BootloaderDFU.c 21.5 KB
Newer Older
1
2
3
/*
             LUFA Library
     Copyright (C) Dean Camera, 2010.
4

5
6
7
8
9
10
11
  dean [at] fourwalledcubicle [dot] com
      www.fourwalledcubicle.com
*/

/*
  Copyright 2010  Dean Camera (dean [at] fourwalledcubicle [dot] com)

12
  Permission to use, copy, modify, distribute, and sell this
13
  software and its documentation for any purpose is hereby granted
14
  without fee, provided that the above copyright notice appear in
15
  all copies and that both that the copyright notice and this
16
17
18
  permission notice and warranty disclaimer appear in supporting
  documentation, and that the name of the author not be used in
  advertising or publicity pertaining to distribution of the
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
  software without specific, written prior permission.

  The author disclaim all warranties with regard to this
  software, including all implied warranties of merchantability
  and fitness.  In no event shall the author be liable for any
  special, indirect or consequential damages or any damages
  whatsoever resulting from loss of use, data or profits, whether
  in an action of contract, negligence or other tortious action,
  arising out of or in connection with the use or performance of
  this software.
*/

/** \file
 *
 *  Main source file for the DFU class bootloader. This file contains the complete bootloader logic.
 */

#define  INCLUDE_FROM_BOOTLOADER_C
#include "BootloaderDFU.h"

/** Flag to indicate if the bootloader is currently running in secure mode, disallowing memory operations
 *  other than erase. This is initially set to the value set by SECURE_MODE, and cleared by the bootloader
 *  once a memory erase has completed.
 */
bool IsSecure      = SECURE_MODE;

/** Flag to indicate if the bootloader should be running, or should exit and allow the application code to run
 *  via a soft reset. When cleared, the bootloader will abort, the USB interface will shut down and the application
 *  jumped to via an indirect jump to location 0x0000 (or other location specified by the host).
 */
bool RunBootloader = true;

/** Flag to indicate if the bootloader is waiting to exit. When the host requests the bootloader to exit and
 *  jump to the application address it specifies, it sends two sequential commands which must be properly
 *  acknowledged. Upon reception of the first the RunBootloader flag is cleared and the WaitForExit flag is set,
 *  causing the bootloader to wait for the final exit command before shutting down.
 */
bool WaitForExit = false;

/** Current DFU state machine state, one of the values in the DFU_State_t enum. */
uint8_t DFU_State = dfuIDLE;

/** Status code of the last executed DFU command. This is set to one of the values in the DFU_Status_t enum after
 *  each operation, and returned to the host when a Get Status DFU request is issued.
 */
uint8_t DFU_Status = OK;

/** Data containing the DFU command sent from the host. */
DFU_Command_t SentCommand;

/** Response to the last issued Read Data DFU command. Unlike other DFU commands, the read command
 *  requires a single byte response from the bootloader containing the read data when the next DFU_UPLOAD command
 *  is issued by the host.
 */
uint8_t ResponseByte;

/** Pointer to the start of the user application. By default this is 0x0000 (the reset vector), however the host
 *  may specify an alternate address when issuing the application soft-start command.
 */
AppPtr_t AppStartPtr = (AppPtr_t)0x0000;

/** 64-bit flash page number. This is concatenated with the current 16-bit address on USB AVRs containing more than
 *  64KB of flash memory.
 */
uint8_t Flash64KBPage = 0;

/** Memory start address, indicating the current address in the memory being addressed (either FLASH or EEPROM
 *  depending on the issued command from the host).
 */
uint16_t StartAddr = 0x0000;

/** Memory end address, indicating the end address to read to/write from in the memory being addressed (either FLASH
 *  of EEPROM depending on the issued command from the host).
 */
uint16_t EndAddr = 0x0000;


96
/** Main program entry point. This routine configures the hardware required by the bootloader, then continuously
97
98
99
100
101
102
103
 *  runs the bootloader processing routine until instructed to soft-exit, or hard-reset via the watchdog to start
 *  the loaded application code.
 */
int main(void)
{
	/* Configure hardware required by the bootloader */
	SetupHardware();
104

105
106
107
108
109
110
	/* Enable global interrupts so that the USB stack can function */
	sei();

	/* Run the USB management task while the bootloader is supposed to be running */
	while (RunBootloader || WaitForExit)
	  USB_USBTask();
111

112
113
	/* Reset configured hardware back to their original states for the user application */
	ResetHardware();
114

115
116
117
118
119
120
121
122
123
124
125
126
127
	/* Start the user application */
	AppStartPtr();
}

/** Configures all hardware required for the bootloader. */
void SetupHardware(void)
{
	/* Disable watchdog if enabled by bootloader/fuses */
	MCUSR &= ~(1 << WDRF);
	wdt_disable();

	/* Disable clock division */
	clock_prescale_set(clock_div_1);
128

129
130
131
132
133
134
135
136
137
138
139
140
141
	/* Relocate the interrupt vector table to the bootloader section */
	MCUCR = (1 << IVCE);
	MCUCR = (1 << IVSEL);

	/* Initialize the USB subsystem */
	USB_Init();
}

/** Resets all configured hardware required for the bootloader back to their original states. */
void ResetHardware(void)
{
	/* Shut down the USB subsystem */
	USB_ShutDown();
142

143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
	/* Relocate the interrupt vector table back to the application section */
	MCUCR = (1 << IVCE);
	MCUCR = 0;
}

/** Event handler for the USB_UnhandledControlRequest event. This is used to catch standard and class specific
 *  control requests that are not handled internally by the USB library (including the DFU commands, which are
 *  all issued via the control endpoint), so that they can be handled appropriately for the application.
 */
void EVENT_USB_Device_UnhandledControlRequest(void)
{
	/* Get the size of the command and data from the wLength value */
	SentCommand.DataSize = USB_ControlRequest.wLength;

	switch (USB_ControlRequest.bRequest)
	{
159
		case REQ_DFU_DNLOAD:
160
			Endpoint_ClearSETUP();
161

162
163
164
165
166
			/* Check if bootloader is waiting to terminate */
			if (WaitForExit)
			{
				/* Bootloader is terminating - process last received command */
				ProcessBootloaderCommand();
167

168
169
170
				/* Indicate that the last command has now been processed - free to exit bootloader */
				WaitForExit = false;
			}
171

172
173
174
175
			/* If the request has a data stage, load it into the command struct */
			if (SentCommand.DataSize)
			{
				while (!(Endpoint_IsOUTReceived()))
176
				{
177
178
179
180
181
182
					if (USB_DeviceState == DEVICE_STATE_Unattached)
					  return;
				}

				/* First byte of the data stage is the DNLOAD request's command */
				SentCommand.Command = Endpoint_Read_Byte();
183

184
185
				/* One byte of the data stage is the command, so subtract it from the total data bytes */
				SentCommand.DataSize--;
186

187
188
189
190
191
192
193
				/* Load in the rest of the data stage as command parameters */
				for (uint8_t DataByte = 0; (DataByte < sizeof(SentCommand.Data)) &&
				     Endpoint_BytesInEndpoint(); DataByte++)
				{
					SentCommand.Data[DataByte] = Endpoint_Read_Byte();
					SentCommand.DataSize--;
				}
194

195
196
197
				/* Process the command */
				ProcessBootloaderCommand();
			}
198

199
200
			/* Check if currently downloading firmware */
			if (DFU_State == dfuDNLOAD_IDLE)
201
			{
202
203
204
205
206
207
208
209
210
211
212
				if (!(SentCommand.DataSize))
				{
					DFU_State = dfuIDLE;
				}
				else
				{
					/* Throw away the filler bytes before the start of the firmware */
					DiscardFillerBytes(DFU_FILLER_BYTES_SIZE);

					/* Throw away the packet alignment filler bytes before the start of the firmware */
					DiscardFillerBytes(StartAddr % FIXED_CONTROL_ENDPOINT_SIZE);
213

214
215
					/* Calculate the number of bytes remaining to be written */
					uint16_t BytesRemaining = ((EndAddr - StartAddr) + 1);
216

217
218
219
220
					if (IS_ONEBYTE_COMMAND(SentCommand.Data, 0x00))        // Write flash
					{
						/* Calculate the number of words to be written from the number of bytes to be written */
						uint16_t WordsRemaining = (BytesRemaining >> 1);
221

222
223
224
225
226
						union
						{
							uint16_t Words[2];
							uint32_t Long;
						} CurrFlashAddress                 = {.Words = {StartAddr, Flash64KBPage}};
227

228
229
230
231
232
233
234
235
236
237
238
						uint32_t CurrFlashPageStartAddress = CurrFlashAddress.Long;
						uint8_t  WordsInFlashPage          = 0;

						while (WordsRemaining--)
						{
							/* Check if endpoint is empty - if so clear it and wait until ready for next packet */
							if (!(Endpoint_BytesInEndpoint()))
							{
								Endpoint_ClearOUT();

								while (!(Endpoint_IsOUTReceived()))
239
								{
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
									if (USB_DeviceState == DEVICE_STATE_Unattached)
									  return;
								}
							}

							/* Write the next word into the current flash page */
							boot_page_fill(CurrFlashAddress.Long, Endpoint_Read_Word_LE());

							/* Adjust counters */
							WordsInFlashPage      += 1;
							CurrFlashAddress.Long += 2;

							/* See if an entire page has been written to the flash page buffer */
							if ((WordsInFlashPage == (SPM_PAGESIZE >> 1)) || !(WordsRemaining))
							{
								/* Commit the flash page to memory */
								boot_page_write(CurrFlashPageStartAddress);
								boot_spm_busy_wait();
258

259
260
261
262
263
264
265
266
267
268
269
270
								/* Check if programming incomplete */
								if (WordsRemaining)
								{
									CurrFlashPageStartAddress = CurrFlashAddress.Long;
									WordsInFlashPage          = 0;

									/* Erase next page's temp buffer */
									boot_page_erase(CurrFlashAddress.Long);
									boot_spm_busy_wait();
								}
							}
						}
271

272
273
						/* Once programming complete, start address equals the end address */
						StartAddr = EndAddr;
274

275
276
277
278
279
280
281
282
283
284
285
286
287
						/* Re-enable the RWW section of flash */
						boot_rww_enable();
					}
					else                                                   // Write EEPROM
					{
						while (BytesRemaining--)
						{
							/* Check if endpoint is empty - if so clear it and wait until ready for next packet */
							if (!(Endpoint_BytesInEndpoint()))
							{
								Endpoint_ClearOUT();

								while (!(Endpoint_IsOUTReceived()))
288
								{
289
290
291
292
293
294
295
									if (USB_DeviceState == DEVICE_STATE_Unattached)
									  return;
								}
							}

							/* Read the byte from the USB interface and write to to the EEPROM */
							eeprom_write_byte((uint8_t*)StartAddr, Endpoint_Read_Byte());
296

297
298
299
300
							/* Adjust counters */
							StartAddr++;
						}
					}
301

302
303
304
305
306
307
308
309
310
311
					/* Throw away the currently unused DFU file suffix */
					DiscardFillerBytes(DFU_FILE_SUFFIX_SIZE);
				}
			}

			Endpoint_ClearOUT();

			Endpoint_ClearStatusStage();

			break;
312
		case REQ_DFU_UPLOAD:
313
314
315
			Endpoint_ClearSETUP();

			while (!(Endpoint_IsINReady()))
316
			{
317
318
319
				if (USB_DeviceState == DEVICE_STATE_Unattached)
				  return;
			}
320

321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
			if (DFU_State != dfuUPLOAD_IDLE)
			{
				if ((DFU_State == dfuERROR) && IS_ONEBYTE_COMMAND(SentCommand.Data, 0x01))       // Blank Check
				{
					/* Blank checking is performed in the DFU_DNLOAD request - if we get here we've told the host
					   that the memory isn't blank, and the host is requesting the first non-blank address */
					Endpoint_Write_Word_LE(StartAddr);
				}
				else
				{
					/* Idle state upload - send response to last issued command */
					Endpoint_Write_Byte(ResponseByte);
				}
			}
			else
			{
				/* Determine the number of bytes remaining in the current block */
				uint16_t BytesRemaining = ((EndAddr - StartAddr) + 1);

				if (IS_ONEBYTE_COMMAND(SentCommand.Data, 0x00))            // Read FLASH
				{
					/* Calculate the number of words to be written from the number of bytes to be written */
					uint16_t WordsRemaining = (BytesRemaining >> 1);

					union
					{
						uint16_t Words[2];
						uint32_t Long;
					} CurrFlashAddress = {.Words = {StartAddr, Flash64KBPage}};

					while (WordsRemaining--)
					{
						/* Check if endpoint is full - if so clear it and wait until ready for next packet */
						if (Endpoint_BytesInEndpoint() == FIXED_CONTROL_ENDPOINT_SIZE)
						{
							Endpoint_ClearIN();

							while (!(Endpoint_IsINReady()))
359
							{
360
361
362
363
364
365
366
367
368
								if (USB_DeviceState == DEVICE_STATE_Unattached)
								  return;
							}
						}

						/* Read the flash word and send it via USB to the host */
						#if (FLASHEND > 0xFFFF)
							Endpoint_Write_Word_LE(pgm_read_word_far(CurrFlashAddress.Long));
						#else
369
							Endpoint_Write_Word_LE(pgm_read_word(CurrFlashAddress.Long));
370
371
372
373
374
						#endif

						/* Adjust counters */
						CurrFlashAddress.Long += 2;
					}
375

376
377
378
379
380
381
382
383
384
385
386
					/* Once reading is complete, start address equals the end address */
					StartAddr = EndAddr;
				}
				else if (IS_ONEBYTE_COMMAND(SentCommand.Data, 0x02))       // Read EEPROM
				{
					while (BytesRemaining--)
					{
						/* Check if endpoint is full - if so clear it and wait until ready for next packet */
						if (Endpoint_BytesInEndpoint() == FIXED_CONTROL_ENDPOINT_SIZE)
						{
							Endpoint_ClearIN();
387

388
							while (!(Endpoint_IsINReady()))
389
							{
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
								if (USB_DeviceState == DEVICE_STATE_Unattached)
								  return;
							}
						}

						/* Read the EEPROM byte and send it via USB to the host */
						Endpoint_Write_Byte(eeprom_read_byte((uint8_t*)StartAddr));

						/* Adjust counters */
						StartAddr++;
					}
				}

				/* Return to idle state */
				DFU_State = dfuIDLE;
			}

			Endpoint_ClearIN();

			Endpoint_ClearStatusStage();
			break;
411
		case REQ_DFU_GETSTATUS:
412
			Endpoint_ClearSETUP();
413

414
415
			/* Write 8-bit status value */
			Endpoint_Write_Byte(DFU_Status);
416

417
418
419
			/* Write 24-bit poll timeout value */
			Endpoint_Write_Byte(0);
			Endpoint_Write_Word_LE(0);
420

421
422
423
424
425
426
427
			/* Write 8-bit state value */
			Endpoint_Write_Byte(DFU_State);

			/* Write 8-bit state string ID number */
			Endpoint_Write_Byte(0);

			Endpoint_ClearIN();
428

429
			Endpoint_ClearStatusStage();
430
			break;
431
		case REQ_DFU_CLRSTATUS:
432
			Endpoint_ClearSETUP();
433

434
435
436
437
438
			/* Reset the status value variable to the default OK status */
			DFU_Status = OK;

			Endpoint_ClearStatusStage();
			break;
439
		case REQ_DFU_GETSTATE:
440
			Endpoint_ClearSETUP();
441

442
443
			/* Write the current device state to the endpoint */
			Endpoint_Write_Byte(DFU_State);
444

445
			Endpoint_ClearIN();
446

447
448
			Endpoint_ClearStatusStage();
			break;
449
		case REQ_DFU_ABORT:
450
			Endpoint_ClearSETUP();
451

452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
			/* Reset the current state variable to the default idle state */
			DFU_State = dfuIDLE;

			Endpoint_ClearStatusStage();
			break;
	}
}

/** Routine to discard the specified number of bytes from the control endpoint stream. This is used to
 *  discard unused bytes in the stream from the host, including the memory program block suffix.
 *
 *  \param[in] NumberOfBytes  Number of bytes to discard from the host from the control endpoint
 */
static void DiscardFillerBytes(uint8_t NumberOfBytes)
{
	while (NumberOfBytes--)
	{
		if (!(Endpoint_BytesInEndpoint()))
		{
			Endpoint_ClearOUT();

			/* Wait until next data packet received */
			while (!(Endpoint_IsOUTReceived()))
475
			{
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
				if (USB_DeviceState == DEVICE_STATE_Unattached)
				  return;
			}
		}
		else
		{
			Endpoint_Discard_Byte();
		}
	}
}

/** Routine to process an issued command from the host, via a DFU_DNLOAD request wrapper. This routine ensures
 *  that the command is allowed based on the current secure mode flag value, and passes the command off to the
 *  appropriate handler function.
 */
static void ProcessBootloaderCommand(void)
{
	/* Check if device is in secure mode */
	if (IsSecure)
	{
		/* Don't process command unless it is a READ or chip erase command */
		if (!(((SentCommand.Command == COMMAND_WRITE)             &&
		        IS_TWOBYTE_COMMAND(SentCommand.Data, 0x00, 0xFF)) ||
			   (SentCommand.Command == COMMAND_READ)))
		{
			/* Set the state and status variables to indicate the error */
			DFU_State  = dfuERROR;
			DFU_Status = errWRITE;
504

505
506
			/* Stall command */
			Endpoint_StallTransaction();
507

508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
			/* Don't process the command */
			return;
		}
	}

	/* Dispatch the required command processing routine based on the command type */
	switch (SentCommand.Command)
	{
		case COMMAND_PROG_START:
			ProcessMemProgCommand();
			break;
		case COMMAND_DISP_DATA:
			ProcessMemReadCommand();
			break;
		case COMMAND_WRITE:
			ProcessWriteCommand();
			break;
		case COMMAND_READ:
			ProcessReadCommand();
			break;
		case COMMAND_CHANGE_BASE_ADDR:
			if (IS_TWOBYTE_COMMAND(SentCommand.Data, 0x03, 0x00))              // Set 64KB flash page command
			  Flash64KBPage = SentCommand.Data[2];

			break;
	}
}

/** Routine to concatenate the given pair of 16-bit memory start and end addresses from the host, and store them
 *  in the StartAddr and EndAddr global variables.
 */
static void LoadStartEndAddresses(void)
{
	union
	{
		uint8_t  Bytes[2];
		uint16_t Word;
	} Address[2] = {{.Bytes = {SentCommand.Data[2], SentCommand.Data[1]}},
	                {.Bytes = {SentCommand.Data[4], SentCommand.Data[3]}}};
547

548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
	/* Load in the start and ending read addresses from the sent data packet */
	StartAddr = Address[0].Word;
	EndAddr   = Address[1].Word;
}

/** Handler for a Memory Program command issued by the host. This routine handles the preparations needed
 *  to write subsequent data from the host into the specified memory.
 */
static void ProcessMemProgCommand(void)
{
	if (IS_ONEBYTE_COMMAND(SentCommand.Data, 0x00) ||                          // Write FLASH command
	    IS_ONEBYTE_COMMAND(SentCommand.Data, 0x01))                            // Write EEPROM command
	{
		/* Load in the start and ending read addresses */
		LoadStartEndAddresses();
563

564
565
566
567
568
569
570
571
		/* If FLASH is being written to, we need to pre-erase the first page to write to */
		if (IS_ONEBYTE_COMMAND(SentCommand.Data, 0x00))
		{
			union
			{
				uint16_t Words[2];
				uint32_t Long;
			} CurrFlashAddress = {.Words = {StartAddr, Flash64KBPage}};
572

573
574
575
576
			/* Erase the current page's temp buffer */
			boot_page_erase(CurrFlashAddress.Long);
			boot_spm_busy_wait();
		}
577

578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
		/* Set the state so that the next DNLOAD requests reads in the firmware */
		DFU_State = dfuDNLOAD_IDLE;
	}
}

/** Handler for a Memory Read command issued by the host. This routine handles the preparations needed
 *  to read subsequent data from the specified memory out to the host, as well as implementing the memory
 *  blank check command.
 */
static void ProcessMemReadCommand(void)
{
	if (IS_ONEBYTE_COMMAND(SentCommand.Data, 0x00) ||                          // Read FLASH command
        IS_ONEBYTE_COMMAND(SentCommand.Data, 0x02))                            // Read EEPROM command
	{
		/* Load in the start and ending read addresses */
		LoadStartEndAddresses();

		/* Set the state so that the next UPLOAD requests read out the firmware */
		DFU_State = dfuUPLOAD_IDLE;
	}
	else if (IS_ONEBYTE_COMMAND(SentCommand.Data, 0x01))                       // Blank check FLASH command
	{
		uint32_t CurrFlashAddress = 0;

		while (CurrFlashAddress < BOOT_START_ADDR)
		{
			/* Check if the current byte is not blank */
			#if (FLASHEND > 0xFFFF)
			if (pgm_read_byte_far(CurrFlashAddress) != 0xFF)
			#else
			if (pgm_read_byte(CurrFlashAddress) != 0xFF)
			#endif
			{
				/* Save the location of the first non-blank byte for response back to the host */
				Flash64KBPage = (CurrFlashAddress >> 16);
				StartAddr     = CurrFlashAddress;
614

615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
				/* Set state and status variables to the appropriate error values */
				DFU_State  = dfuERROR;
				DFU_Status = errCHECK_ERASED;

				break;
			}

			CurrFlashAddress++;
		}
	}
}

/** Handler for a Data Write command issued by the host. This routine handles non-programming commands such as
 *  bootloader exit (both via software jumps and hardware watchdog resets) and flash memory erasure.
 */
static void ProcessWriteCommand(void)
{
	if (IS_ONEBYTE_COMMAND(SentCommand.Data, 0x03))                            // Start application
	{
		/* Indicate that the bootloader is terminating */
		WaitForExit = true;

637
638
		/* Check if data supplied for the Start Program command - no data executes the program */
		if (SentCommand.DataSize)
639
		{
640
			if (SentCommand.Data[1] == 0x01)                                   // Start via jump
641
642
643
644
645
646
647
			{
				union
				{
					uint8_t  Bytes[2];
					AppPtr_t FuncPtr;
				} Address = {.Bytes = {SentCommand.Data[4], SentCommand.Data[3]}};

648
				/* Load in the jump address into the application start address pointer */
649
				AppStartPtr = Address.FuncPtr;
650
651
652
653
654
655
656
657
658
659
660
			}
		}
		else
		{
			if (SentCommand.Data[1] == 0x00)                                   // Start via watchdog
			{
				/* Start the watchdog to reset the AVR once the communications are finalized */
				wdt_enable(WDTO_250MS);
			}
			else                                                               // Start via jump
			{
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
				/* Set the flag to terminate the bootloader at next opportunity */
				RunBootloader = false;
			}
		}
	}
	else if (IS_TWOBYTE_COMMAND(SentCommand.Data, 0x00, 0xFF))                 // Erase flash
	{
		uint32_t CurrFlashAddress = 0;

		/* Clear the application section of flash */
		while (CurrFlashAddress < BOOT_START_ADDR)
		{
			boot_page_erase(CurrFlashAddress);
			boot_spm_busy_wait();
			boot_page_write(CurrFlashAddress);
			boot_spm_busy_wait();

			CurrFlashAddress += SPM_PAGESIZE;
		}

		/* Re-enable the RWW section of flash as writing to the flash locks it out */
		boot_rww_enable();
683

684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
		/* Memory has been erased, reset the security bit so that programming/reading is allowed */
		IsSecure = false;
	}
}

/** Handler for a Data Read command issued by the host. This routine handles bootloader information retrieval
 *  commands such as device signature and bootloader version retrieval.
 */
static void ProcessReadCommand(void)
{
	const uint8_t BootloaderInfo[3] = {BOOTLOADER_VERSION, BOOTLOADER_ID_BYTE1, BOOTLOADER_ID_BYTE2};
	const uint8_t SignatureInfo[3]  = {AVR_SIGNATURE_1,    AVR_SIGNATURE_2,     AVR_SIGNATURE_3};

	uint8_t DataIndexToRead = SentCommand.Data[1];

	if (IS_ONEBYTE_COMMAND(SentCommand.Data, 0x00))                         // Read bootloader info
	  ResponseByte = BootloaderInfo[DataIndexToRead];
	else if (IS_ONEBYTE_COMMAND(SentCommand.Data, 0x01))                    // Read signature byte
	  ResponseByte = SignatureInfo[DataIndexToRead - 0x30];
}
704