[aandrejevic] 60600: [SOFT386] Implement the REP prefix for the INS instruction.

Author: aandrejevic
Date: Thu Oct 10 19:01:41 2013
New Revision: 60600

URL: http://svn.reactos.org/svn/reactos?rev=60600&view=rev
Log:
[SOFT386]
Implement the REP prefix for the INS instruction.


Modified:
    branches/ntvdm/lib/soft386/common.h
    branches/ntvdm/lib/soft386/opcodes.c

Modified: branches/ntvdm/lib/soft386/common.h
URL:
http://svn.reactos.org/svn/reactos/branches/ntvdm/lib/soft386/common.h?rev=…
==============================================================================
--- branches/ntvdm/lib/soft386/common.h	[iso-8859-1] (original)
+++ branches/ntvdm/lib/soft386/common.h	[iso-8859-1] Thu Oct 10 19:01:41 2013
@@ -33,6 +33,9 @@
 #define SIGN_FLAG_LONG  0x80000000
 #define REAL_MODE_FLAGS_MASK 0x17FD5
 #define PROT_MODE_FLAGS_MASK 0x10DD5
+
+/* Block size for string operations */
+#define STRING_BLOCK_SIZE 4096
 
 #define GET_SEGMENT_RPL(s)          ((s) & 3)
 #define GET_SEGMENT_INDEX(s)        ((s) & 0xFFF8)

Modified: branches/ntvdm/lib/soft386/opcodes.c
URL:
http://svn.reactos.org/svn/reactos/branches/ntvdm/lib/soft386/opcodes.c?rev…
==============================================================================
--- branches/ntvdm/lib/soft386/opcodes.c	[iso-8859-1] (original)
+++ branches/ntvdm/lib/soft386/opcodes.c	[iso-8859-1] Thu Oct 10 19:01:41 2013
@@ -6311,7 +6311,6 @@
 
 SOFT386_OPCODE_HANDLER(Soft386OpcodeIns)
 {
-    ULONG Data = 0;
     ULONG DataSize;
     BOOLEAN OperandSize, AddressSize;
 
@@ -6330,48 +6329,114 @@
     {
         /* The ADSIZE prefix toggles the size */
         AddressSize = !AddressSize;
-    }
-
-    if ((State->PrefixFlags & SOFT386_PREFIX_REP)
-        || (State->PrefixFlags & SOFT386_PREFIX_REPNZ))
-    {
-        // TODO: The REP/REPZ/REPNZ prefixes need to be implemented!
-        Soft386Exception(State, SOFT386_EXCEPTION_UD);
-        return FALSE;
     }
 
     /* Calculate the size */
     if (Opcode == 0x6C) DataSize = sizeof(UCHAR);
     else DataSize = OperandSize ? sizeof(ULONG) : sizeof(USHORT);
 
-    /* Read from the I/O port */
-    State->IoReadCallback(State,
-                          State->GeneralRegs[SOFT386_REG_EDX].LowWord,
-                          &Data,
-                          DataSize);
-
-    /* Write to the destination operand */
-    if (!Soft386WriteMemory(State,
-                            SOFT386_REG_ES,
-                            AddressSize ? State->GeneralRegs[SOFT386_REG_EDI].Long
-                                        :
State->GeneralRegs[SOFT386_REG_EDI].LowWord,
-                            &Data,
-                            DataSize))
-    {
-        /* Exception occurred */
-        return FALSE;
-    }
-
-    /* Increment/decrement EDI */
-    if (OperandSize)
-    {
-        if (State->Flags.Df) State->GeneralRegs[SOFT386_REG_EDI].Long += DataSize;
-        else State->GeneralRegs[SOFT386_REG_EDI].Long -= DataSize;
+    if (State->PrefixFlags & SOFT386_PREFIX_REP)
+    {
+        UCHAR Block[STRING_BLOCK_SIZE];
+        ULONG Count = OperandSize ? State->GeneralRegs[SOFT386_REG_ECX].Long
+                                  : State->GeneralRegs[SOFT386_REG_ECX].LowWord;
+
+        /* Transfer until finished */
+        while (Count)
+        {
+            ULONG Processed = min(Count, STRING_BLOCK_SIZE / DataSize);
+
+            /* Read from the I/O port */
+            State->IoReadCallback(State,
+                                  State->GeneralRegs[SOFT386_REG_EDX].LowWord,
+                                  Block,
+                                  Processed * DataSize);
+
+            if (State->Flags.Df)
+            {
+                ULONG i, j;
+
+                /* Reduce EDI by the number of bytes to transfer */
+                if (AddressSize) State->GeneralRegs[SOFT386_REG_EDI].Long -= Processed
* DataSize;
+                else State->GeneralRegs[SOFT386_REG_EDI].LowWord -= Processed *
DataSize;
+
+                /* Reverse the block data */
+                for (i = 0; i < Processed / 2; i++)
+                {
+                    /* Swap the values */
+                    for (j = 0; j < DataSize; j++)
+                    {
+                        UCHAR Temp = Block[i * DataSize + j];
+                        Block[i * DataSize + j] = Block[(Processed - i - 1) * DataSize +
j];
+                        Block[(Processed - i - 1) * DataSize + j] = Temp;
+                    }
+                }
+            }
+
+            /* Write to memory */
+            if (!Soft386WriteMemory(State,
+                                    SOFT386_REG_ES,
+                                    AddressSize ?
State->GeneralRegs[SOFT386_REG_EDI].Long
+                                                :
State->GeneralRegs[SOFT386_REG_EDI].LowWord,
+                                    Block,
+                                    Processed * DataSize))
+            {
+                /* Set ECX */
+                if (OperandSize) State->GeneralRegs[SOFT386_REG_ECX].Long = Count;
+                else State->GeneralRegs[SOFT386_REG_ECX].LowWord = LOWORD(Count);
+
+                /* Exception occurred */
+                return FALSE;
+            }
+
+            if (!State->Flags.Df)
+            {
+                /* Increase EDI by the number of bytes transfered */
+                if (AddressSize) State->GeneralRegs[SOFT386_REG_EDI].Long += Processed
* DataSize;
+                else State->GeneralRegs[SOFT386_REG_EDI].LowWord += Processed *
DataSize;
+            }
+
+            /* Reduce the total count by the number processed in this run */
+            Count -= Processed;
+        }
+
+        /* Clear ECX */
+        if (OperandSize) State->GeneralRegs[SOFT386_REG_ECX].Long = 0;
+        else State->GeneralRegs[SOFT386_REG_ECX].LowWord = 0;
     }
     else
     {
-        if (State->Flags.Df) State->GeneralRegs[SOFT386_REG_EDI].LowWord +=
DataSize;
-        else State->GeneralRegs[SOFT386_REG_EDI].LowWord -= DataSize;
+        ULONG Data = 0;
+
+        /* Read from the I/O port */
+        State->IoReadCallback(State,
+                              State->GeneralRegs[SOFT386_REG_EDX].LowWord,
+                              &Data,
+                              DataSize);
+
+        /* Write to the destination operand */
+        if (!Soft386WriteMemory(State,
+                                SOFT386_REG_ES,
+                                AddressSize ?
State->GeneralRegs[SOFT386_REG_EDI].Long
+                                            :
State->GeneralRegs[SOFT386_REG_EDI].LowWord,
+                                &Data,
+                                DataSize))
+        {
+            /* Exception occurred */
+            return FALSE;
+        }
+
+        /* Increment/decrement EDI */
+        if (OperandSize)
+        {
+            if (State->Flags.Df) State->GeneralRegs[SOFT386_REG_EDI].Long +=
DataSize;
+            else State->GeneralRegs[SOFT386_REG_EDI].Long -= DataSize;
+        }
+        else
+        {
+            if (State->Flags.Df) State->GeneralRegs[SOFT386_REG_EDI].LowWord +=
DataSize;
+            else State->GeneralRegs[SOFT386_REG_EDI].LowWord -= DataSize;
+        }
     }
 
     /* Return success */