MISCREG_CPACR] = cpacr;
-
     /* Start with an event in the mailbox */
     miscRegs[MISCREG_SEV_MAILBOX] = 1;
 
@@ -278,9 +267,9 @@ ISA::setMiscReg(int misc_reg, const MiscReg &val, ThreadContext *tc)
                 CPACR valCpacr = val;
                 newCpacr.cp10 = valCpacr.cp10;
                 newCpacr.cp11 = valCpacr.cp11;
-                if (newCpacr.cp10 != 0x3 || newCpacr.cp11 != 3) {
-                    panic("Disabling coprocessors isn't implemented.\n");
-                }
+                //XXX d32dis isn't implemented. The manual says whether or not
+                //it works is implementation defined.
+                newCpacr.asedis = valCpacr.asedis;
                 newVal = newCpacr;
             }
             break;
diff --git a/src/arch/arm/isa/insts/fp.isa b/src/arch/arm/isa/insts/fp.isa
index 9748c8a49..51a6b1e4e 100644
--- a/src/arch/arm/isa/insts/fp.isa
+++ b/src/arch/arm/isa/insts/fp.isa
@@ -192,14 +192,16 @@ let {{
     exec_output = ""
 
     vmsrIop = InstObjParams("vmsr", "Vmsr", "FpRegRegOp",
-                            { "code": "MiscDest = Op1;",
+                            { "code": vmsrrsEnabledCheckCode + \
+                                      "MiscDest = Op1;",
                               "predicate_test": predicateTest }, [])
     header_output += FpRegRegOpDeclare.subst(vmsrIop);
     decoder_output += FpRegRegOpConstructor.subst(vmsrIop);
     exec_output += PredOpExecute.subst(vmsrIop);
 
     vmrsIop = InstObjParams("vmrs", "Vmrs", "FpRegRegOp",
-                            { "code": "Dest = MiscOp1;",
+                            { "code": vmsrrsEnabledCheckCode + \
+                                      "Dest = MiscOp1;",
                               "predicate_test": predicateTest }, [])
     header_output += FpRegRegOpDeclare.subst(vmrsIop);
     decoder_output += FpRegRegOpConstructor.subst(vmrsIop);
@@ -213,7 +215,7 @@ let {{
     decoder_output += FpRegRegImmOpConstructor.subst(vmrsApsrIop);
     exec_output += PredOpExecute.subst(vmrsApsrIop);
 
-    vmovImmSCode = '''
+    vmovImmSCode = vfpEnabledCheckCode + '''
         FpDest.uw = bits(imm, 31, 0);
     '''
     vmovImmSIop = InstObjParams("vmov", "VmovImmS", "FpRegImmOp",
@@ -223,7 +225,7 @@ let {{
     decoder_output += FpRegImmOpConstructor.subst(vmovImmSIop);
     exec_output += PredOpExecute.subst(vmovImmSIop);
 
-    vmovImmDCode = '''
+    vmovImmDCode = vfpEnabledCheckCode + '''
         FpDestP0.uw = bits(imm, 31, 0);
         FpDestP1.uw = bits(imm, 63, 32);
     '''
@@ -234,7 +236,7 @@ let {{
     decoder_output += FpRegImmOpConstructor.subst(vmovImmDIop);
     exec_output += PredOpExecute.subst(vmovImmDIop);
 
-    vmovImmQCode = '''
+    vmovImmQCode = vfpEnabledCheckCode + '''
         FpDestP0.uw = bits(imm, 31, 0);
         FpDestP1.uw = bits(imm, 63, 32);
         FpDestP2.uw = bits(imm, 31, 0);
@@ -247,7 +249,7 @@ let {{
     decoder_output += FpRegImmOpConstructor.subst(vmovImmQIop);
     exec_output += PredOpExecute.subst(vmovImmQIop);
 
-    vmovRegSCode = '''
+    vmovRegSCode = vfpEnabledCheckCode + '''
         FpDest.uw = FpOp1.uw;
     '''
     vmovRegSIop = InstObjParams("vmov", "VmovRegS", "FpRegRegOp",
@@ -257,7 +259,7 @@ let {{
     decoder_output += FpRegRegOpConstructor.subst(vmovRegSIop);
     exec_output += PredOpExecute.subst(vmovRegSIop);
 
-    vmovRegDCode = '''
+    vmovRegDCode = vfpEnabledCheckCode + '''
         FpDestP0.uw = FpOp1P0.uw;
         FpDestP1.uw = FpOp1P1.uw;
     '''
@@ -268,7 +270,7 @@ let {{
     decoder_output += FpRegRegOpConstructor.subst(vmovRegDIop);
     exec_output += PredOpExecute.subst(vmovRegDIop);
 
-    vmovRegQCode = '''
+    vmovRegQCode = vfpEnabledCheckCode + '''
         FpDestP0.uw = FpOp1P0.uw;
         FpDestP1.uw = FpOp1P1.uw;
         FpDestP2.uw = FpOp1P2.uw;
@@ -281,7 +283,7 @@ let {{
     decoder_output  += FpRegRegOpConstructor.subst(vmovRegQIop);
     exec_output += PredOpExecute.subst(vmovRegQIop);
 
-    vmovCoreRegBCode = '''
+    vmovCoreRegBCode = vfpEnabledCheckCode + '''
         FpDest.uw = insertBits(FpDest.uw, imm * 8 + 7, imm * 8, Op1.ub);
     '''
     vmovCoreRegBIop = InstObjParams("vmov", "VmovCoreRegB", "FpRegRegImmOp",
@@ -291,7 +293,7 @@ let {{
     decoder_output  += FpRegRegImmOpConstructor.subst(vmovCoreRegBIop);
     exec_output += PredOpExecute.subst(vmovCoreRegBIop);
 
-    vmovCoreRegHCode = '''
+    vmovCoreRegHCode = vfpEnabledCheckCode + '''
         FpDest.uw = insertBits(FpDest.uw, imm * 16 + 15, imm * 16, Op1.uh);
     '''
     vmovCoreRegHIop = InstObjParams("vmov", "VmovCoreRegH", "FpRegRegImmOp",
@@ -301,7 +303,7 @@ let {{
     decoder_output  += FpRegRegImmOpConstructor.subst(vmovCoreRegHIop);
     exec_output += PredOpExecute.subst(vmovCoreRegHIop);
 
-    vmovCoreRegWCode = '''
+    vmovCoreRegWCode = vfpEnabledCheckCode + '''
         FpDest.uw = Op1.uw;
     '''
     vmovCoreRegWIop = InstObjParams("vmov", "VmovCoreRegW", "FpRegRegOp",
@@ -311,7 +313,7 @@ let {{
     decoder_output  += FpRegRegOpConstructor.subst(vmovCoreRegWIop);
     exec_output += PredOpExecute.subst(vmovCoreRegWIop);
 
-    vmovRegCoreUBCode = '''
+    vmovRegCoreUBCode = vfpEnabledCheckCode + '''
         assert(imm < 4);
         Dest = bits(FpOp1.uw, imm * 8 + 7, imm * 8);
     '''
@@ -322,7 +324,7 @@ let {{
     decoder_output  += FpRegRegImmOpConstructor.subst(vmovRegCoreUBIop);
     exec_output += PredOpExecute.subst(vmovRegCoreUBIop);
 
-    vmovRegCoreUHCode = '''
+    vmovRegCoreUHCode = vfpEnabledCheckCode + '''
         assert(imm < 2);
         Dest = bits(FpOp1.uw, imm * 16 + 15, imm * 16);
     '''
@@ -333,7 +335,7 @@ let {{
     decoder_output  += FpRegRegImmOpConstructor.subst(vmovRegCoreUHIop);
     exec_output += PredOpExecute.subst(vmovRegCoreUHIop);
 
-    vmovRegCoreSBCode = '''
+    vmovRegCoreSBCode = vfpEnabledCheckCode + '''
         assert(imm < 4);
         Dest = sext<8>(bits(FpOp1.uw, imm * 8 + 7, imm * 8));
     '''
@@ -344,7 +346,7 @@ let {{
     decoder_output  += FpRegRegImmOpConstructor.subst(vmovRegCoreSBIop);
     exec_output += PredOpExecute.subst(vmovRegCoreSBIop);
 
-    vmovRegCoreSHCode = '''
+    vmovRegCoreSHCode = vfpEnabledCheckCode + '''
         assert(imm < 2);
         Dest = sext<16>(bits(FpOp1.uw, imm * 16 + 15, imm * 16));
     '''
@@ -355,7 +357,7 @@ let {{
     decoder_output  += FpRegRegImmOpConstructor.subst(vmovRegCoreSHIop);
     exec_output += PredOpExecute.subst(vmovRegCoreSHIop);
 
-    vmovRegCoreWCode = '''
+    vmovRegCoreWCode = vfpEnabledCheckCode + '''
         Dest = FpOp1.uw;
     '''
     vmovRegCoreWIop = InstObjParams("vmov", "VmovRegCoreW", "FpRegRegOp",
@@ -365,7 +367,7 @@ let {{
     decoder_output  += FpRegRegOpConstructor.subst(vmovRegCoreWIop);
     exec_output += PredOpExecute.subst(vmovRegCoreWIop);
 
-    vmov2Reg2CoreCode = '''
+    vmov2Reg2CoreCode = vfpEnabledCheckCode + '''
         FpDestP0.uw = Op1.uw;
         FpDestP1.uw = Op2.uw;
     '''
@@ -376,7 +378,7 @@ let {{
     decoder_output  += FpRegRegRegOpConstructor.subst(vmov2Reg2CoreIop);
     exec_output += PredOpExecute.subst(vmov2Reg2CoreIop);
 
-    vmov2Core2RegCode = '''
+    vmov2Core2RegCode = vfpEnabledCheckCode + '''
         Dest.uw = FpOp2P0.uw;
         Op1.uw = FpOp2P1.uw;
     '''
@@ -394,7 +396,7 @@ let {{
     decoder_output = ""
     exec_output = ""
 
-    singleCode = '''
+    singleCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         FpDest = %(op)s;
         Fpscr = fpscr;
@@ -402,7 +404,7 @@ let {{
     singleBinOp = "binaryOp(fpscr, FpOp1, FpOp2," + \
                 "%(func)s, fpscr.fz, fpscr.dn, fpscr.rMode)"
     singleUnaryOp = "unaryOp(fpscr, FpOp1, %(func)s, fpscr.fz, fpscr.rMode)"
-    doubleCode = '''
+    doubleCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         double dest = %(op)s;
         Fpscr = fpscr;
@@ -500,7 +502,7 @@ let {{
     decoder_output = ""
     exec_output = ""
 
-    vmlaSCode = '''
+    vmlaSCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         float mid = binaryOp(fpscr, FpOp1, FpOp2,
                 fpMulS, fpscr.fz, fpscr.dn, fpscr.rMode);
@@ -515,7 +517,7 @@ let {{
     decoder_output  += FpRegRegRegOpConstructor.subst(vmlaSIop);
     exec_output += PredOpExecute.subst(vmlaSIop);
 
-    vmlaDCode = '''
+    vmlaDCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         double mid = binaryOp(fpscr, dbl(FpOp1P0.uw, FpOp1P1.uw),
                                      dbl(FpOp2P0.uw, FpOp2P1.uw),
@@ -534,7 +536,7 @@ let {{
     decoder_output  += FpRegRegRegOpConstructor.subst(vmlaDIop);
     exec_output += PredOpExecute.subst(vmlaDIop);
 
-    vmlsSCode = '''
+    vmlsSCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         float mid = binaryOp(fpscr, FpOp1, FpOp2,
                 fpMulS, fpscr.fz, fpscr.dn, fpscr.rMode);
@@ -549,7 +551,7 @@ let {{
     decoder_output  += FpRegRegRegOpConstructor.subst(vmlsSIop);
     exec_output += PredOpExecute.subst(vmlsSIop);
 
-    vmlsDCode = '''
+    vmlsDCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         double mid = binaryOp(fpscr, dbl(FpOp1P0.uw, FpOp1P1.uw),
                                      dbl(FpOp2P0.uw, FpOp2P1.uw),
@@ -568,7 +570,7 @@ let {{
     decoder_output  += FpRegRegRegOpConstructor.subst(vmlsDIop);
     exec_output += PredOpExecute.subst(vmlsDIop);
 
-    vnmlaSCode = '''
+    vnmlaSCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         float mid = binaryOp(fpscr, FpOp1, FpOp2,
                 fpMulS, fpscr.fz, fpscr.dn, fpscr.rMode);
@@ -583,7 +585,7 @@ let {{
     decoder_output  += FpRegRegRegOpConstructor.subst(vnmlaSIop);
     exec_output += PredOpExecute.subst(vnmlaSIop);
 
-    vnmlaDCode = '''
+    vnmlaDCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         double mid = binaryOp(fpscr, dbl(FpOp1P0.uw, FpOp1P1.uw),
                                      dbl(FpOp2P0.uw, FpOp2P1.uw),
@@ -602,7 +604,7 @@ let {{
     decoder_output  += FpRegRegRegOpConstructor.subst(vnmlaDIop);
     exec_output += PredOpExecute.subst(vnmlaDIop);
 
-    vnmlsSCode = '''
+    vnmlsSCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         float mid = binaryOp(fpscr, FpOp1, FpOp2,
                 fpMulS, fpscr.fz, fpscr.dn, fpscr.rMode);
@@ -617,7 +619,7 @@ let {{
     decoder_output  += FpRegRegRegOpConstructor.subst(vnmlsSIop);
     exec_output += PredOpExecute.subst(vnmlsSIop);
 
-    vnmlsDCode = '''
+    vnmlsDCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         double mid = binaryOp(fpscr, dbl(FpOp1P0.uw, FpOp1P1.uw),
                                      dbl(FpOp2P0.uw, FpOp2P1.uw),
@@ -636,7 +638,7 @@ let {{
     decoder_output  += FpRegRegRegOpConstructor.subst(vnmlsDIop);
     exec_output += PredOpExecute.subst(vnmlsDIop);
 
-    vnmulSCode = '''
+    vnmulSCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         FpDest = -binaryOp(fpscr, FpOp1, FpOp2, fpMulS,
                 fpscr.fz, fpscr.dn, fpscr.rMode);
@@ -649,7 +651,7 @@ let {{
     decoder_output  += FpRegRegRegOpConstructor.subst(vnmulSIop);
     exec_output += PredOpExecute.subst(vnmulSIop);
 
-    vnmulDCode = '''
+    vnmulDCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         double dest = -binaryOp(fpscr, dbl(FpOp1P0.uw, FpOp1P1.uw),
                                        dbl(FpOp2P0.uw, FpOp2P1.uw),
@@ -673,7 +675,7 @@ let {{
     decoder_output = ""
     exec_output = ""
 
-    vcvtUIntFpSCode = '''
+    vcvtUIntFpSCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         VfpSavedState state = prepFpState(fpscr.rMode);
         __asm__ __volatile__("" : "=m" (FpOp1.uw) : "m" (FpOp1.uw));
@@ -689,7 +691,7 @@ let {{
     decoder_output += FpRegRegOpConstructor.subst(vcvtUIntFpSIop);
     exec_output += PredOpExecute.subst(vcvtUIntFpSIop);
 
-    vcvtUIntFpDCode = '''
+    vcvtUIntFpDCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         VfpSavedState state = prepFpState(fpscr.rMode);
         __asm__ __volatile__("" : "=m" (FpOp1P0.uw) : "m" (FpOp1P0.uw));
@@ -707,7 +709,7 @@ let {{
     decoder_output += FpRegRegOpConstructor.subst(vcvtUIntFpDIop);
     exec_output += PredOpExecute.subst(vcvtUIntFpDIop);
 
-    vcvtSIntFpSCode = '''
+    vcvtSIntFpSCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         VfpSavedState state = prepFpState(fpscr.rMode);
         __asm__ __volatile__("" : "=m" (FpOp1.sw) : "m" (FpOp1.sw));
@@ -723,7 +725,7 @@ let {{
     decoder_output += FpRegRegOpConstructor.subst(vcvtSIntFpSIop);
     exec_output += PredOpExecute.subst(vcvtSIntFpSIop);
 
-    vcvtSIntFpDCode = '''
+    vcvtSIntFpDCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         VfpSavedState state = prepFpState(fpscr.rMode);
         __asm__ __volatile__("" : "=m" (FpOp1P0.sw) : "m" (FpOp1P0.sw));
@@ -741,7 +743,7 @@ let {{
     decoder_output += FpRegRegOpConstructor.subst(vcvtSIntFpDIop);
     exec_output += PredOpExecute.subst(vcvtSIntFpDIop);
 
-    vcvtFpUIntSRCode = '''
+    vcvtFpUIntSRCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         VfpSavedState state = prepFpState(fpscr.rMode);
         vfpFlushToZero(fpscr, FpOp1);
@@ -758,7 +760,7 @@ let {{
     decoder_output += FpRegRegOpConstructor.subst(vcvtFpUIntSRIop);
     exec_output += PredOpExecute.subst(vcvtFpUIntSRIop);
 
-    vcvtFpUIntDRCode = '''
+    vcvtFpUIntDRCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         double cOp1 = dbl(FpOp1P0.uw, FpOp1P1.uw);
         vfpFlushToZero(fpscr, cOp1);
@@ -777,7 +779,7 @@ let {{
     decoder_output += FpRegRegOpConstructor.subst(vcvtFpUIntDRIop);
     exec_output += PredOpExecute.subst(vcvtFpUIntDRIop);
 
-    vcvtFpSIntSRCode = '''
+    vcvtFpSIntSRCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         VfpSavedState state = prepFpState(fpscr.rMode);
         vfpFlushToZero(fpscr, FpOp1);
@@ -794,7 +796,7 @@ let {{
     decoder_output += FpRegRegOpConstructor.subst(vcvtFpSIntSRIop);
     exec_output += PredOpExecute.subst(vcvtFpSIntSRIop);
 
-    vcvtFpSIntDRCode = '''
+    vcvtFpSIntDRCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         double cOp1 = dbl(FpOp1P0.uw, FpOp1P1.uw);
         vfpFlushToZero(fpscr, cOp1);
@@ -813,7 +815,7 @@ let {{
     decoder_output += FpRegRegOpConstructor.subst(vcvtFpSIntDRIop);
     exec_output += PredOpExecute.subst(vcvtFpSIntDRIop);
 
-    vcvtFpUIntSCode = '''
+    vcvtFpUIntSCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         vfpFlushToZero(fpscr, FpOp1);
         VfpSavedState state = prepFpState(fpscr.rMode);
@@ -831,7 +833,7 @@ let {{
     decoder_output += FpRegRegOpConstructor.subst(vcvtFpUIntSIop);
     exec_output += PredOpExecute.subst(vcvtFpUIntSIop);
 
-    vcvtFpUIntDCode = '''
+    vcvtFpUIntDCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         double cOp1 = dbl(FpOp1P0.uw, FpOp1P1.uw);
         vfpFlushToZero(fpscr, cOp1);
@@ -851,7 +853,7 @@ let {{
     decoder_output += FpRegRegOpConstructor.subst(vcvtFpUIntDIop);
     exec_output += PredOpExecute.subst(vcvtFpUIntDIop);
 
-    vcvtFpSIntSCode = '''
+    vcvtFpSIntSCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         vfpFlushToZero(fpscr, FpOp1);
         VfpSavedState state = prepFpState(fpscr.rMode);
@@ -869,7 +871,7 @@ let {{
     decoder_output += FpRegRegOpConstructor.subst(vcvtFpSIntSIop);
     exec_output += PredOpExecute.subst(vcvtFpSIntSIop);
 
-    vcvtFpSIntDCode = '''
+    vcvtFpSIntDCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         double cOp1 = dbl(FpOp1P0.uw, FpOp1P1.uw);
         vfpFlushToZero(fpscr, cOp1);
@@ -889,7 +891,7 @@ let {{
     decoder_output += FpRegRegOpConstructor.subst(vcvtFpSIntDIop);
     exec_output += PredOpExecute.subst(vcvtFpSIntDIop);
 
-    vcvtFpSFpDCode = '''
+    vcvtFpSFpDCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         vfpFlushToZero(fpscr, FpOp1);
         VfpSavedState state = prepFpState(fpscr.rMode);
@@ -908,7 +910,7 @@ let {{
     decoder_output += FpRegRegOpConstructor.subst(vcvtFpSFpDIop);
     exec_output += PredOpExecute.subst(vcvtFpSFpDIop);
 
-    vcvtFpDFpSCode = '''
+    vcvtFpDFpSCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         double cOp1 = dbl(FpOp1P0.uw, FpOp1P1.uw);
         vfpFlushToZero(fpscr, cOp1);
@@ -926,7 +928,7 @@ let {{
     decoder_output += FpRegRegOpConstructor.subst(vcvtFpDFpSIop);
     exec_output += PredOpExecute.subst(vcvtFpDFpSIop);
 
-    vcvtFpHTFpSCode = '''
+    vcvtFpHTFpSCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         vfpFlushToZero(fpscr, FpOp1);
         VfpSavedState state = prepFpState(fpscr.rMode);
@@ -944,7 +946,7 @@ let {{
     decoder_output += FpRegRegOpConstructor.subst(vcvtFpHTFpSIop);
     exec_output += PredOpExecute.subst(vcvtFpHTFpSIop);
 
-    vcvtFpHBFpSCode = '''
+    vcvtFpHBFpSCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         VfpSavedState state = prepFpState(fpscr.rMode);
         __asm__ __volatile__("" : "=m" (FpOp1) : "m" (FpOp1));
@@ -961,7 +963,7 @@ let {{
     decoder_output += FpRegRegOpConstructor.subst(vcvtFpHBFpSIop);
     exec_output += PredOpExecute.subst(vcvtFpHBFpSIop);
 
-    vcvtFpSFpHTCode = '''
+    vcvtFpSFpHTCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         vfpFlushToZero(fpscr, FpOp1);
         VfpSavedState state = prepFpState(fpscr.rMode);
@@ -981,7 +983,7 @@ let {{
     decoder_output += FpRegRegOpConstructor.subst(vcvtFpSFpHTIop);
     exec_output += PredOpExecute.subst(vcvtFpSFpHTIop);
 
-    vcvtFpSFpHBCode = '''
+    vcvtFpSFpHBCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         vfpFlushToZero(fpscr, FpOp1);
         VfpSavedState state = prepFpState(fpscr.rMode);
@@ -1001,7 +1003,7 @@ let {{
     decoder_output += FpRegRegOpConstructor.subst(vcvtFpSFpHBIop);
     exec_output += PredOpExecute.subst(vcvtFpSFpHBIop);
 
-    vcmpSCode = '''
+    vcmpSCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         vfpFlushToZero(fpscr, FpDest, FpOp1);
         if (FpDest == FpOp1) {
@@ -1029,7 +1031,7 @@ let {{
     decoder_output += FpRegRegOpConstructor.subst(vcmpSIop);
     exec_output += PredOpExecute.subst(vcmpSIop);
 
-    vcmpDCode = '''
+    vcmpDCode = vfpEnabledCheckCode + '''
         double cOp1 = dbl(FpOp1P0.uw, FpOp1P1.uw);
         double cDest = dbl(FpDestP0.uw, FpDestP1.uw);
         FPSCR fpscr = Fpscr;
@@ -1059,7 +1061,7 @@ let {{
     decoder_output += FpRegRegOpConstructor.subst(vcmpDIop);
     exec_output += PredOpExecute.subst(vcmpDIop);
 
-    vcmpZeroSCode = '''
+    vcmpZeroSCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         vfpFlushToZero(fpscr, FpDest);
         // This only handles imm == 0 for now.
@@ -1087,7 +1089,7 @@ let {{
     decoder_output += FpRegImmOpConstructor.subst(vcmpZeroSIop);
     exec_output += PredOpExecute.subst(vcmpZeroSIop);
 
-    vcmpZeroDCode = '''
+    vcmpZeroDCode = vfpEnabledCheckCode + '''
         // This only handles imm == 0 for now.
         assert(imm == 0);
         double cDest = dbl(FpDestP0.uw, FpDestP1.uw);
@@ -1116,7 +1118,7 @@ let {{
     decoder_output += FpRegImmOpConstructor.subst(vcmpZeroDIop);
     exec_output += PredOpExecute.subst(vcmpZeroDIop);
 
-    vcmpeSCode = '''
+    vcmpeSCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         vfpFlushToZero(fpscr, FpDest, FpOp1);
         if (FpDest == FpOp1) {
@@ -1138,7 +1140,7 @@ let {{
     decoder_output += FpRegRegOpConstructor.subst(vcmpeSIop);
     exec_output += PredOpExecute.subst(vcmpeSIop);
 
-    vcmpeDCode = '''
+    vcmpeDCode = vfpEnabledCheckCode + '''
         double cOp1 = dbl(FpOp1P0.uw, FpOp1P1.uw);
         double cDest = dbl(FpDestP0.uw, FpDestP1.uw);
         FPSCR fpscr = Fpscr;
@@ -1162,7 +1164,7 @@ let {{
     decoder_output += FpRegRegOpConstructor.subst(vcmpeDIop);
     exec_output += PredOpExecute.subst(vcmpeDIop);
 
-    vcmpeZeroSCode = '''
+    vcmpeZeroSCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         vfpFlushToZero(fpscr, FpDest);
         if (FpDest == imm) {
@@ -1184,7 +1186,7 @@ let {{
     decoder_output += FpRegImmOpConstructor.subst(vcmpeZeroSIop);
     exec_output += PredOpExecute.subst(vcmpeZeroSIop);
 
-    vcmpeZeroDCode = '''
+    vcmpeZeroDCode = vfpEnabledCheckCode + '''
         double cDest = dbl(FpDestP0.uw, FpDestP1.uw);
         FPSCR fpscr = Fpscr;
         vfpFlushToZero(fpscr, cDest);
@@ -1214,7 +1216,7 @@ let {{
     decoder_output = ""
     exec_output = ""
 
-    vcvtFpSFixedSCode = '''
+    vcvtFpSFixedSCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         vfpFlushToZero(fpscr, FpOp1);
         VfpSavedState state = prepFpState(fpscr.rMode);
@@ -1231,7 +1233,7 @@ let {{
     decoder_output += FpRegRegImmOpConstructor.subst(vcvtFpSFixedSIop);
     exec_output += PredOpExecute.subst(vcvtFpSFixedSIop);
 
-    vcvtFpSFixedDCode = '''
+    vcvtFpSFixedDCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         double cOp1 = dbl(FpOp1P0.uw, FpOp1P1.uw);
         vfpFlushToZero(fpscr, cOp1);
@@ -1251,7 +1253,7 @@ let {{
     decoder_output += FpRegRegImmOpConstructor.subst(vcvtFpSFixedDIop);
     exec_output += PredOpExecute.subst(vcvtFpSFixedDIop);
 
-    vcvtFpUFixedSCode = '''
+    vcvtFpUFixedSCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         vfpFlushToZero(fpscr, FpOp1);
         VfpSavedState state = prepFpState(fpscr.rMode);
@@ -1268,7 +1270,7 @@ let {{
     decoder_output += FpRegRegImmOpConstructor.subst(vcvtFpUFixedSIop);
     exec_output += PredOpExecute.subst(vcvtFpUFixedSIop);
 
-    vcvtFpUFixedDCode = '''
+    vcvtFpUFixedDCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         double cOp1 = dbl(FpOp1P0.uw, FpOp1P1.uw);
         vfpFlushToZero(fpscr, cOp1);
@@ -1288,7 +1290,7 @@ let {{
     decoder_output += FpRegRegImmOpConstructor.subst(vcvtFpUFixedDIop);
     exec_output += PredOpExecute.subst(vcvtFpUFixedDIop);
 
-    vcvtSFixedFpSCode = '''
+    vcvtSFixedFpSCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         VfpSavedState state = prepFpState(fpscr.rMode);
         __asm__ __volatile__("" : "=m" (FpOp1.sw) : "m" (FpOp1.sw));
@@ -1304,7 +1306,7 @@ let {{
     decoder_output += FpRegRegImmOpConstructor.subst(vcvtSFixedFpSIop);
     exec_output += PredOpExecute.subst(vcvtSFixedFpSIop);
 
-    vcvtSFixedFpDCode = '''
+    vcvtSFixedFpDCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         uint64_t mid = ((uint64_t)FpOp1P0.uw | ((uint64_t)FpOp1P1.uw << 32));
         VfpSavedState state = prepFpState(fpscr.rMode);
@@ -1323,7 +1325,7 @@ let {{
     decoder_output += FpRegRegImmOpConstructor.subst(vcvtSFixedFpDIop);
     exec_output += PredOpExecute.subst(vcvtSFixedFpDIop);
 
-    vcvtUFixedFpSCode = '''
+    vcvtUFixedFpSCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         VfpSavedState state = prepFpState(fpscr.rMode);
         __asm__ __volatile__("" : "=m" (FpOp1.uw) : "m" (FpOp1.uw));
@@ -1339,7 +1341,7 @@ let {{
     decoder_output += FpRegRegImmOpConstructor.subst(vcvtUFixedFpSIop);
     exec_output += PredOpExecute.subst(vcvtUFixedFpSIop);
 
-    vcvtUFixedFpDCode = '''
+    vcvtUFixedFpDCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         uint64_t mid = ((uint64_t)FpOp1P0.uw | ((uint64_t)FpOp1P1.uw << 32));
         VfpSavedState state = prepFpState(fpscr.rMode);
@@ -1358,7 +1360,7 @@ let {{
     decoder_output += FpRegRegImmOpConstructor.subst(vcvtUFixedFpDIop);
     exec_output += PredOpExecute.subst(vcvtUFixedFpDIop);
 
-    vcvtFpSHFixedSCode = '''
+    vcvtFpSHFixedSCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         vfpFlushToZero(fpscr, FpOp1);
         VfpSavedState state = prepFpState(fpscr.rMode);
@@ -1376,7 +1378,7 @@ let {{
     decoder_output += FpRegRegImmOpConstructor.subst(vcvtFpSHFixedSIop);
     exec_output += PredOpExecute.subst(vcvtFpSHFixedSIop);
 
-    vcvtFpSHFixedDCode = '''
+    vcvtFpSHFixedDCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         double cOp1 = dbl(FpOp1P0.uw, FpOp1P1.uw);
         vfpFlushToZero(fpscr, cOp1);
@@ -1397,7 +1399,7 @@ let {{
     decoder_output += FpRegRegImmOpConstructor.subst(vcvtFpSHFixedDIop);
     exec_output += PredOpExecute.subst(vcvtFpSHFixedDIop);
 
-    vcvtFpUHFixedSCode = '''
+    vcvtFpUHFixedSCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         vfpFlushToZero(fpscr, FpOp1);
         VfpSavedState state = prepFpState(fpscr.rMode);
@@ -1415,7 +1417,7 @@ let {{
     decoder_output += FpRegRegImmOpConstructor.subst(vcvtFpUHFixedSIop);
     exec_output += PredOpExecute.subst(vcvtFpUHFixedSIop);
 
-    vcvtFpUHFixedDCode = '''
+    vcvtFpUHFixedDCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         double cOp1 = dbl(FpOp1P0.uw, FpOp1P1.uw);
         vfpFlushToZero(fpscr, cOp1);
@@ -1436,7 +1438,7 @@ let {{
     decoder_output += FpRegRegImmOpConstructor.subst(vcvtFpUHFixedDIop);
     exec_output += PredOpExecute.subst(vcvtFpUHFixedDIop);
 
-    vcvtSHFixedFpSCode = '''
+    vcvtSHFixedFpSCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         VfpSavedState state = prepFpState(fpscr.rMode);
         __asm__ __volatile__("" : "=m" (FpOp1.sh) : "m" (FpOp1.sh));
@@ -1453,7 +1455,7 @@ let {{
     decoder_output += FpRegRegImmOpConstructor.subst(vcvtSHFixedFpSIop);
     exec_output += PredOpExecute.subst(vcvtSHFixedFpSIop);
 
-    vcvtSHFixedFpDCode = '''
+    vcvtSHFixedFpDCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         uint64_t mid = ((uint64_t)FpOp1P0.uw | ((uint64_t)FpOp1P1.uw << 32));
         VfpSavedState state = prepFpState(fpscr.rMode);
@@ -1473,7 +1475,7 @@ let {{
     decoder_output += FpRegRegImmOpConstructor.subst(vcvtSHFixedFpDIop);
     exec_output += PredOpExecute.subst(vcvtSHFixedFpDIop);
 
-    vcvtUHFixedFpSCode = '''
+    vcvtUHFixedFpSCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         VfpSavedState state = prepFpState(fpscr.rMode);
         __asm__ __volatile__("" : "=m" (FpOp1.uh) : "m" (FpOp1.uh));
@@ -1490,7 +1492,7 @@ let {{
     decoder_output += FpRegRegImmOpConstructor.subst(vcvtUHFixedFpSIop);
     exec_output += PredOpExecute.subst(vcvtUHFixedFpSIop);
 
-    vcvtUHFixedFpDCode = '''
+    vcvtUHFixedFpDCode = vfpEnabledCheckCode + '''
         FPSCR fpscr = Fpscr;
         uint64_t mid = ((uint64_t)FpOp1P0.uw | ((uint64_t)FpOp1P1.uw << 32));
         VfpSavedState state = prepFpState(fpscr.rMode);
diff --git a/src/arch/arm/isa/insts/neon.isa b/src/arch/arm/isa/insts/neon.isa
index b629c6fe8..1568b755b 100644
--- a/src/arch/arm/isa/insts/neon.isa
+++ b/src/arch/arm/isa/insts/neon.isa
@@ -620,6 +620,13 @@ output exec {{
 }};
 
 let {{
+    simdEnabledCheckCode = '''
+        if (!neonEnabled(Cpacr, Cpsr, Fpexc))
+            return disabledFault();
+    '''
+}};
+
+let {{
 
     header_output = ""
     exec_output = ""
@@ -634,7 +641,7 @@ let {{
     def threeEqualRegInst(name, Name, types, rCount, op,
                           readDest=False, pairwise=False):
         global header_output, exec_output
-        eWalkCode = '''
+        eWalkCode = simdEnabledCheckCode + '''
         RegVect srcReg1, srcReg2, destReg;
         '''
         for reg in range(rCount):
@@ -694,7 +701,7 @@ let {{
     def threeEqualRegInstFp(name, Name, types, rCount, op,
                             readDest=False, pairwise=False, toInt=False):
         global header_output, exec_output
-        eWalkCode = '''
+        eWalkCode = simdEnabledCheckCode + '''
         typedef FloatReg FloatVect[rCount];
         FloatVect srcRegs1, srcRegs2;
         '''
@@ -789,7 +796,7 @@ let {{
         if bigDest:
             destCnt = 4
             destPrefix = 'Big'
-        eWalkCode = '''
+        eWalkCode = simdEnabledCheckCode + '''
             %sRegVect srcReg1;
             %sRegVect srcReg2;
             %sRegVect destReg;
@@ -852,7 +859,7 @@ let {{
 
     def twoEqualRegInst(name, Name, types, rCount, op, readDest=False):
         global header_output, exec_output
-        eWalkCode = '''
+        eWalkCode = simdEnabledCheckCode + '''
         RegVect srcReg1, srcReg2, destReg;
         '''
         for reg in range(rCount):
@@ -897,7 +904,7 @@ let {{
     def twoRegLongInst(name, Name, types, op, readDest=False):
         global header_output, exec_output
         rCount = 2
-        eWalkCode = '''
+        eWalkCode = simdEnabledCheckCode + '''
         RegVect srcReg1, srcReg2;
         BigRegVect destReg;
         '''
@@ -943,7 +950,7 @@ let {{
 
     def twoEqualRegInstFp(name, Name, types, rCount, op, readDest=False):
         global header_output, exec_output
-        eWalkCode = '''
+        eWalkCode = simdEnabledCheckCode + '''
         typedef FloatReg FloatVect[rCount];
         FloatVect srcRegs1, srcRegs2, destRegs;
         '''
@@ -989,7 +996,7 @@ let {{
     def twoRegShiftInst(name, Name, types, rCount, op,
             readDest=False, toInt=False, fromInt=False):
         global header_output, exec_output
-        eWalkCode = '''
+        eWalkCode = simdEnabledCheckCode + '''
         RegVect srcRegs1, destRegs;
         '''
         for reg in range(rCount):
@@ -1044,7 +1051,7 @@ let {{
 
     def twoRegNarrowShiftInst(name, Name, types, op, readDest=False):
         global header_output, exec_output
-        eWalkCode = '''
+        eWalkCode = simdEnabledCheckCode + '''
         BigRegVect srcReg1;
         RegVect destReg;
         '''
@@ -1087,7 +1094,7 @@ let {{
 
     def twoRegLongShiftInst(name, Name, types, op, readDest=False):
         global header_output, exec_output
-        eWalkCode = '''
+        eWalkCode = simdEnabledCheckCode + '''
         RegVect srcReg1;
         BigRegVect destReg;
         '''
@@ -1130,7 +1137,7 @@ let {{
 
     def twoRegMiscInst(name, Name, types, rCount, op, readDest=False):
         global header_output, exec_output
-        eWalkCode = '''
+        eWalkCode = simdEnabledCheckCode + '''
         RegVect srcReg1, destReg;
         '''
         for reg in range(rCount):
@@ -1172,7 +1179,7 @@ let {{
 
     def twoRegMiscScInst(name, Name, types, rCount, op, readDest=False):
         global header_output, exec_output
-        eWalkCode = '''
+        eWalkCode = simdEnabledCheckCode + '''
         RegVect srcReg1, destReg;
         '''
         for reg in range(rCount):
@@ -1213,7 +1220,7 @@ let {{
 
     def twoRegMiscScramble(name, Name, types, rCount, op, readDest=False):
         global header_output, exec_output
-        eWalkCode = '''
+        eWalkCode = simdEnabledCheckCode + '''
         RegVect srcReg1, destReg;
         '''
         for reg in range(rCount):
@@ -1248,7 +1255,7 @@ let {{
     def twoRegMiscInstFp(name, Name, types, rCount, op,
             readDest=False, toInt=False):
         global header_output, exec_output
-        eWalkCode = '''
+        eWalkCode = simdEnabledCheckCode + '''
         typedef FloatReg FloatVect[rCount];
         FloatVect srcRegs1;
         '''
@@ -1312,7 +1319,7 @@ let {{
 
     def twoRegCondenseInst(name, Name, types, rCount, op, readDest=False):
         global header_output, exec_output
-        eWalkCode = '''
+        eWalkCode = simdEnabledCheckCode + '''
         RegVect srcRegs;
         BigRegVect destReg;
         '''
@@ -1355,7 +1362,7 @@ let {{
 
     def twoRegNarrowMiscInst(name, Name, types, op, readDest=False):
         global header_output, exec_output
-        eWalkCode = '''
+        eWalkCode = simdEnabledCheckCode + '''
         BigRegVect srcReg1;
         RegVect destReg;
         '''
@@ -1398,7 +1405,7 @@ let {{
 
     def oneRegImmInst(name, Name, types, rCount, op, readDest=False):
         global header_output, exec_output
-        eWalkCode = '''
+        eWalkCode = simdEnabledCheckCode + '''
         RegVect destReg;
         '''
         if readDest:
@@ -1435,7 +1442,7 @@ let {{
 
     def twoRegLongMiscInst(name, Name, types, op, readDest=False):
         global header_output, exec_output
-        eWalkCode = '''
+        eWalkCode = simdEnabledCheckCode + '''
         RegVect srcReg1;
         BigRegVect destReg;
         '''
diff --git a/src/arch/arm/isa/operands.isa b/src/arch/arm/isa/operands.isa
index 5490a28e0..7b2b50290 100644
--- a/src/arch/arm/isa/operands.isa
+++ b/src/arch/arm/isa/operands.isa
@@ -205,6 +205,7 @@ def operands {{
     'Fpsr': ('ControlReg', 'uw', 'MISCREG_FPSR', None, 2),
     'Fpsid': ('ControlReg', 'uw', 'MISCREG_FPSID', None, 2),
     'Fpscr': ('ControlReg', 'uw', 'MISCREG_FPSCR', None, 2),
+    'Cpacr': ('ControlReg', 'uw', 'MISCREG_CPACR', (None, None, 'IsControl'), 2),
     'Fpexc': ('ControlReg', 'uw', 'MISCREG_FPEXC', None, 2),
     'Sctlr': ('ControlReg', 'uw', 'MISCREG_SCTLR', None, 2),
     'SevMailbox': ('ControlReg', 'uw', 'MISCREG_SEV_MAILBOX', None, 2),
diff --git a/src/arch/arm/isa/templates/vfp.isa b/src/arch/arm/isa/templates/vfp.isa
index b0443c734..5de52738c 100644
--- a/src/arch/arm/isa/templates/vfp.isa
+++ b/src/arch/arm/isa/templates/vfp.isa
@@ -37,6 +37,18 @@
 //
 // Authors: Gabe Black
 
+let {{
+    vfpEnabledCheckCode = '''
+        if (!vfpEnabled(Cpacr, Cpsr, Fpexc))
+            return disabledFault();
+    '''
+
+    vmsrrsEnabledCheckCode = '''
+        if (!vfpEnabled(Cpacr, Cpsr))
+            return disabledFault();
+    '''
+}};
+
 def template FpRegRegOpDeclare {{
 class %(class_name)s : public %(base_class)s
 {
diff --git a/src/arch/arm/miscregs.hh b/src/arch/arm/miscregs.hh
index 86a11d508..453893908 100644
--- a/src/arch/arm/miscregs.hh
+++ b/src/arch/arm/miscregs.hh
@@ -354,6 +354,12 @@ namespace ArmISA
         Bitfield<31> n;
     EndBitUnion(FPSCR)
 
+    BitUnion32(FPEXC)
+        Bitfield<31> ex;
+        Bitfield<30> en;
+        Bitfield<29, 0> subArchDefined;
+    EndBitUnion(FPEXC)
+
     BitUnion32(MVFR0)
         Bitfield<3, 0> advSimdRegisters;
         Bitfield<7, 4> singlePrecision;
diff --git a/src/arch/arm/process.cc b/src/arch/arm/process.cc
index e7748ad50..e8dda1af0 100644
--- a/src/arch/arm/process.cc
+++ b/src/arch/arm/process.cc
@@ -78,6 +78,18 @@ ArmLiveProcess::startup()
 {
     LiveProcess::startup();
     argsInit(MachineBytes, VMPageSize);
+    for (int i = 0; i < contextIds.size(); i++) {
+        ThreadContext * tc = system->getThreadContext(contextIds[i]);
+        CPACR cpacr = tc->readMiscReg(MISCREG_CPACR);
+        // Enable the floating point coprocessors.
+        cpacr.cp10 = 0x3;
+        cpacr.cp11 = 0x3;
+        tc->setMiscReg(MISCREG_CPACR, cpacr);
+        // Generically enable floating point support.
+        FPEXC fpexc = tc->readMiscReg(MISCREG_FPEXC);
+        fpexc.en = 1;
+        tc->setMiscReg(MISCREG_FPEXC, fpexc);
+    }
 }
 
 void
diff --git a/src/arch/arm/utility.hh b/src/arch/arm/utility.hh
index 65c94926e..4256aa047 100644
--- a/src/arch/arm/utility.hh
+++ b/src/arch/arm/utility.hh
@@ -146,6 +146,25 @@ namespace ArmISA {
         return !inUserMode(tc);
     }
 
+    static inline bool
+    vfpEnabled(CPACR cpacr, CPSR cpsr)
+    {
+        return cpacr.cp10 == 0x3 ||
+            (cpacr.cp10 == 0x2 && inPrivilegedMode(cpsr));
+    }
+
+    static inline bool
+    vfpEnabled(CPACR cpacr, CPSR cpsr, FPEXC fpexc)
+    {
+        return fpexc.en && vfpEnabled(cpacr, cpsr);
+    }
+
+    static inline bool
+    neonEnabled(CPACR cpacr, CPSR cpsr, FPEXC fpexc)
+    {
+        return !cpacr.asedis && vfpEnabled(cpacr, cpsr, fpexc);
+    }
+
 uint64_t getArgument(ThreadContext *tc, int number, bool fp);
     
 Fault setCp15Register(uint32_t &Rd, int CRn, int opc1, int CRm, int opc2);