Skip to content

Commit

Permalink
Add documentation to code, clean up code
Browse files Browse the repository at this point in the history
  • Loading branch information
@xTechon
xTechon committed Nov 29, 2021
1 parent 18198c2 commit 0b0a7ec
Show file tree
Hide file tree
Showing 2 changed files with 99 additions and 72 deletions.
171 changes: 99 additions & 72 deletions SIC Simulator/Form1.cs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -494,6 +494,11 @@ private void tsmOpen_SIC_Object_File_Click(object sender, EventArgs e)
}
}

/*
* Loads in SIC assembly code from a file
* Passes the code through an assembler
* Prompts the User for loading preference (absolute or relocating)
*/
private void tsmloadAndAssembleSICSourceFIle_Click(object sender, EventArgs e)
{
if (loadSICSourceFD.ShowDialog() == DialogResult.OK)
Expand All @@ -509,7 +514,9 @@ private void tsmloadAndAssembleSICSourceFIle_Click(object sender, EventArgs e)
this.txtObjectCode.Text = assembler.ObjectCode;
this.txtModRecs.Text = assembler.ModRecords;

//Contains only the H, T, E records
String[] lines = assembler.ObjectCode.Split('\n');
//Contains only the modification records
String[] mods = assembler.ModRecords.Split('\n');
dlgRelocatePrompt relPrompt = new dlgRelocatePrompt();
if(relPrompt.ShowDialog() == DialogResult.Yes)
Expand All @@ -521,70 +528,88 @@ private void tsmloadAndAssembleSICSourceFIle_Click(object sender, EventArgs e)
{
startad = relocate.RelocatedToAddress;
RelocateLoadObjectFile(startad,lines,mods);
//Temporary demo purposes
//LoadObjectFile(lines);

//NoteHere.ShowDialog();
}
else //If they cancel or ignore this dialogue box, they default to absolute loader
{
LoadObjectFile(lines);

}



}
else
{
//Call the Absolute Loader
DebugSuccessDisplay NoteHere = new DebugSuccessDisplay();
LoadObjectFile(lines);

LoadObjectFile(lines);
}

}
this.RefreshCPUDisplays(); // refresh memory after object code is loaded


this.LastLoadedFileName = System.IO.Path.GetFileName(loadSICSourceFD.FileName);

}
}
}//END tsmloadAndAssembleSICSourceFIle_Click()

/*
* Handles the portion of the T-record that doesn't corresspond to memory
* Works on everything in the T-record up to length
* Changes the inital address of the Trecord, and adjusts the memory address
* Declarations:
* int lineNum = Which line of the object is being modified
* ref String[] lines = String Array containing H,T,E records only
* int offset = Difference between new and old address (can be negative)
* ref int address = Position in Memory corressponding to position in T-record
* Returns:
* the new position in the Trecord
*/
private int TRecordOverhead(int lineNum, ref String[] lines, int offset, ref int address){
Debug.WriteLine(lines[lineNum]);
int pos = Int32.Parse(lines[lineNum].Substring(3,4), System.Globalization.NumberStyles.HexNumber);
address=pos; //Update the contents of address to reflect where we are in memory
Debug.WriteLine("We believe we are modifying the position "+ address.ToString("X4"));
pos +=offset;
Debug.WriteLine("We believe we are adding {0}(decimal) {1}(hex) to reach {2} ",offset,offset.ToString("X"), pos.ToString("X"));
String replacement = pos.ToString("X4");//Encode as a Hex String
//Debug.WriteLine(lines[lineNum]);
int pos = Int32.Parse(lines[lineNum].Substring(3,4), System.Globalization.NumberStyles.HexNumber);
address=pos; //Update the contents of address to reflect where we are in memory
//Debug.WriteLine("We believe we are modifying the position "+ address.ToString("X4"));
pos +=offset;
//Debug.WriteLine("We believe we are adding {0}(decimal) {1}(hex) to reach {2} ",offset,offset.ToString("X"), pos.ToString("X"));

String replacement = pos.ToString("X4"); //Encode as a Hex String
lines[lineNum] = lines[lineNum].Substring(0, 3) + replacement + lines[lineNum].Substring(7); //Remove(3,4).Insert(3,replacement);

Debug.WriteLine(lines[lineNum]);
//Debug.WriteLine(lines[lineNum]);
return 9;
//string s = "ABCDEFGH";
//s = s.Remove(3, 2).Insert(3, "ZX");
//output += String.Format("{0} {1} {2}\nLine {3}: UNDEFINED SYMBOL {4}", row.Symbol, row.OpCode, row.Operand, row.LineNumber, row.Operand);
}
private Boolean adjustString(ref String[] lines,ref int lineNum, ref int linePos, ref int Address, int TargetAddress, int offset){
}//END TRecordOverhead()

/*
* Finds the address stored in the target address and adjusts it by the offset
* works with the part of the T-record that corresponds to memory
* Declarations:
* ref String[] lines = String Array containing H,T,E records only
* ref int lineNum = Which line of the object is being modified
* ref int linePos = index of the character of the T-record string currently being checked
* ref int Address = Position in Memory corressponding to position in T-record
* int TargetAddress = Address to be modified given from M-record
* int offset = Difference between new and old address (can be negative)
* returns:
* true if an adjustment was made
* false if an adjustment cannot be made
*/
private Boolean adjustString(ref String[] lines, ref int lineNum, ref int linePos, ref int Address, int TargetAddress, int offset){
//Move through string until you hit target address. If you hit end of string go to next.
//If you hit the address make modification and return true.
//If you hit end of lines, return false.

//loop through string until target address is hit
while(lineNum<lines.Length-1){//While there are still lines.
if(Address == TargetAddress && linePos <= lines[lineNum].Length - 4)
{
//old address to be updated
int oldpos = Int32.Parse(lines[lineNum].Substring(linePos,4), System.Globalization.NumberStyles.HexNumber);
//calculate the new address
oldpos += offset;
String replacement = oldpos.ToString("X4");//Encode as a Hex String
//lines[lineNum] = lines[lineNum].Remove(linePos,4).Insert(linePos,replacement);
String replacement = oldpos.ToString("X4"); //Encode as a Hex String

//Debug.WriteLine("First: " + lines[lineNum].Substring(0, linePos) + " Second: " + replacement + " Third: " + lines[lineNum].Substring(linePos + 4));
//Debug.WriteLine("PreAdjust : " + lines[lineNum]);

Debug.WriteLine("First: " + lines[lineNum].Substring(0, linePos) + " Second: " + replacement + " Third: " + lines[lineNum].Substring(linePos + 4));
Debug.WriteLine("PreAdjust : " + lines[lineNum]);
//update the T-record
lines[lineNum] = lines[lineNum].Substring(0, linePos) + replacement + lines[lineNum].Substring(linePos + 4);
Debug.WriteLine("Post Adjust: "+lines[lineNum]);
//Debug.WriteLine("Post Adjust: "+lines[lineNum]);

//Move 4 character which is 2 bytes
//Move 4 characters which is 2 bytes
linePos +=4;
Address+=2;
return true;
Expand All @@ -593,79 +618,81 @@ private Boolean adjustString(ref String[] lines,ref int lineNum, ref int linePos
//Move 2 characters which is 1 byte
linePos+=2;
Address+=1;

if(linePos>=lines[lineNum].Length){
lineNum++;

linePos = TRecordOverhead(lineNum, ref lines,offset, ref Address);

}
}
}
return false;

}
public void RelocateLoadObjectFile(int startAdd, String[] unmodified, String[] Mrec)
}//END adjustString()

/*
* Before calling this method, proccess object code elsewhere
* This methodfies modifies the object code given in "unmodified" using M-records contained in "Mrec"
* Make sure newline characters are not passed in with the string arrays
* This only works for the SIC, not SICXE
* Declarations:
* int newAddress = the new address we want to move our program to
* String[] unmodified = Original object code given, it has been modified previously to exclude M-records (includes H, T, E records)
* String[] Mrec = string array containing only the M-records
*/
public void RelocateLoadObjectFile(int newAddress, String[] unmodified, String[] Mrec)
{
// collection of the entire obj code and M-recs
// 2 different ararys of strings
// 1 will be lines 1 will be mods
// adjust the title record to new starting address
// for each mod record, find the T record and adjust it
// loop through M-recs, loop through T records
// the M-record can occur somewhere within a T record
// keep a location counter for the T record, and every character read increments it
// reset the location counter at the start of each T record
// Output:
// Modified obj code as String array
// this is a test from Daniel

int lineNum =0; //each T record 0 is Header and last is E Record
int linePos =0; // our position in the current T record
int lineNum =0; //each T record 0 is Header and last is E Record
int linePos =0; // our position in the current T record
int curMemoryAddress=0; //current memory address corressponding to our current position in the string
int oldAddress = Int32.Parse(unmodified[lineNum].Substring(9,4), System.Globalization.NumberStyles.HexNumber); //the original starting address for each T record
int offset = startAdd-oldAddress;
Debug.WriteLine("We are moving from {0} to {1} which is a jump of {2}(dec) {3}(hex)", oldAddress.ToString("X4"), startAdd.ToString("X4"), offset, offset.ToString("X4"));

//the original starting address of the object code
int oldAddress = Int32.Parse(unmodified[lineNum].Substring(9,4), System.Globalization.NumberStyles.HexNumber);
int offset = newAddress-oldAddress;

//Debug.WriteLine("We are moving from {0} to {1} which is a jump of {2}(dec) {3}(hex)", oldAddress.ToString("X4"), newAddress.ToString("X4"), offset, offset.ToString("X4"));
String[] lines = new string[unmodified.Length]; //copy of Records
//unmodified.CopyTo(lines, 0); //Copy the unmodified records into the ones we modify
unmodified.CopyTo((String[])lines, 0);

unmodified.CopyTo((String[])lines, 0); //Copy the unmodified records into the ones we modify

//Modify H-Record
//lines[lineNum] = lines[lineNum].Remove(9,4).Insert(9,startAdd.ToString("X"));
lines[lineNum] = lines[lineNum].Substring(0, 9) + startAdd.ToString("X4") + lines[lineNum].Substring(13);
lines[lineNum] = lines[lineNum].Substring(0, 9) + newAddress.ToString("X4") + lines[lineNum].Substring(13);

//Modify E-Record
//Grabs End record, specifically address of first executable instruction and then adjusts that instruction
int firstInstruction = Int32.Parse(lines[unmodified.Length - 1].Substring(3, 4), System.Globalization.NumberStyles.HexNumber);
firstInstruction +=offset;
Debug.WriteLine("New first executable instruction: " + firstInstruction.ToString("X4"));
lines[lines.Length - 1] = "E00"+firstInstruction.ToString("X4")+"\n";
Debug.WriteLine("New E record : " + lines[unmodified.Length - 1]);
//Debug.WriteLine("New first executable instruction: " + firstInstruction.ToString("X4"));
lines[lines.Length - 1] = "E00"+firstInstruction.ToString("X4")+"\n"; //update the new E-record
//Debug.WriteLine("New E record : " + lines[unmodified.Length - 1]);

//Modify T-Records
lineNum++;
lineNum++;
// isolate part of the T-records that correspond to memory
linePos = TRecordOverhead(lineNum, ref lines,offset, ref curMemoryAddress);



//loop through the M-records
foreach(string rec in Mrec)
{
if(String.IsNullOrWhiteSpace(rec))
{
continue;
}
//T001000
//M00100104+COPY
//getting the address that needs to be modified from the Mod records
String addressSubstring = rec.Substring(3, 4);
//converting to int and subtracting 1 to match the starting address in the corresponding T record
int intAddress = Int32.Parse(addressSubstring, System.Globalization.NumberStyles.HexNumber);
//converting to int to match the starting address in the corresponding T record
int targetAddress = Int32.Parse(addressSubstring, System.Globalization.NumberStyles.HexNumber);

//String address = intAddress.ToString("X");
//Debug.WriteLine(address);
adjustString(ref lines, ref lineNum,ref linePos,ref curMemoryAddress,intAddress,offset);
//Chage address if any
adjustString(ref lines, ref lineNum,ref linePos,ref curMemoryAddress,targetAddress,offset);

}
//Make sure our lines looks like what we think it does
this.txtModdedObjectCode.Text = String.Join("\n", lines);
//Call the absolute loader on the relocated object code
LoadObjectFile(lines);
}
}//END RelocateLoadObjectFile()

private void LoadObjectFile(String[] lines) {
foreach (string line in lines)
Expand Down
Binary file modified SICVM_UnitTests/obj/Debug/DesignTimeResolveAssemblyReferencesInput.cache
View file
Binary file not shown.

1 comment on commit 0b0a7ec

@xTechon
Copy link
Collaborator Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

There are two bugs discovered after this commit,

  • Entering an invalid Hex number into the relocated start address is allowed which crashes the program
  • attempting Relocating the object code without having opened a SIC assembly file is allowed which crashes the program

Please sign in to comment.