checkpoint

1 files changed, 0 insertions, 535 deletions

diff --git a/src/sim86.cpp b/src/sim86.cpp
deleted file mode 100644
index 7c444bd..0000000
--- a/src/sim86.cpp
+++ /dev/null
@@ -1,535 +0,0 @@
-#include <stdio.h>
-#include <string.h>
-
-#include "./libs/reference_decoder/sim86_lib.cpp"
-
-#include "sim86.h"
-#include "clocks_table.inl"
-#include "generated/generated.cpp"
-
-global_variable u8 GlobalMemory[1*1024*1024] = {};
-
-internal void
-SetOrUnsetFlag(u32 *FlagsRegister, b32 Condition, flags_8086 Flag)
-{
-    if(Condition)
-    {
-        *FlagsRegister |= Flag;
-    }
-    else
-    {
-        *FlagsRegister &= (~Flag);
-    }
-}
-
-internal u32
-FlagsToString(char *Buffer, u32 Flags)
-{
-    u32 Length = 0;
-    
-    for(s32 MappingIndex = 0;
-        MappingIndex < flags_8086_strings_count;
-        MappingIndex++)
-    {
-        u8 Char = flags_8086_strings[MappingIndex][0];
-        b32 IsBitSet = (Flags & 1);
-        Flags >>= 1;
-        if(IsBitSet)
-        {
-            Buffer[Length++] = Char;
-        }
-    }
-    
-    return Length;
-}
-
-// Sets flags by checking the destination value of the register.
-internal void
-FlagsFromValue(u32 *FlagsRegister, u32 InstructionFlags, s32 Value)
-{
-    u32 OldFlagsRegister = *FlagsRegister;
-    
-    u32 SignMask = (1 << ((InstructionFlags & Inst_Wide) ? 15 : 7));
-    SetOrUnsetFlag(FlagsRegister, (Value & SignMask), Flag_Sign);
-    SetOrUnsetFlag(FlagsRegister, (Value == 0),       Flag_Zero);
-    
-    // NOTE(luca): Parity flag is set when in lower 8 bits have an even number of set bits.
-    u32 OneBitsCount = 0;
-    for(u32 BitsIndex = 0;
-        BitsIndex < 8;
-        BitsIndex++)
-    {
-        OneBitsCount += (Value & 1);
-        Value >>= 1;
-    }
-    SetOrUnsetFlag(FlagsRegister, (!(OneBitsCount & 1)), Flag_Parity);
-    
-    // TODO(luca): Overflow flag
-    // Were we adding positive numbers but produced a negative number?
-    
-    // TODO(luca): Carry flag 
-    // When twot numbers are added and the 17th bit would be set?
-    
-    // TODO(luca): Auxiliary carry flag
-    // Carry for bottom 8 bits
-    if(*FlagsRegister != OldFlagsRegister)
-    {
-        char OldFlagsString[ArrayCount(flags_8086_strings)] = {};
-        char FlagsString[ArrayCount(flags_8086_strings)] = {};
-        FlagsToString(OldFlagsString, OldFlagsRegister);
-        FlagsToString(FlagsString, *FlagsRegister);
-        
-        printf(" flags:%s->%s", OldFlagsString, FlagsString);
-    }
-}
-
-s32 GetCompleteDisplacement(s32 *Registers, instruction_operand *Operand)
-{
-    s32 CompleteDisplacement = Operand->Address.Displacement;
-    
-    u32 Count = Operand->Address.Terms[0].Register.Count;
-    u32 Mask = ((u32)((-1)) >> (16 + (16 - Count*8)));
-    CompleteDisplacement += 
-    (Registers[Operand->Address.Terms[0].Register.Index] & Mask) +
-    (Registers[Operand->Address.Terms[1].Register.Index] & Mask);
-    
-    return CompleteDisplacement;
-}
-
-internal s32 *
-OperandToValue(s32 *Registers, u8 *Memory, instruction_operand *Operand)
-{
-    s32 *Result = 0;
-    
-    if(0) {}
-    else if(Operand->Type == Operand_Register)
-    {
-        Result = Registers + Operand->Register.Index;
-    }
-    else if(Operand->Type == Operand_Memory)
-    {
-        s32 CompleteDisplacement = GetCompleteDisplacement(Registers, Operand);
-        Result = (s32 *)((u8 *)Memory + CompleteDisplacement);
-    }
-    else if(Operand->Type == Operand_Immediate)
-    {
-        Result = &Operand->Immediate.Value;
-    }
-    else if(Operand->Type != Operand_None)
-    {
-        Assert(0);
-    }
-    
-    return Result;
-}
-
-b32 IsAccumulator(instruction_operand *Operand)
-{
-    b32 Result = ((Operand->Type == Operand_Register) &&
-                  (Operand->Register.Index == Register_a));
-    return Result;
-}
-
-b32 IsMatchingOp(instruction_operand *Operand, instruction_clocks_operand_type Type)
-{
-    b32 Matching = false;
-    
-    Matching = Matching || (Type == InstructionClocksOperand_Memory && Operand->Type == Operand_Memory);
-    Matching = Matching || (Type == InstructionClocksOperand_Register && Operand->Type == Operand_Register);
-    Matching = Matching || (Type == InstructionClocksOperand_Accumulator && IsAccumulator(Operand));
-    Matching = Matching || (Type == InstructionClocksOperand_Immediate && Operand->Type == Operand_Immediate);
-    
-    return Matching;
-}
-
-internal void
-Run8086(psize MemorySize, u8 *Memory)
-{
-    s32 Registers[Register_count] = {}; 
-    u32 FlagsRegister = 0;
-    u32 IPRegister = 0;
-    u32 ElapsedClocks = 0;
-    
-    while(IPRegister < MemorySize)
-    {
-        instruction Decoded;
-        Sim86_Decode8086Instruction(MemorySize - IPRegister, Memory + IPRegister, &Decoded);
-        if(Decoded.Op)
-        {
-            u32 OldIPRegister = IPRegister;
-            
-#if SIM86_INTERNAL           
-            printf("%s ;", Sim86_MnemonicFromOperationType(Decoded.Op));
-#endif
-            
-            instruction_operand *DestinationOperand = Decoded.Operands + 0;
-            instruction_operand *SourceOperand      = Decoded.Operands + 1;
-            
-            u32 AddedClocks = 0;
-            for(u32 ClocksIndex = 0;
-                ClocksIndex < ArrayCount(ClocksTable);
-                ClocksIndex++)
-            {
-                instruction_clocks *Clocks = ClocksTable + ClocksIndex;
-                
-                b32 Matching = Decoded.Op == Clocks->Op; 
-                Matching = Matching && IsMatchingOp(DestinationOperand, Clocks->Operands[0]);
-                Matching = Matching && IsMatchingOp(SourceOperand, Clocks->Operands[1]);
-                if(Matching)
-                {
-                    AddedClocks += Clocks->Clocks;
-                    
-                    if(Clocks->EffectiveAddress)
-                    {
-                        instruction_operand *MemoryOperand = ((DestinationOperand->Type == Operand_Memory) ? DestinationOperand : SourceOperand);
-                        u32 FirstIndex = MemoryOperand->Address.Terms[0].Register.Index;
-                        u32 SecondIndex = MemoryOperand->Address.Terms[1].Register.Index;
-                        
-                        // Only displacement
-                        if(FirstIndex == 0 && SecondIndex == 0)
-                        {
-                            AddedClocks += 6;
-                        }
-                        // Base or index
-                        else if(FirstIndex == 0 || SecondIndex == 0)
-                        {
-                            // Base or index only
-                            if(MemoryOperand->Address.Displacement == 0)
-                            {
-                                AddedClocks += 5;
-                            }
-                            // Base or index + displacement
-                            else
-                            {
-                                AddedClocks += 9;
-                            }
-                        }
-                        // Base + index
-                        else if(MemoryOperand->Address.Displacement == 0)
-                        {
-                            /*
-                            bp+di bx+si 7
-                                bp+si bx+di 8
-                                */
-                            if((FirstIndex == Register_bp && SecondIndex == Register_di) ||
-                               (FirstIndex == Register_b && SecondIndex == Register_si))
-                            {
-                                AddedClocks += 7;
-                            }
-                            else
-                            {
-                                AddedClocks += 8;
-                            }
-                        }
-                        // Base + index + displacement
-                        else
-                        {
-                            /*
-                            bp+di bx+si 11
-                                bp+si bx+di 12
-                                */
-                            if((FirstIndex == Register_bp && SecondIndex == Register_di) ||
-                               (FirstIndex == Register_b && SecondIndex == Register_si))
-                            {
-                                AddedClocks += 11;
-                            }
-                            else
-                            {
-                                AddedClocks += 12;
-                            }
-                        }
-                        
-                    }
-                    
-                    // Add transfer penalty
-                    if(Clocks->Transfers && (Decoded.Flags & Inst_Wide))
-                    {
-                        instruction_operand *MemoryOperand = ((DestinationOperand->Type == Operand_Memory) ? DestinationOperand : SourceOperand);
-                        s32 Displacement = GetCompleteDisplacement(Registers, MemoryOperand);
-                        if(Displacement & 1)
-                        {
-                            AddedClocks += 4*Clocks->Transfers;
-                        }
-                    }
-                    
-                    break;
-                }
-            }
-            
-#if 0            
-            Assert(AddedClocks);
-#endif
-            
-            ElapsedClocks += AddedClocks;
-            printf(" clocks: +%d = %d", AddedClocks, ElapsedClocks);
-            
-            s32 *Destination = OperandToValue(Registers, Memory, DestinationOperand);
-            s32 *Source      = OperandToValue(Registers, Memory, SourceOperand);
-            
-            if(0) {}
-            else if(Decoded.Op == Op_int3)
-            {
-                Assert(0);
-            }
-            else if(Decoded.Op == Op_mov)
-            {
-                s32 Old = *Destination;
-                if(Decoded.Flags & Inst_Wide)
-                {
-                    *(u16 *)Destination = *(u16 *)Source;
-                }
-                else
-                {
-                    Assert((SourceOperand->Type == Operand_Immediate ||
-                            SourceOperand->Type == Operand_Memory) &&
-                           (SourceOperand->Register.Offset == 0));
-                    Assert((DestinationOperand->Type == Operand_Immediate || DestinationOperand->Type == Operand_Memory) && (DestinationOperand->Register.Offset == 0));
-                    
-                    u8 *SourceByte = (u8 *)Source + SourceOperand->Register.Offset;
-                    u8 *DestByte   = (u8 *)Destination + DestinationOperand->Register.Offset;
-                    
-                    *DestByte = *SourceByte;
-                }
-                
-#if SIM86_INTERNAL                    
-                if(DestinationOperand->Type == Operand_Register)
-                {
-                    printf(" %s:0x%x->0x%x", Sim86_RegisterNameFromOperand(&DestinationOperand->Register),
-                           Old, *Destination);
-                }
-#endif
-            }
-            else if(Decoded.Op == Op_ret)
-            {
-                printf("\n");
-                printf("STOPONRET: Return encountered at address %d.\n", IPRegister);
-                
-                break;
-            }
-            else if(Decoded.Op == Op_inc)
-            {
-                Assert(DestinationOperand->Type == Operand_Register);
-                Assert(SourceOperand->Type == Operand_None);
-                *Destination += 1;
-            }
-            else if(Decoded.Op == Op_test)
-            {
-                
-                Assert(DestinationOperand->Type == Operand_Register);
-                Assert(SourceOperand->Type == Operand_Register || SourceOperand->Type == Operand_Immediate);
-                
-                s32 Value =((Decoded.Flags & Inst_Wide) ? 
-                            (u16)((u16)*Destination & ((u16)*Source)) :
-                            (u8)((u8)*Destination & ((u8)*Source))); 
-                FlagsFromValue(&FlagsRegister, Decoded.Flags, Value);
-            }
-            else if(Decoded.Op == Op_xor)
-            {
-                
-                Assert(DestinationOperand->Type == Operand_Register);
-                Assert(SourceOperand->Type == Operand_Register || SourceOperand->Type == Operand_Immediate);
-                
-                s32 Value =((Decoded.Flags & Inst_Wide) ? 
-                            (u16)((u16)*Destination ^ ((u16)*Source)) :
-                            (u8)((u8)*Destination ^ ((u8)*Source))); 
-                FlagsFromValue(&FlagsRegister, Decoded.Flags, Value);
-                *Destination = Value;
-            }
-            else if(Decoded.Op == Op_cmp)
-            {
-                Assert(DestinationOperand->Type == Operand_Register);
-                Assert(SourceOperand->Type == Operand_Register || SourceOperand->Type == Operand_Immediate);
-                
-                s32 Value = ((Decoded.Flags & Inst_Wide) ? 
-                             (u16)((u16)*Destination - ((u16)*Source)) :
-                             (u8)((u8)*Destination - ((u8)*Source)));
-                
-                FlagsFromValue(&FlagsRegister, Decoded.Flags, Value);
-            }
-            else if(Decoded.Op == Op_sub)
-            {
-                Assert(DestinationOperand->Type == Operand_Register);
-                Assert(SourceOperand->Type == Operand_Register || SourceOperand->Type == Operand_Immediate);
-                
-                s32 Old = *Destination;
-                *Destination = ((Decoded.Flags & Inst_Wide) ? 
-                                (u16)((u16)*Destination - ((u16)*Source)) :
-                                (u8)((u8)*Destination - ((u8)*Source)));
-                
-                printf(" %s:0x%x->0x%x", 
-                       Sim86_RegisterNameFromOperand(&DestinationOperand->Register),
-                       Old, *Destination);
-                
-                FlagsFromValue(&FlagsRegister, Decoded.Flags, *Destination);
-                
-            }
-            else if(Decoded.Op == Op_add)
-            {
-                s32 Old = *Destination;
-                
-                *Destination = ((Decoded.Flags & Inst_Wide) ? 
-                                (u16)((u16)*Destination + ((u16)*Source)) :
-                                (u8)((u8)*Destination + ((u8)*Source)));
-                
-                printf(" %s:0x%x->0x%x", 
-                       Sim86_RegisterNameFromOperand(&DestinationOperand->Register),
-                       Old, *Destination);
-                
-                FlagsFromValue(&FlagsRegister, Decoded.Flags, *Destination);
-            }
-            else if(Decoded.Op == Op_jne)
-            {
-                if(!(FlagsRegister & Flag_Zero))
-                {
-                    IPRegister += *Destination;
-                }
-            }
-            else if(Decoded.Op == Op_je)
-            {
-                if((FlagsRegister & Flag_Zero))
-                {
-                    IPRegister += *Destination;
-                }
-            }
-            else
-            {
-                Assert(0 && "Op not implemented yet.");
-            }
-            
-            IPRegister += Decoded.Size;
-            
-#if SIM86_INTERNAL
-            printf(" ip:0x%x->0x%x", OldIPRegister, IPRegister);
-#endif
-            
-        }
-        else
-        {
-            printf("Unrecognized instruction\n");
-            break;
-        }
-        
-#if SIM86_INTERNAL
-        printf("\n");
-#endif
-        
-    }
-    
-    printf("\nFinal registers:\n");
-    for(u32 RegisterIndex = Register_a;
-        RegisterIndex < Register_ds + 1;
-        RegisterIndex++)
-    {
-        register_access Register = {};
-        Register.Index = RegisterIndex;
-        Register.Offset = 0;
-        Register.Count = 2;
-        
-        u32 Value = Registers[RegisterIndex];
-        if(Value > 0)
-        {
-            printf("     %s: 0x%0x (%d)\n", 
-                   Sim86_RegisterNameFromOperand(&Register),
-                   Value, Value);
-        }
-    }
-    printf("     ip: 0x%04x (%d)\n", IPRegister, IPRegister);
-    
-    if(FlagsRegister)
-    {
-        char FlagsString[ArrayCount(flags_8086_strings)] = {};
-        FlagsToString(FlagsString, FlagsRegister);
-        printf("  flags: %s\n", FlagsString);
-    }
-}
-
-void PrintUsage(char *ExePath)
-{
-    printf("usage: %s [-exec] <assembly>\n", ExePath);
-}
-
-int main(int ArgsCount, char *Args[])
-{
-    u32 Version = Sim86_GetVersion();
-    
-#if SIM86_INTERNAL    
-    printf("Sim86 Version: %u (expected %u)\n", Version, SIM86_VERSION);
-#endif
-    
-    if(Version != SIM86_VERSION)
-    {
-        printf("ERROR: Header file version doesn't match DLL.\n");
-        return -1;
-    }
-    
-    instruction_table Table;
-    Sim86_Get8086InstructionTable(&Table);
-    
-#if SIM86_INTERNAL    
-    printf("8086 Instruction Instruction Encoding Count: %u\n", Table.EncodingCount);
-#endif
-    
-    // print (default)
-    // -exec (also execute the disassembled instructinos)
-    
-    b32 Execute = false;
-    b32 Dump = false;
-    char *FileName = 0;
-    for(s32 ArgsIndex = 1;
-        ArgsIndex < ArgsCount;
-        ArgsIndex++)
-    {
-        char *Command = Args[ArgsIndex];
-        if(0) {}
-        else if(!strcmp(Command, "-exec"))
-        {
-            Execute = true;
-        }
-        else if(!strcmp(Command, "-dump"))
-        {
-            Dump = true;
-        }
-        else 
-        {
-            FileName = Command;
-        }
-    }
-    
-    if(FileName)
-    {
-        FILE *File = fopen(FileName, "rb");
-        if(File)
-        {
-            psize BytesWritten = fread(GlobalMemory, 1, sizeof(GlobalMemory), File);
-            fclose(File);
-            
-            if(Execute)
-            {
-                printf("--- %s execution ---\n", FileName);
-                
-                Run8086(BytesWritten, GlobalMemory);
-                
-                if(Dump)
-                {
-                    // NOTE(luca): We have to add ".data" or Gimp will throw an error. 
-                    FILE *DumpFile = fopen("sim86_memory_0.data", "wb");
-                    fwrite(GlobalMemory, 1, sizeof(GlobalMemory), DumpFile);
-                    fclose(DumpFile);
-                }
-                
-            }
-            else
-            {
-                printf("ERROR: Disassembling not implemented yet.\n");
-            }
-            
-        }
-        else
-        {
-            printf("ERROR: Unable to open %s.\n", FileName);
-            PrintUsage(Args[0]);
-        }
-    }
-    
-    return 0;
-}