[Simulavr-devel] [PATCH 09/13] Three-level hardware stack

[Onno Kortmann]

Support for the three-level hardware stack on devices
such as the 90S1200 or the Tiny15l.

Signed-off-by: Onno Kortmann <address@hidden>
---
 src/at4433.cpp    |    2 +-
 src/at8515.cpp    |    2 +-
 src/atmega128.cpp |    2 +-
 src/hwstack.cpp   |   25 +++++++++++++------------
 src/hwstack.h     |   26 +++++++++++++++++++++++---
 5 files changed, 39 insertions(+), 18 deletions(-)

diff --git a/src/at4433.cpp b/src/at4433.cpp
index 25656d0..f1ea1fc 100644
--- a/src/at4433.cpp
+++ b/src/at4433.cpp
@@ -46,7 +46,7 @@ AvrDevice(64, 128, 0, 4*1024) {
 
        irqSystem = new HWIrqSystem(this, 2);
     eeprom= new HWMegaEeprom(this, irqSystem, 256, 12); //we use a eeprom with 
irq here
-       stack = new HWStack(this, Sram, 0x00ff);
+       stack = new HWStack(this, Sram, 0x0100);
 
        portb= new HWPort(this, "B");
        portc= new HWPort(this, "C");
diff --git a/src/at8515.cpp b/src/at8515.cpp
index b319666..d7cdb9d 100644
--- a/src/at8515.cpp
+++ b/src/at8515.cpp
@@ -37,7 +37,7 @@ AvrDevice(64, 512, 0xfda0, 8192) {
     eeprom= new HWEeprom(this, 512);
 
        irqSystem = new HWIrqSystem(this, 2);
-       stack = new HWStack(this, Sram, 0xffff);
+       stack = new HWStack(this, Sram, 0x10000);
 
        porta= new HWPort(this, "A");
        portb= new HWPort(this, "B");
diff --git a/src/atmega128.cpp b/src/atmega128.cpp
index 0ece665..075bf40 100644
--- a/src/atmega128.cpp
+++ b/src/atmega128.cpp
@@ -40,7 +40,7 @@ AvrDevice_atmega128::AvrDevice_atmega128():
 AvrDevice(224, 4096, 0xef00, 128*1024) { 
        irqSystem = new HWIrqSystem(this, 4); //4 bytes per vector
     eeprom = new HWMegaEeprom( this, irqSystem, 4096, 22); 
-       stack = new HWStack(this, Sram, 0xffff);
+       stack = new HWStack(this, Sram, 0x10000);
        porta= new HWPort(this, "A");
        portb= new HWPort(this, "B");
        portc= new HWPort(this, "C");
diff --git a/src/hwstack.cpp b/src/hwstack.cpp
index d093f1c..911549d 100644
--- a/src/hwstack.cpp
+++ b/src/hwstack.cpp
@@ -32,10 +32,10 @@ RWSph::operator unsigned char() const { return 
hwstack->GetSph();  }
 
 
 
-HWStack::HWStack(AvrDevice *c, MemoryOffsets *sr, unsigned int 
mask):Hardware(c), core(c) {
-    stackMask=mask;
-       mem=sr;
-       Reset();
+HWStack::HWStack(AvrDevice *c, MemoryOffsets *sr, unsigned int 
ceil):Hardware(c), core(c) {
+    stackCeil=ceil;
+    mem=sr;
+    Reset();
 }
 
 void HWStack::Reset() {
@@ -55,22 +55,23 @@ void HWStack::CheckBreakPoints() {
 void HWStack::Push(unsigned char val){
        (*mem)[stackPointer]=val;
        stackPointer--;
-    stackPointer&=stackMask;
-       if (core->trace_on==1) traceOut << "SP=0x" << hex << stackPointer << 
dec << " " ;
-    CheckBreakPoints();
+       if (stackPointer>0x1000000)
+           stackPointer=stackCeil-1;
+       if (core->trace_on==1) traceOut << "SP=0x" << hex << stackPointer << " 
0x" << int(val) << dec << " ";
+       CheckBreakPoints();
 }
 unsigned char HWStack::Pop(){
        stackPointer++;
-    stackPointer&=stackMask;
-       if (core->trace_on==1) traceOut << "SP=0x" << hex << stackPointer << 
dec << " " ;
-    CheckBreakPoints();
+       stackPointer%=stackCeil;
+       if (core->trace_on==1) traceOut << "SP=0x" << hex << stackPointer << " 
0x" << int((*mem)[stackPointer]) << dec << " ";
+       CheckBreakPoints();
        return (*mem)[stackPointer];
 }
 
 void HWStack::SetSpl(unsigned char val) {
        stackPointer=stackPointer&0xffff00;
        stackPointer+=val;
-    stackPointer&=stackMask;
+       stackPointer%=stackCeil;
        if (core->trace_on==1) traceOut << "SP=0x" << hex << stackPointer << 
dec << " " ; 
     CheckBreakPoints();
 }
@@ -78,7 +79,7 @@ void HWStack::SetSpl(unsigned char val) {
 void HWStack::SetSph(unsigned char val) {
        stackPointer=stackPointer&0xff00ff;
        stackPointer+=(val<<8);
-    stackPointer&=stackMask;
+       stackPointer%=stackCeil;
        if (core->trace_on==1) traceOut << "SP=0x" << hex << stackPointer << 
dec << " " ; 
     CheckBreakPoints();
 }
diff --git a/src/hwstack.h b/src/hwstack.h
index 9b9b54f..5180b52 100644
--- a/src/hwstack.h
+++ b/src/hwstack.h
@@ -31,17 +31,37 @@
 #include <map>
 
 
+/*! Implementation of the special three-level deep hardware stack which is
+  not accessible in any memory space on the devices which have this, for
+  example the ATTiny15L or the good old AT90S1200. */
+class ThreeLevelStack : public MemoryOffsets {
+ public:
+    ThreeLevelStack() : MemoryOffsets(0, 0) {
+               rwHandler=(RWMemoryMembers**)malloc(sizeof(RWMemoryMembers*) * 
6);
+               for (size_t i=0; i < 6; i++) {
+                   rwHandler[i]=new RWMemoryWithOwnMemory(0);
+               }
+    }
+    ~ThreeLevelStack() {
+       free(rwHandler);
+    }
+};
+
+
 class HWStack: public Hardware {
        protected:
         AvrDevice *core;
                MemoryOffsets *mem;
                unsigned int stackPointer;
-        unsigned int stackMask;
+        unsigned int stackCeil;
         multimap<unsigned int , Funktor* > breakPointList; //later the second 
parameter should be a function Pointer!
 
        public:
-        //the mask give the max width of the stack pointer, in smaller devices 
there are not all 16 bits available!
-               HWStack(AvrDevice *core, MemoryOffsets *sr, unsigned int mask);
+        /*!Ceil gives the maximum value (+1) for the stack pointer, in smaller 
devices
+         there are not all 16 bits available!
+         Ceil does not need to be a power of two.
+         */
+       HWStack(AvrDevice *core, MemoryOffsets *sr, unsigned int ceil);
                void Push(unsigned char val);
                unsigned char Pop();
 
-- 
1.5.6.5