--- a/Output/pjrcUSB/arm/usb_dev.c	Fri May 13 14:38:46 2016 -0700
+++ b/Output/pjrcUSB/arm/usb_dev.c	Mon May 16 23:25:08 2016 -0700
@@ -589,10 +589,23 @@
 		USBKeys_Protocol = setup.wValue & 0xFF; // 0 - Boot Mode, 1 - NKRO Mode
 		goto send;
 
+	case 0x03A1: /// HID GET_PROTOCOL
+		#ifdef UART_DEBUG
+		print("GET_PROTOCOL - ");
+		printHex( setup.wValue );
+		print(" - ");
+		printHex( USBKeys_Protocol );
+		print(NL);
+		#endif
+		reply_buffer[0] = USBKeys_Protocol;
+		datalen = 1;
+		goto send;
+
 	// case 0xC940:
 	default:
 		#ifdef UART_DEBUG_UNKNOWN
 		print("UNKNOWN");
+		print(NL);
 		#endif
 		endpoint0_stall();
 		return;

--- a/Output/usbMuxUart/output_com.c	Fri May 13 14:38:46 2016 -0700
+++ b/Output/usbMuxUart/output_com.c	Mon May 16 23:25:08 2016 -0700
@@ -39,6 +39,9 @@
 #include <arm/usb_serial.h>
 #endif
 
+// KLL
+#include <kll_defs.h>
+
 // Local Includes
 #include "output_com.h"
 
@@ -117,15 +120,25 @@
 // 1=num lock, 2=caps lock, 4=scroll lock, 8=compose, 16=kana
 volatile uint8_t  USBKeys_LEDs = 0;
 
+// Currently pressed mouse buttons, bitmask, 0 represents no buttons pressed
+volatile uint16_t USBMouse_Buttons = 0;
+
+// Relative mouse axis movement, stores pending movement
+volatile uint16_t USBMouse_Relative_x = 0;
+volatile uint16_t USBMouse_Relative_y = 0;
+
 // Protocol setting from the host.
 // 0 - Boot Mode
 // 1 - NKRO Mode (Default, unless set by a BIOS or boot interface)
-volatile uint8_t  USBKeys_Protocol = 1;
+volatile uint8_t  USBKeys_Protocol = USBProtocol_define;
 
 // Indicate if USB should send update
 // OS only needs update if there has been a change in state
 USBKeyChangeState USBKeys_Changed = USBKeyChangeState_None;
 
+// Indicate if USB should send update
+USBMouseChangeState USBMouse_Changed = 0;
+
 // the idle configuration, how often we send the report to the
 // host (ms * 4) even when it hasn't changed
 uint8_t  USBKeys_Idle_Config = 125;
@@ -511,6 +524,63 @@
 	Output_firmwareReload();
 }
 
+// Sends a mouse command over the USB Output buffer
+// XXX This function *will* be changing in the future
+//     If you use it, be prepared that your .kll files will break in the future (post KLL 0.5)
+// Argument #1: USB Mouse Button (16 bit)
+// Argument #2: USB X Axis (16 bit) relative
+// Argument #3: USB Y Axis (16 bit) relative
+void Output_usbMouse_capability( uint8_t state, uint8_t stateType, uint8_t *args )
+{
+	// Display capability name
+	if ( stateType == 0xFF && state == 0xFF )
+	{
+		print("Output_usbMouse(mouseButton,relX,relY)");
+		return;
+	}
+
+	// Determine which mouse button was sent
+	// The USB spec defines up to a max of 0xFFFF buttons
+	// The usual are:
+	// 1 - Button 1 - (Primary)
+	// 2 - Button 2 - (Secondary)
+	// 3 - Button 3 - (Tertiary)
+	uint16_t mouse_button = *(uint16_t*)(&args[0]);
+
+	// X/Y Relative Axis
+	uint16_t mouse_x = *(uint16_t*)(&args[2]);
+	uint16_t mouse_y = *(uint16_t*)(&args[4]);
+
+	// Adjust for bit shift
+	uint16_t mouse_button_shift = mouse_button - 1;
+
+	// Only send mouse button if in press or hold state
+	if ( stateType == 0x00 && state == 0x03 ) // Release state
+	{
+		// Release
+		if ( mouse_button )
+			USBMouse_Buttons &= ~(1 << mouse_button_shift);
+	}
+	else
+	{
+		// Press or hold
+		if ( mouse_button )
+			USBMouse_Buttons |= (1 << mouse_button_shift);
+
+		if ( mouse_x )
+			USBMouse_Relative_x = mouse_x;
+		if ( mouse_y )
+			USBMouse_Relative_y = mouse_y;
+	}
+
+	// Trigger updates
+	if ( mouse_button )
+		USBMouse_Changed |= USBMouseChangeState_Buttons;
+
+	if ( mouse_x || mouse_y )
+		USBMouse_Changed |= USBMouseChangeState_Relative;
+}
+
 
 
 // ----- Functions -----