Debug: Implement getArgument() and function skipping for ARM.

In the process make add skipFuction() to handle isa specific function skipping
instead of ifdefs and other ugliness. For almost all ABIs, 64 bit arguments can
only start in even registers.  Size is now passed to getArgument() so that 32
bit systems can make decisions about register selection for 64 bit arguments.
The number argument is now passed by reference because getArgument() will need
to change it based on the size of the argument and the current argument number.

For ARM, if the argument number is odd and a 64-bit register is requested the
number must first be incremented to because all 64 bit arguments are passed
in an even argument register. Then the number will be incremented again to
access both halves of the argument.

src/arch/alpha/utility.cc

@@ -40,7 +40,7 @@
 namespace AlphaISA {
 
 uint64_t
-getArgument(ThreadContext *tc, int number, bool fp)
+getArgument(ThreadContext *tc, int &number, uint8_t size, bool fp)
 {
 #if FULL_SYSTEM
     const int NumArgumentRegs = 6;
@@ -96,5 +96,14 @@ copyMiscRegs(ThreadContext *src, ThreadContext *dest)
     copyIprs(src, dest);
 }
 
+void
+skipFunction(ThreadContext *tc)
+{
+    Addr newpc = tc->readIntReg(ReturnAddressReg);
+    tc->setPC(newpc);
+    tc->setNextPC(tc->readPC() + sizeof(TheISA::MachInst));
+}
+
+
 } // namespace AlphaISA
 

src/arch/alpha/utility.hh

@@ -41,7 +41,7 @@
 
 namespace AlphaISA {
 
-uint64_t getArgument(ThreadContext *tc, int number, bool fp);
+uint64_t getArgument(ThreadContext *tc, int &number, uint8_t size,  bool fp);
 
 inline bool
 inUserMode(ThreadContext *tc)
@@ -94,6 +94,7 @@ void copyRegs(ThreadContext *src, ThreadContext *dest);
 
 void copyMiscRegs(ThreadContext *src, ThreadContext *dest);
 
+void skipFunction(ThreadContext *tc);
 } // namespace AlphaISA
 
 #endif // __ARCH_ALPHA_UTILITY_HH__

src/arch/arm/system.hh

@@ -67,7 +67,10 @@ class ArmSystem : public System
     
     virtual Addr fixFuncEventAddr(Addr addr)
     {
-        //XXX This may eventually have to do something useful.
+        // Remove the low bit that thumb symbols have set
+        // but that aren't actually odd aligned
+        if (addr & 0x1)
+            return (addr & ~1) | PcTBit;
         return addr;
     }
 };

src/arch/arm/utility.cc

@@ -42,6 +42,10 @@
 #include "arch/arm/utility.hh"
 #include "cpu/thread_context.hh"
 
+#if FULL_SYSTEM
+#include "arch/arm/vtophys.hh"
+#include "mem/vport.hh"
+#endif
 
 namespace ArmISA {
 
@@ -57,17 +61,43 @@ initCPU(ThreadContext *tc, int cpuId)
         reset->invoke(tc);
 }
 
-uint64_t getArgument(ThreadContext *tc, int number, bool fp) {
+uint64_t getArgument(ThreadContext *tc, int &number, uint8_t size, bool fp) {
 #if FULL_SYSTEM
+    if (fp)
+        panic("getArgument(): Floating point arguments not implemented\n");
+
     if (number < NumArgumentRegs) {
-        if (fp)
-            panic("getArgument(): Floating point arguments not implemented\n");
-        else
-            return tc->readIntReg(number);
-    }
-    else {
-        panic("getArgument(): Argument index %d beyond max supported (%d).\n",
-              number, NumArgumentRegs - 1);
+        // If the argument is 64 bits, it must be in an even regiser number
+        // Increment the number here if it isn't even
+        if (size == sizeof(uint64_t)) {
+            if ((number % 2) != 0)
+                number++;
+            // Read the two halves of the data
+            // number is inc here to get the second half of the 64 bit reg
+            uint64_t tmp;
+            tmp = tc->readIntReg(number++);
+            tmp |= tc->readIntReg(number) << 32;
+            return tmp;
+        } else {
+           return tc->readIntReg(number);
+        }
+    } else {
+        Addr sp = tc->readIntReg(StackPointerReg);
+        VirtualPort *vp = tc->getVirtPort();
+        uint64_t arg;
+        if (size == sizeof(uint64_t)) {
+            // If the argument is even it must be aligned
+            if ((number % 2) != 0)
+                number++;
+            arg = vp->read<uint64_t>(sp +
+                    (number-NumArgumentRegs) * sizeof(uint32_t));
+            // since two 32 bit args == 1 64 bit arg, increment number
+            number++;
+        } else {
+            arg = vp->read<uint32_t>(sp +
+                           (number-NumArgumentRegs) * sizeof(uint32_t));
+        }
+        return arg;
     }
 #else
     panic("getArgument() only implemented for FULL_SYSTEM\n");
@@ -90,5 +120,17 @@ readCp15Register(uint32_t &Rd, int CRn, int opc1, int CRm, int opc2)
 
 }
 
+void
+skipFunction(ThreadContext *tc)
+{
+    Addr newpc = tc->readIntReg(ReturnAddressReg);
+    newpc &= ~ULL(1);
+    if (isThumb(tc->readPC()))
+        tc->setPC(newpc | PcTBit);
+    else
+        tc->setPC(newpc);
+    tc->setNextPC(tc->readPC() + sizeof(TheISA::MachInst));
+}
+
 
 }

src/arch/arm/utility.hh

@@ -156,11 +156,13 @@ namespace ArmISA {
         return !cpacr.asedis && vfpEnabled(cpacr, cpsr, fpexc);
     }
 
-uint64_t getArgument(ThreadContext *tc, int number, bool fp);
+uint64_t getArgument(ThreadContext *tc, int &number, uint8_t size, bool fp);
     
 Fault setCp15Register(uint32_t &Rd, int CRn, int opc1, int CRm, int opc2);
 Fault readCp15Register(uint32_t &Rd, int CRn, int opc1, int CRm, int opc2);
 
+void skipFunction(ThreadContext *tc);
+
 };
 
 

src/arch/mips/utility.cc

@@ -52,7 +52,7 @@ using namespace std;
 namespace MipsISA {
 
 uint64_t
-getArgument(ThreadContext *tc, int number, bool fp)
+getArgument(ThreadContext *tc, int &number, uint8_t size, bool fp)
 {
 #if FULL_SYSTEM
     if (number < 4) {
@@ -264,5 +264,14 @@ copyMiscRegs(ThreadContext *src, ThreadContext *dest)
 {
     panic("Copy Misc. Regs Not Implemented Yet\n");
 }
+void
+skipFunction(ThreadContext *tc)
+{
+    Addr newpc = tc->readIntReg(ReturnAddressReg);
+    tc->setPC(newpc);
+    tc->setNextPC(tc->readPC() + sizeof(TheISA::MachInst));
+    tc->setNextPC(tc->readNextPC() + sizeof(TheISA::MachInst));
+}
+
 
 } // namespace MipsISA

src/arch/mips/utility.hh

@@ -45,7 +45,7 @@ class ThreadContext;
 
 namespace MipsISA {
 
-uint64_t getArgument(ThreadContext *tc, int number, bool fp);
+uint64_t getArgument(ThreadContext *tc, int &number, uint8_t size, bool fp);
 
 ////////////////////////////////////////////////////////////////////////
 //
@@ -103,6 +103,8 @@ void startupCPU(ThreadContext *tc, int cpuId);
 void copyRegs(ThreadContext *src, ThreadContext *dest);
 void copyMiscRegs(ThreadContext *src, ThreadContext *dest);
 
+void skipFunction(ThreadContext *tc);
+
 };
 
 

src/arch/power/utility.cc

@@ -55,4 +55,11 @@ copyRegs(ThreadContext *src, ThreadContext *dest)
     dest->setNextPC(src->readNextPC());
 }
 
+void
+skipFunction(ThreadContext *tc)
+{
+    panic("Not Implemented for POWER");
+}
+
+
 } // PowerISA namespace

src/arch/power/utility.hh

@@ -61,6 +61,8 @@ copyMiscRegs(ThreadContext *src, ThreadContext *dest)
 {
 }
 
+void skipFunction(ThreadContext *tc);
+
 } // PowerISA namespace
 
 #endif // __ARCH_POWER_UTILITY_HH__

src/arch/sparc/utility.cc

@@ -45,7 +45,7 @@ namespace SparcISA {
 //the sixth are passed on the stack past the 16 word window save area,
 //space for the struct/union return pointer, and space reserved for the
 //first 6 arguments which the caller may use but doesn't have to.
-uint64_t getArgument(ThreadContext *tc, int number, bool fp) {
+uint64_t getArgument(ThreadContext *tc, int &number, uint8_t size, bool fp) {
 #if FULL_SYSTEM
     const int NumArgumentRegs = 6;
     if (number < NumArgumentRegs) {
@@ -218,6 +218,16 @@ copyRegs(ThreadContext *src, ThreadContext *dest)
     dest->setNextNPC(src->readNextNPC());
 }
 
+void
+skipFunction(ThreadContext *tc)
+{
+    Addr newpc = tc->readIntReg(ReturnAddressReg);
+    tc->setPC(newpc);
+    tc->setNextPC(tc->readPC() + sizeof(TheISA::MachInst));
+    tc->setNextPC(tc->readNextPC() + sizeof(TheISA::MachInst));
+}
+
+
 void
 initCPU(ThreadContext *tc, int cpuId)
 {

src/arch/sparc/utility.hh

@@ -41,7 +41,7 @@
 
 namespace SparcISA
 {
-    uint64_t getArgument(ThreadContext *tc, int number, bool fp);
+    uint64_t getArgument(ThreadContext *tc, int &number, uint8_t size, bool fp);
 
     static inline bool
     inUserMode(ThreadContext *tc)
@@ -75,6 +75,8 @@ namespace SparcISA
 
     void copyMiscRegs(ThreadContext *src, ThreadContext *dest);
 
+    void skipFunction(ThreadContext *tc);
+
 } // namespace SparcISA
 
 #endif

src/arch/x86/utility.cc

@@ -52,7 +52,7 @@
 
 namespace X86ISA {
 
-uint64_t getArgument(ThreadContext *tc, int number, bool fp) {
+uint64_t getArgument(ThreadContext *tc, int &number, uint8_t size, bool fp) {
 #if FULL_SYSTEM
     panic("getArgument() not implemented for x86!\n");
 #else
@@ -233,4 +233,11 @@ copyRegs(ThreadContext *src, ThreadContext *dest)
     dest->setNextPC(src->readNextPC());
 }
 
+void
+skipFunction(ThreadContext *tc)
+{
+    panic("Not implemented for x86\n");
+}
+
+
 } //namespace X86_ISA

src/arch/x86/utility.hh

@@ -52,7 +52,7 @@ class ThreadContext;
 
 namespace X86ISA
 {
-    uint64_t getArgument(ThreadContext *tc, int number, bool fp);
+    uint64_t getArgument(ThreadContext *tc, int &number, uint8_t size, bool fp);
 
     static inline bool
     inUserMode(ThreadContext *tc)
@@ -83,6 +83,8 @@ namespace X86ISA
     void copyRegs(ThreadContext *src, ThreadContext *dest);
 
     void copyMiscRegs(ThreadContext *src, ThreadContext *dest);
+
+    void skipFunction(ThreadContext *tc);
 };
 
 #endif // __ARCH_X86_UTILITY_HH__

src/kern/system_events.cc

@@ -30,6 +30,7 @@
  */
 
 #include "arch/isa_traits.hh"
+#include "arch/utility.hh"
 #include "base/trace.hh"
 #include "config/the_isa.hh"
 #include "cpu/thread_context.hh"
@@ -40,14 +41,9 @@ using namespace TheISA;
 void
 SkipFuncEvent::process(ThreadContext *tc)
 {
-    Addr newpc = tc->readIntReg(ReturnAddressReg);
-
     DPRINTF(PCEvent, "skipping %s: pc=%x, newpc=%x\n", description,
-            tc->readPC(), newpc);
+            tc->readPC(), tc->readIntReg(ReturnAddressReg));
 
-    tc->setPC(newpc);
-    tc->setNextPC(tc->readPC() + sizeof(TheISA::MachInst));
-#if ISA_HAS_DELAY_SLOT
-    tc->setNextPC(tc->readNextPC() + sizeof(TheISA::MachInst));
-#endif
+    // Call ISA specific code to do the skipping
+    TheISA::skipFunction(tc);
 }

src/sim/arguments.cc

@@ -50,8 +50,8 @@ Arguments::Data::alloc(size_t size)
 }
 
 uint64_t
-Arguments::getArg(bool fp)
+Arguments::getArg(uint8_t size, bool fp)
 {
-    return TheISA::getArgument(tc, number, fp);
+    return TheISA::getArgument(tc, number, size, fp);
 }
 

src/sim/arguments.hh

@@ -45,7 +45,7 @@ class Arguments
   protected:
     ThreadContext *tc;
     int number;
-    uint64_t getArg(bool fp = false);
+    uint64_t getArg(uint8_t size, bool fp = false);
 
   protected:
     class Data : public RefCounted
@@ -82,7 +82,7 @@ class Arguments
 
     // for checking if an argument is NULL
     bool operator!() {
-        return getArg() == 0;
+        return getArg(TheISA::MachineBytes) == 0;
     }
 
     Arguments &operator++() {
@@ -130,20 +130,20 @@ class Arguments
     template <class T>
     operator T() {
         assert(sizeof(T) <= sizeof(uint64_t));
-        T data = static_cast<T>(getArg());
+        T data = static_cast<T>(getArg(sizeof(T)));
         return data;
     }
 
     template <class T>
     operator T *() {
         T *buf = (T *)data->alloc(sizeof(T));
-        CopyData(tc, buf, getArg(), sizeof(T));
+        CopyData(tc, buf, getArg(sizeof(T)), sizeof(T));
         return buf;
     }
 
     operator char *() {
         char *buf = data->alloc(2048);
-        CopyStringOut(tc, buf, getArg(), 2048);
+        CopyStringOut(tc, buf, getArg(TheISA::MachineBytes), 2048);
         return buf;
     }
 };