/// <summary>
/// The monitor recieved 0x00, 'p' ...
/// Read the command ID bytes following that and process them.
/// </summary>
public static bool ReadCommand()
{
Console.WriteLine("Got PCDRV ...");
// Wait till we get the PCDrv function code
while (serial.BytesToRead == 0)
{
}
PCDrvCodes funcCode = (PCDrvCodes)TransferLogic.read32();
Console.WriteLine("Got function code: " + funcCode);
// TODO: split these off into discrete functions?
// PCInit
if (funcCode == PCDrvCodes.PCINIT_101)
{
serial.Write("OKAY");
serial.Write(new byte[] { 0 }, 0, 1);
return(true);
}
// PCCreat
if (funcCode == PCDrvCodes.PCCREAT_102)
{
// tell unirom to start with the filename, etc
serial.Write("OKAY");
string fileName = GetFilename();
if (fileName == "")
{
return(false);
}
UInt32 parameters = TransferLogic.read32();
bool isDir = ((parameters & 16) != 0);
Console.WriteLine($"PCCreat( {fileName}, {parameters} )");
PCFile pcFile = GetOpenFile(fileName);
if (pcFile != null)
{
// We're already tracking this file, just return it's handle
Console.WriteLine("File already open, handle=" + pcFile.handle);
serial.Write("OKAY");
serial.Write(BitConverter.GetBytes(pcFile.handle), 0, 4);
return(true);
}
FileStream fStream;
try {
if (isDir)
{
throw new Exception("Directories are not supported!");
}
else
{
if (!File.Exists(fileName))
{
FileStream tempStream = File.Create(fileName);
tempStream.Flush();
tempStream.Close();
tempStream.Dispose();
}
else
{
Console.WriteLine($"File {fileName} already exists, using that...");
}
fStream = new FileStream(fileName, FileMode.Open, FileAccess.ReadWrite, FileShare.ReadWrite);
}
// open it read/write until otherwise specified via PCOpen
UInt32 handle = NextHandle();
TrackFile(fileName, handle, fStream, PCFileMode.READWRITE);
serial.Write("OKAY");
serial.Write(BitConverter.GetBytes(handle), 0, 4);
return(true);
} catch (Exception e) {
Console.WriteLine($"Error creating file '{fileName}', ex={e}");
serial.Write("NOPE");
return(false);
}
} // PCCREAT_102
// PCOpen
if (funcCode == PCDrvCodes.PCOPEN_103)
{
serial.Write("OKAY");
string fileName = GetFilename();
if (fileName == "")
{
return(false);
}
PCFileMode fileModeParams = (PCFileMode)TransferLogic.read32();
Console.WriteLine($"PCOpen( {fileName}, {fileModeParams} )");
PCFile f = GetOpenFile(fileName);
if (f != null)
{
// just return the handle for this file...
if (f.fileMode != fileModeParams)
{
Console.WriteLine($"File {f.handle} already open, switching params to {fileModeParams}");
f.fileMode = fileModeParams;
}
else
{
Console.WriteLine("File already open, handle=" + f.handle);
}
serial.Write("OKAY");
serial.Write(BitConverter.GetBytes(f.handle), 0, 4);
return(true);
}
if (!File.Exists(fileName))
{
Console.WriteLine("File doesn't exist!");
goto nope;
}
FileStream fs = null;
try{
fs = File.Open(fileName, FileMode.Open, FileAccess.ReadWrite, FileShare.ReadWrite);
} catch (Exception e) {
Console.WriteLine($"Error opening file '{fileName}', ex={e}");
goto nope;
}
UInt32 handle = NextHandle();
TrackFile(fileName, handle, fs, fileModeParams);
Console.WriteLine("Returning file, handle=" + handle);
serial.Write("OKAY");
serial.Write(BitConverter.GetBytes(handle), 0, 4);
return(true);
nope :;
Console.WriteLine("Failed..");
serial.Write("NOPE");
return(false);
} // PCOPEN_103
// PCClose
if (funcCode == PCDrvCodes.PCCLOSE_104)
{
serial.Write("OKAY");
// unirom sends extra params to save kernel
// space by grouping similar commands together.
UInt32 handle = TransferLogic.read32();
UInt32 unused1 = TransferLogic.read32();
UInt32 unused2 = TransferLogic.read32();
Console.WriteLine($"PCClose( {handle} ) unusedParams: {unused1},{unused2}");
PCFile f = GetOpenFile(handle);
try{
if (f == null)
{
Console.WriteLine("No such file... great success!");
serial.Write("OKAY"); // v0
serial.Write(BitConverter.GetBytes(0), 0, 4); // v1
return(true);
}
else
{
Console.WriteLine($"Closing file {f.fileName} with handle {f.handle}...");
serial.Write("OKAY"); // v0
serial.Write(BitConverter.GetBytes(f.handle), 0, 4); // v1 // let the garbage collector deal with it
ClosePCFile(f.handle);
return(true);
}
} catch (Exception e) {
Console.WriteLine("Error closing file..." + e);
serial.Write("NOPE"); // v0
// don't need to send v1
return(false);
}
} // PCCLOSE_104
// PCRead
if (funcCode == PCDrvCodes.PCREAD_105)
{
serial.Write("OKAY");
// unirom sends extra params to save kernel
// space by grouping similar commands together,
// so 'memaddr' is for debugging only.
// PCRead() takes (handle, buff*, len )
// but interally passes it to _SN_Read as
// ( 0, handle, len, buff* ), essentially
// shuffling regs A0,A1,A2 into A1,A3,A2.
// or just ( handle, len, buff* ). lol.
UInt32 handle = TransferLogic.read32();
int inLength = (int)TransferLogic.read32();
UInt32 memaddr = TransferLogic.read32(); // not used, debugging only
//Console.WriteLine( $"PCRead( {handle}, len={inLength}, dbg=0x{memaddr.ToString("X")} )" );
PCFile pcFile = GetOpenFile(handle);
Console.WriteLine($"PCRead( {handle}, len=0x{inLength.ToString("X")} ); MemAddr=0x{memaddr.ToString("X")}, File={pcFile}");
if (pcFile == null)
{
Console.WriteLine($"No file with handle 0x{handle.ToString("X")}, returning!");
serial.Write("NOPE"); // v0
// don't need to send v1
return(false);
}
else
{
Console.WriteLine("Reading file " + pcFile.fileName);
}
long streamLength = 0;
try{
FileStream fs = pcFile.fileStream;
streamLength = fs.Length;
byte[] bytes = new byte[inLength];
int bytesRead = fs.Read(bytes, 0, inLength);
if (bytesRead <= 0)
{
//throw new Exception( "Read 0 bytes from the file.." );
Console.WriteLine("Warning - no bytes were read from the file - returning zeros...");
}
// if we returned fewer bytes than requested, no biggie, the byte array is already set
serial.Write("OKAY"); // v0
serial.Write(BitConverter.GetBytes(bytes.Length), 0, 4); // v1
// Then
UInt32 check = TransferLogic.CalculateChecksum(bytes, false);
serial.Write(BitConverter.GetBytes(check), 0, 4);
TransferLogic.WriteBytes(bytes, false, true);
// again the weird order reflects a desire to save space within the psx kernel
// and reuse some functions
} catch (Exception e) {
Console.WriteLine($"Error reading file {pcFile.fileName} at pos={pcFile.fileStream.Position}, streamLength={streamLength} e={e}");
serial.Write("NOPE");
return(false);
}
} // PCREAD_105
// PCWrite
if (funcCode == PCDrvCodes.PCWRITE_106)
{
serial.Write("OKAY");
// PCWrite() takes (handle, buff*, len )
// but interally passes it to _SN_Write as
// ( 0, handle, len, buff* ), essentially
// shuffling regs A0,A1,A2 into A1,A3,A2.
// or just ( handle, len, buff* ). lol.
UInt32 handle = TransferLogic.read32();
int inLength = (int)TransferLogic.read32();
UInt32 memaddr = TransferLogic.read32(); // not used, debugging only
PCFile pcFile = GetOpenFile(handle);
if (pcFile == null)
{
Console.WriteLine($"No file with handle 0x{handle.ToString("X")}, returning!");
serial.Write("NOPE"); // v0
// don't need to send v1
return(false);
}
Console.WriteLine($"PCWrite( {handle}, len={inLength} ); fileName={pcFile.fileName} SourceAddr={memaddr.ToString( "X" )}, File={pcFile}");
if (pcFile.fileMode == PCFileMode.READONLY)
{
Console.WriteLine("Error: File is readonly!");
serial.Write("NOPE");
return(false);
}
serial.Write("OKAY");
try {
FileStream fs = pcFile.fileStream;
byte[] bytes = new byte[inLength];
bool didRead = TransferLogic.ReadBytes_Raw((UInt32)inLength, bytes);
if (!didRead)
{
throw new Exception("there was an error reading the stream from the psx!");
}
Console.WriteLine($"Read {inLength} bytes, flushing to {pcFile.fileName}...");
fs.Write(bytes, 0, inLength);
fs.Flush(true);
serial.Write("OKAY"); // v0
serial.Write(BitConverter.GetBytes(bytes.Length), 0, 4); // v1
// again the weird order reflects a desire to save space within the psx kernel
// and reuse some functions
} catch (Exception e) {
Console.WriteLine($"Error writing file {pcFile.fileName}, streamLength={inLength} e={e}");
serial.Write("NOPE");
return(false);
}
return(true);
} //PCWRITE 106
if (funcCode == PCDrvCodes.PCSEEK_107)
{
serial.Write("OKAY");
UInt32 handle = TransferLogic.read32();
int seekPos = (int)TransferLogic.read32();
SeekOrigin seekOrigin = (SeekOrigin)TransferLogic.read32();
PCFile pcFile = GetOpenFile(handle);
string fileName = pcFile != null ? pcFile.fileName : "";
Console.WriteLine($"PCSeek file {handle} to {seekPos}, type={seekOrigin}, fileName={fileName}");
if (pcFile == null)
{
Console.WriteLine("Error: There is no file with handle 0x" + handle.ToString("X"));
serial.Write("NOPE");
return(false);
}
// Let's actually open the file and seek it to see if we bump into any issues
try {
FileStream fs = pcFile.fileStream;
//fs.Seek( pcFile.filePointer, pcFile.seekMode );
fs.Seek(seekPos, seekOrigin);
Console.WriteLine("Seeked position " + fs.Position);
serial.Write("OKAY");
serial.Write(BitConverter.GetBytes(fs.Position), 0, 4);
} catch (System.Exception e) {
Console.WriteLine($"Exception when seeking file {handle}, e={e}");
serial.Write("NOPE");
return(false);
}
} //PCSEEK_107
return(true);
}