Added command byte count to SCSI command mapping (#966)

* Extended mapping table with command byte count

* Terminate early if command is unknown

cpp/hal/bus.cpp

@@ -11,24 +11,18 @@
 #include "bus.h"
 
 using namespace std;
+using namespace scsi_defs;
 
 //---------------------------------------------------------------------------
 //
 // Get the number of bytes for a command
-// TODO Add the byte count to the enum value/command name mapping and remove the comparisons
 //
 //---------------------------------------------------------------------------
 int BUS::GetCommandByteCount(uint8_t opcode)
 {
-    if (opcode == 0x88 || opcode == 0x8A || opcode == 0x8F || opcode == 0x91 || opcode == 0x9E || opcode == 0x9F) {
-        return 16;
-    } else if (opcode == 0xA0) {
-        return 12;
-    } else if (opcode >= 0x20 && opcode <= 0x7D) {
-        return 10;
-    } else {
-        return 6;
-    }
+	const auto& mapping = command_mapping.find(static_cast<scsi_command>(opcode));
+
+	return mapping != command_mapping.end() ? mapping->second.first : 0;
 }
 
 //---------------------------------------------------------------------------

cpp/hal/bus.h

@@ -12,6 +12,7 @@
 #include "scsi.h"
 #include <cstdint>
 #include <array>
+#include <vector>
 #include <unordered_map>
 
 using namespace std;
@@ -97,7 +98,7 @@ public:
 	virtual bool GetDP() const = 0;			// Get parity signal
 
 	virtual uint32_t Acquire() = 0;
-	virtual int CommandHandShake(uint8_t *buf) = 0;
+	virtual int CommandHandShake(vector<uint8_t>&) = 0;
 	virtual int ReceiveHandShake(uint8_t *buf, int count) = 0;
 	virtual int SendHandShake(uint8_t *buf, int count, int delay_after_bytes) = 0;
 

cpp/hal/gpiobus.cpp

@@ -431,7 +431,7 @@ bool GPIOBUS::GetDP() const
 //	Receive command handshake
 //
 //---------------------------------------------------------------------------
-int GPIOBUS::CommandHandShake(uint8_t *buf)
+int GPIOBUS::CommandHandShake(vector<uint8_t>& buf)
 {
     GPIO_FUNCTION_TRACE
     // Only works in TARGET mode
@@ -451,7 +451,7 @@ int GPIOBUS::CommandHandShake(uint8_t *buf)
     SysTimer::SleepNsec(SCSI_DELAY_BUS_SETTLE_DELAY_NS);
 
     // Get data
-    *buf = GetDAT();
+    buf[0] = GetDAT();
 
     // Disable REQ signal
     SetSignal(PIN_REQ, OFF);
@@ -480,7 +480,7 @@ int GPIOBUS::CommandHandShake(uint8_t *buf)
     // semantics. I fact, these semantics have become a standard in the Atari world.
 
     // RaSCSI becomes ICD compatible by ignoring the prepended $1F byte before processing the CDB.
-    if (*buf == 0x1F) {
+    if (buf[0] == 0x1F) {
         SetSignal(PIN_REQ, ON);
 
         ret = WaitSignal(PIN_ACK, ON);
@@ -488,7 +488,7 @@ int GPIOBUS::CommandHandShake(uint8_t *buf)
         SysTimer::SleepNsec(SCSI_DELAY_BUS_SETTLE_DELAY_NS);
 
         // Get the actual SCSI command
-        *buf = GetDAT();
+        buf[0] = GetDAT();
 
         SetSignal(PIN_REQ, OFF);
 
@@ -505,14 +505,20 @@ int GPIOBUS::CommandHandShake(uint8_t *buf)
         }
     }
 
-    const int command_byte_count = GetCommandByteCount(*buf);
+    const int command_byte_count = GetCommandByteCount(buf[0]);
+    if (command_byte_count == 0) {
+    	EnableIRQ();
 
-    // Increment buffer pointer
-    buf++;
+    	return 0;
+    }
+
+    int offset = 0;
 
     int bytes_received;
     for (bytes_received = 1; bytes_received < command_byte_count; bytes_received++) {
-        // Assert REQ signal
+    	++offset;
+
+    	// Assert REQ signal
         SetSignal(PIN_REQ, ON);
 
         // Wait for ACK signal
@@ -522,7 +528,7 @@ int GPIOBUS::CommandHandShake(uint8_t *buf)
         SysTimer::SleepNsec(SCSI_DELAY_BUS_SETTLE_DELAY_NS);
 
         // Get data
-        *buf = GetDAT();
+        buf[offset] = GetDAT();
 
         // Clear the REQ signal
         SetSignal(PIN_REQ, OFF);
@@ -539,9 +545,6 @@ int GPIOBUS::CommandHandShake(uint8_t *buf)
         if (!ret) {
             break;
         }
-
-        // Advance the buffer pointer to receive the next byte
-        buf++;
     }
 
     EnableIRQ();

cpp/hal/gpiobus.h

@@ -15,6 +15,7 @@
 #include "scsi.h"
 #include "bus.h"
 #include <array>
+#include <vector>
 
 #ifdef __linux__
 #include <linux/gpio.h>
@@ -332,7 +333,7 @@ class GPIOBUS : public BUS
     // Set REQ signal
     bool GetDP() const override;
     // Get Data parity signal
-    int CommandHandShake(uint8_t *buf) override;
+    int CommandHandShake(vector<uint8_t>&) override;
     // Command receive handshake
     int ReceiveHandShake(uint8_t *buf, int count) override;
     // Data receive handshake