Improve XEBEC vendor Request Sense responses

Handle all sense codes that the current code can produce.
Xebec has more possible sense codes but they currently aren't needed.

Since there is no direct mapping from SCSI sense data to the Xebec
proprietary sense data, the codes were matched as closely as possible.

Signed-off-by: Jernej Jakob <jernej.jakob@gmail.com>

lib/SCSI2SD/src/firmware/scsi.c

@@ -382,14 +382,57 @@ static void process_Command()
 		{
 			// Completely non-standard
 			allocLength = 4;
-			if (scsiDev.target->sense.code == NO_SENSE)
-				scsiDev.data[0] = 0;
-			else if (scsiDev.target->sense.code == ILLEGAL_REQUEST)
-				scsiDev.data[0] = 0x20; // Illegal command
-			else if (scsiDev.target->sense.code == NOT_READY)
-				scsiDev.data[0] = 0x04; // Drive not ready
-			else
-				scsiDev.data[0] = 0x11;  // Uncorrectable data error
+
+			switch (scsiDev.target->sense.code)
+			{
+				case NO_SENSE:
+					scsiDev.data[0] = 0;
+					break;
+				case MEDIUM_ERROR:
+					switch (scsiDev.target->sense.asc)
+					{
+						case NO_SEEK_COMPLETE:
+							scsiDev.data[0] = 0x15; // Seek Error
+							break;
+						case WRITE_ERROR_AUTO_REALLOCATION_FAILED:
+							scsiDev.data[0] = 0x03; // Write fault
+							break;
+						default:
+						case UNRECOVERED_READ_ERROR:
+							scsiDev.data[0] = 0x11; // Uncorrectable read error
+							break;
+					}
+					break;
+				case ILLEGAL_REQUEST:
+					switch (scsiDev.target->sense.asc)
+					{
+						case LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE:
+							scsiDev.data[0] = 0x14; // Target sector not found
+							break;
+						case WRITE_PROTECTED:
+							scsiDev.data[0] = 0x03; // Write fault
+							break;
+						default:
+							scsiDev.data[0] = 0x20; // Invalid command
+							break;
+					}
+					break;
+				case NOT_READY:
+					switch (scsiDev.target->sense.asc)
+					{
+						default:
+						case MEDIUM_NOT_PRESENT:
+							scsiDev.data[0] = 0x04; // Drive not ready
+							break;
+						case LOGICAL_UNIT_NOT_READY_INITIALIZING_COMMAND_REQUIRED:
+							scsiDev.data[0] = 0x1A; // Format Error
+							break;
+					}
+					break;
+				default:
+					scsiDev.data[0] = 0x11;  // Uncorrectable data error
+					break;
+			}
 
 			scsiDev.data[1] = (scsiDev.cdb[1] & 0x20) | ((transfer.lba >> 16) & 0x1F);
 			scsiDev.data[2] = transfer.lba >> 8;