summaryrefslogtreecommitdiffstats
path: root/jedec.c
blob: 2542f3e67241c6e9f3d0f8a29a1cba7372bc6061 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
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
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
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
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
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
504
505
506
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
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
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
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
/*
 * This file is part of the flashrom project.
 *
 * Copyright (C) 2000 Silicon Integrated System Corporation
 * Copyright (C) 2006 Giampiero Giancipoli <gianci@email.it>
 * Copyright (C) 2006 coresystems GmbH <info@coresystems.de>
 * Copyright (C) 2007-2012 Carl-Daniel Hailfinger
 * Copyright (C) 2009 Sean Nelson <audiohacked@gmail.com>
 * Copyright (C) 2014 Stefan Tauner
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include "flash.h"
#include "chipdrivers.h"

#define MAX_REFLASH_TRIES 0x10
#define MASK_FULL 0xffff
#define MASK_2AA 0x7ff
#define MASK_AAA 0xfff

/* Check one byte for odd parity */
uint8_t oddparity(uint8_t val)
{
	val = (val ^ (val >> 4)) & 0xf;
	val = (val ^ (val >> 2)) & 0x3;
	return (val ^ (val >> 1)) & 0x1;
}

static void toggle_ready_jedec_common(const struct flashctx *flash, chipaddr dst, unsigned int delay)
{
	unsigned int i = 0;
	uint8_t tmp1, tmp2;

	tmp1 = chip_readb(flash, dst) & 0x40;

	while (i++ < 0xFFFFFFF) {
		if (delay)
			programmer_delay(delay);
		tmp2 = chip_readb(flash, dst) & 0x40;
		if (tmp1 == tmp2) {
			break;
		}
		tmp1 = tmp2;
	}
	if (i > 0x100000)
		msg_cdbg("%s: excessive loops, i=0x%x\n", __func__, i);
}

void toggle_ready_jedec(const struct flashctx *flash, chipaddr dst)
{
	toggle_ready_jedec_common(flash, dst, 0);
}

/* Some chips require a minimum delay between toggle bit reads.
 * The Winbond W39V040C wants 50 ms between reads on sector erase toggle,
 * but experiments show that 2 ms are already enough. Pick a safety factor
 * of 4 and use an 8 ms delay.
 * Given that erase is slow on all chips, it is recommended to use
 * toggle_ready_jedec_slow in erase functions.
 */
static void toggle_ready_jedec_slow(const struct flashctx *flash, chipaddr dst)
{
	toggle_ready_jedec_common(flash, dst, 8 * 1000);
}

void data_polling_jedec(const struct flashctx *flash, chipaddr dst,
			uint8_t data)
{
	unsigned int i = 0;
	uint8_t tmp;

	data &= 0x80;

	while (i++ < 0xFFFFFFF) {
		tmp = chip_readb(flash, dst) & 0x80;
		if (tmp == data) {
			break;
		}
	}
	if (i > 0x100000)
		msg_cdbg("%s: excessive loops, i=0x%x\n", __func__, i);
}

static unsigned int getaddrmask(const struct flashchip *chip)
{
	switch (chip->feature_bits & FEATURE_ADDR_MASK) {
	case FEATURE_ADDR_FULL:
		return MASK_FULL;
		break;
	case FEATURE_ADDR_2AA:
		return MASK_2AA;
		break;
	case FEATURE_ADDR_AAA:
		return MASK_AAA;
		break;
	default:
		msg_cerr("%s called with unknown mask\n", __func__);
		return 0;
		break;
	}
}

static void start_program_jedec_common(const struct flashctx *flash, unsigned int mask)
{
	chipaddr bios = flash->virtual_memory;
	bool shifted = (flash->chip->feature_bits & FEATURE_ADDR_SHIFTED);

	chip_writeb(flash, 0xAA, bios + ((shifted ? 0x2AAA : 0x5555) & mask));
	chip_writeb(flash, 0x55, bios + ((shifted ? 0x5555 : 0x2AAA) & mask));
	chip_writeb(flash, 0xA0, bios + ((shifted ? 0x2AAA : 0x5555) & mask));
}

int probe_jedec_29gl(struct flashctx *flash)
{
	unsigned int mask = getaddrmask(flash->chip);
	chipaddr bios = flash->virtual_memory;
	const struct flashchip *chip = flash->chip;

	/* Reset chip to a clean slate */
	chip_writeb(flash, 0xF0, bios + (0x5555 & mask));

	/* Issue JEDEC Product ID Entry command */
	chip_writeb(flash, 0xAA, bios + (0x5555 & mask));
	chip_writeb(flash, 0x55, bios + (0x2AAA & mask));
	chip_writeb(flash, 0x90, bios + (0x5555 & mask));

	/* Read product ID */
	// FIXME: Continuation loop, second byte is at word 0x100/byte 0x200
	uint32_t man_id = chip_readb(flash, bios + 0x00);
	uint32_t dev_id = (chip_readb(flash, bios + 0x01) << 16) |
			  (chip_readb(flash, bios + 0x0E) <<  8) |
			  (chip_readb(flash, bios + 0x0F) <<  0);

	/* Issue JEDEC Product ID Exit command */
	chip_writeb(flash, 0xF0, bios + (0x5555 & mask));

	msg_cdbg("%s: man_id 0x%02x, dev_id 0x%06x", __func__, man_id, dev_id);
	if (!oddparity(man_id))
		msg_cdbg(", man_id parity violation");

	/* Read the product ID location again. We should now see normal flash contents. */
	uint32_t flashcontent1 = chip_readb(flash, bios + 0x00); // FIXME: Continuation loop
	uint32_t flashcontent2 = (chip_readb(flash, bios + 0x01) << 16) |
				 (chip_readb(flash, bios + 0x0E) <<  8) |
				 (chip_readb(flash, bios + 0x0F) <<  0);

	if (man_id == flashcontent1)
		msg_cdbg(", man_id seems to be normal flash content");
	if (dev_id == flashcontent2)
		msg_cdbg(", dev_id seems to be normal flash content");

	msg_cdbg("\n");
	if (man_id != chip->manufacture_id || dev_id != chip->model_id)
		return 0;

	return 1;
}

static int probe_jedec_common(struct flashctx *flash, unsigned int mask)
{
	chipaddr bios = flash->virtual_memory;
	const struct flashchip *chip = flash->chip;
	bool shifted = (flash->chip->feature_bits & FEATURE_ADDR_SHIFTED);
	uint8_t id1, id2;
	uint32_t largeid1, largeid2;
	uint32_t flashcontent1, flashcontent2;
	unsigned int probe_timing_enter, probe_timing_exit;

	if (chip->probe_timing > 0)
		probe_timing_enter = probe_timing_exit = chip->probe_timing;
	else if (chip->probe_timing == TIMING_ZERO) { /* No delay. */
		probe_timing_enter = probe_timing_exit = 0;
	} else if (chip->probe_timing == TIMING_FIXME) { /* == _IGNORED */
		msg_cdbg("Chip lacks correct probe timing information, using default 10ms/40us. ");
		probe_timing_enter = 10000;
		probe_timing_exit = 40;
	} else {
		msg_cerr("Chip has negative value in probe_timing, failing without chip access\n");
		return 0;
	}

	/* Earlier probes might have been too fast for the chip to enter ID
	 * mode completely. Allow the chip to finish this before seeing a
	 * reset command.
	 */
	if (probe_timing_enter)
		programmer_delay(probe_timing_enter);
	/* Reset chip to a clean slate */
	if ((chip->feature_bits & FEATURE_RESET_MASK) == FEATURE_LONG_RESET)
	{
		chip_writeb(flash, 0xAA, bios + ((shifted ? 0x2AAA : 0x5555) & mask));
		if (probe_timing_exit)
			programmer_delay(10);
		chip_writeb(flash, 0x55, bios + ((shifted ? 0x5555 : 0x2AAA) & mask));
		if (probe_timing_exit)
			programmer_delay(10);
	}
	chip_writeb(flash, 0xF0, bios + ((shifted ? 0x2AAA : 0x5555) & mask));
	if (probe_timing_exit)
		programmer_delay(probe_timing_exit);

	/* Issue JEDEC Product ID Entry command */
	chip_writeb(flash, 0xAA, bios + ((shifted ? 0x2AAA : 0x5555) & mask));
	if (probe_timing_enter)
		programmer_delay(10);
	chip_writeb(flash, 0x55, bios + ((shifted ? 0x5555 : 0x2AAA) & mask));
	if (probe_timing_enter)
		programmer_delay(10);
	chip_writeb(flash, 0x90, bios + ((shifted ? 0x2AAA : 0x5555) & mask));
	if (probe_timing_enter)
		programmer_delay(probe_timing_enter);

	/* Read product ID */
	id1 = chip_readb(flash, bios + (0x00 << shifted));
	id2 = chip_readb(flash, bios + (0x01 << shifted));
	largeid1 = id1;
	largeid2 = id2;

	/* Check if it is a continuation ID, this should be a while loop. */
	if (id1 == 0x7F) {
		largeid1 <<= 8;
		id1 = chip_readb(flash, bios + 0x100);
		largeid1 |= id1;
	}
	if (id2 == 0x7F) {
		largeid2 <<= 8;
		id2 = chip_readb(flash, bios + 0x101);
		largeid2 |= id2;
	}

	/* Issue JEDEC Product ID Exit command */
	if ((chip->feature_bits & FEATURE_RESET_MASK) == FEATURE_LONG_RESET)
	{
		chip_writeb(flash, 0xAA, bios + ((shifted ? 0x2AAA : 0x5555) & mask));
		if (probe_timing_exit)
			programmer_delay(10);
		chip_writeb(flash, 0x55, bios + ((shifted ? 0x5555 : 0x2AAA) & mask));
		if (probe_timing_exit)
			programmer_delay(10);
	}
	chip_writeb(flash, 0xF0, bios + ((shifted ? 0x2AAA : 0x5555) & mask));
	if (probe_timing_exit)
		programmer_delay(probe_timing_exit);

	msg_cdbg("%s: id1 0x%02x, id2 0x%02x", __func__, largeid1, largeid2);
	if (!oddparity(id1))
		msg_cdbg(", id1 parity violation");

	/* Read the product ID location again. We should now see normal flash contents. */
	flashcontent1 = chip_readb(flash, bios + (0x00 << shifted));
	flashcontent2 = chip_readb(flash, bios + (0x01 << shifted));

	/* Check if it is a continuation ID, this should be a while loop. */
	if (flashcontent1 == 0x7F) {
		flashcontent1 <<= 8;
		flashcontent1 |= chip_readb(flash, bios + 0x100);
	}
	if (flashcontent2 == 0x7F) {
		flashcontent2 <<= 8;
		flashcontent2 |= chip_readb(flash, bios + 0x101);
	}

	if (largeid1 == flashcontent1)
		msg_cdbg(", id1 is normal flash content");
	if (largeid2 == flashcontent2)
		msg_cdbg(", id2 is normal flash content");

	msg_cdbg("\n");
	if (largeid1 != chip->manufacture_id || largeid2 != chip->model_id)
		return 0;

	return 1;
}

static int erase_sector_jedec_common(struct flashctx *flash, unsigned int page,
				     unsigned int pagesize, unsigned int mask)
{
	chipaddr bios = flash->virtual_memory;
	bool shifted = (flash->chip->feature_bits & FEATURE_ADDR_SHIFTED);
	unsigned int delay_us = 0;

	if(flash->chip->probe_timing != TIMING_ZERO)
		delay_us = 10;

	/*  Issue the Sector Erase command   */
	chip_writeb(flash, 0xAA, bios + ((shifted ? 0x2AAA : 0x5555) & mask));
	programmer_delay(delay_us);
	chip_writeb(flash, 0x55, bios + ((shifted ? 0x5555 : 0x2AAA) & mask));
	programmer_delay(delay_us);
	chip_writeb(flash, 0x80, bios + ((shifted ? 0x2AAA : 0x5555) & mask));
	programmer_delay(delay_us);

	chip_writeb(flash, 0xAA, bios + ((shifted ? 0x2AAA : 0x5555) & mask));
	programmer_delay(delay_us);
	chip_writeb(flash, 0x55, bios + ((shifted ? 0x5555 : 0x2AAA) & mask));
	programmer_delay(delay_us);
	chip_writeb(flash, 0x30, bios + page);
	programmer_delay(delay_us);

	/* wait for Toggle bit ready         */
	toggle_ready_jedec_slow(flash, bios);

	/* FIXME: Check the status register for errors. */
	return 0;
}

static int erase_block_jedec_common(struct flashctx *flash, unsigned int block,
				    unsigned int blocksize, unsigned int mask)
{
	chipaddr bios = flash->virtual_memory;
	bool shifted = (flash->chip->feature_bits & FEATURE_ADDR_SHIFTED);
	unsigned int delay_us = 0;

	if(flash->chip->probe_timing != TIMING_ZERO)
		delay_us = 10;

	/*  Issue the Sector Erase command   */
	chip_writeb(flash, 0xAA, bios + ((shifted ? 0x2AAA : 0x5555) & mask));
	programmer_delay(delay_us);
	chip_writeb(flash, 0x55, bios + ((shifted ? 0x5555 : 0x2AAA) & mask));
	programmer_delay(delay_us);
	chip_writeb(flash, 0x80, bios + ((shifted ? 0x2AAA : 0x5555) & mask));
	programmer_delay(delay_us);

	chip_writeb(flash, 0xAA, bios + ((shifted ? 0x2AAA : 0x5555) & mask));
	programmer_delay(delay_us);
	chip_writeb(flash, 0x55, bios + ((shifted ? 0x5555 : 0x2AAA) & mask));
	programmer_delay(delay_us);
	chip_writeb(flash, 0x50, bios + block);
	programmer_delay(delay_us);

	/* wait for Toggle bit ready         */
	toggle_ready_jedec_slow(flash, bios);

	/* FIXME: Check the status register for errors. */
	return 0;
}

static int erase_chip_jedec_common(struct flashctx *flash, unsigned int mask)
{
	chipaddr bios = flash->virtual_memory;
	bool shifted = (flash->chip->feature_bits & FEATURE_ADDR_SHIFTED);
	unsigned int delay_us = 0;

	if(flash->chip->probe_timing != TIMING_ZERO)
		delay_us = 10;

	/*  Issue the JEDEC Chip Erase command   */
	chip_writeb(flash, 0xAA, bios + ((shifted ? 0x2AAA : 0x5555) & mask));
	programmer_delay(delay_us);
	chip_writeb(flash, 0x55, bios + ((shifted ? 0x5555 : 0x2AAA) & mask));
	programmer_delay(delay_us);
	chip_writeb(flash, 0x80, bios + ((shifted ? 0x2AAA : 0x5555) & mask));
	programmer_delay(delay_us);

	chip_writeb(flash, 0xAA, bios + ((shifted ? 0x2AAA : 0x5555) & mask));
	programmer_delay(delay_us);
	chip_writeb(flash, 0x55, bios + ((shifted ? 0x5555 : 0x2AAA) & mask));
	programmer_delay(delay_us);
	chip_writeb(flash, 0x10, bios + ((shifted ? 0x2AAA : 0x5555) & mask));
	programmer_delay(delay_us);

	toggle_ready_jedec_slow(flash, bios);

	/* FIXME: Check the status register for errors. */
	return 0;
}

static int write_byte_program_jedec_common(const struct flashctx *flash, const uint8_t *src,
					   chipaddr dst, unsigned int mask)
{
	int tried = 0, failed = 0;
	chipaddr bios = flash->virtual_memory;

	/* If the data is 0xFF, don't program it and don't complain. */
	if (*src == 0xFF) {
		return 0;
	}

retry:
	/* Issue JEDEC Byte Program command */
	start_program_jedec_common(flash, mask);

	/* transfer data from source to destination */
	chip_writeb(flash, *src, dst);
	toggle_ready_jedec(flash, bios);

	if (chip_readb(flash, dst) != *src && tried++ < MAX_REFLASH_TRIES) {
		goto retry;
	}

	if (tried >= MAX_REFLASH_TRIES)
		failed = 1;

	return failed;
}

/* chunksize is 1 */
int write_jedec_1(struct flashctx *flash, const uint8_t *src, unsigned int start,
		  unsigned int len)
{
	unsigned int i;
	int failed = 0;
	chipaddr dst = flash->virtual_memory + start;
	chipaddr olddst;
	unsigned int mask;

	mask = getaddrmask(flash->chip);

	olddst = dst;
	for (i = 0; i < len; i++) {
		if (write_byte_program_jedec_common(flash, src, dst, mask))
			failed = 1;
		dst++, src++;
		update_progress(flash, FLASHROM_PROGRESS_WRITE, i + 1, len);
	}
	if (failed)
		msg_cerr(" writing sector at 0x%" PRIxPTR " failed!\n", olddst);

	return failed;
}

static int write_page_write_jedec_common(struct flashctx *flash, const uint8_t *src,
					 unsigned int start, unsigned int page_size)
{
	unsigned int i;
	int tried = 0, failed;
	const uint8_t *s = src;
	chipaddr bios = flash->virtual_memory;
	chipaddr dst = bios + start;
	chipaddr d = dst;
	unsigned int mask;

	mask = getaddrmask(flash->chip);

retry:
	/* Issue JEDEC Start Program command */
	start_program_jedec_common(flash, mask);

	/* transfer data from source to destination */
	for (i = 0; i < page_size; i++) {
		/* If the data is 0xFF, don't program it */
		if (*src != 0xFF)
			chip_writeb(flash, *src, dst);
		dst++;
		src++;
	}

	toggle_ready_jedec(flash, dst - 1);

	dst = d;
	src = s;
	failed = verify_range(flash, src, start, page_size);

	if (failed && tried++ < MAX_REFLASH_TRIES) {
		msg_cerr("retrying.\n");
		goto retry;
	}
	if (failed) {
		msg_cerr(" page 0x%" PRIxPTR " failed!\n", (d - bios) / page_size);
	}
	return failed;
}

/* chunksize is page_size */
/*
 * Write a part of the flash chip.
 * FIXME: Use the chunk code from Michael Karcher instead.
 * This function is a slightly modified copy of spi_write_chunked.
 * Each page is written separately in chunks with a maximum size of chunksize.
 */
int write_jedec(struct flashctx *flash, const uint8_t *buf, unsigned int start,
		int unsigned len)
{
	unsigned int i, starthere, lenhere;
	/* FIXME: page_size is the wrong variable. We need max_writechunk_size
	 * in struct flashctx to do this properly. All chips using
	 * write_jedec have page_size set to max_writechunk_size, so
	 * we're OK for now.
	 */
	unsigned int page_size = flash->chip->page_size;
	unsigned int nwrites = (start + len - 1) / page_size;

	/* Warning: This loop has a very unusual condition and body.
	 * The loop needs to go through each page with at least one affected
	 * byte. The lowest page number is (start / page_size) since that
	 * division rounds down. The highest page number we want is the page
	 * where the last byte of the range lives. That last byte has the
	 * address (start + len - 1), thus the highest page number is
	 * (start + len - 1) / page_size. Since we want to include that last
	 * page as well, the loop condition uses <=.
	 */
	for (i = start / page_size; i <= nwrites; i++) {
		/* Byte position of the first byte in the range in this page. */
		/* starthere is an offset to the base address of the chip. */
		starthere = max(start, i * page_size);
		/* Length of bytes in the range in this page. */
		lenhere = min(start + len, (i + 1) * page_size) - starthere;

		if (write_page_write_jedec_common(flash, buf + starthere - start, starthere, lenhere))
			return 1;
		update_progress(flash, FLASHROM_PROGRESS_WRITE, i + 1, nwrites + 1);
	}

	return 0;
}

/* erase chip with block_erase() prototype */
int erase_chip_block_jedec(struct flashctx *flash, unsigned int addr,
			   unsigned int blocksize)
{
	unsigned int mask;

	mask = getaddrmask(flash->chip);
	if ((addr != 0) || (blocksize != flash->chip->total_size * 1024)) {
		msg_cerr("%s called with incorrect arguments\n",
			__func__);
		return -1;
	}
	return erase_chip_jedec_common(flash, mask);
}

int probe_jedec(struct flashctx *flash)
{
	unsigned int mask;

	mask = getaddrmask(flash->chip);
	return probe_jedec_common(flash, mask);
}

int erase_sector_jedec(struct flashctx *flash, unsigned int page,
		       unsigned int size)
{
	unsigned int mask;

	mask = getaddrmask(flash->chip);
	return erase_sector_jedec_common(flash, page, size, mask);
}

int erase_block_jedec(struct flashctx *flash, unsigned int page,
		      unsigned int size)
{
	unsigned int mask;

	mask = getaddrmask(flash->chip);
	return erase_block_jedec_common(flash, page, size, mask);
}

struct unlockblock {
	unsigned int size;
	unsigned int count;
};

typedef int (*unlockblock_func)(const struct flashctx *flash, chipaddr offset);
static int regspace2_walk_unlockblocks(const struct flashctx *flash, const struct unlockblock *block, unlockblock_func func)
{
	chipaddr off = flash->virtual_registers + 2;
	while (block->count != 0) {
		unsigned int j;
		for (j = 0; j < block->count; j++) {
			if (func(flash, off))
				return -1;
			off += block->size;
		}
		block++;
	}
	return 0;
}

#define REG2_RWLOCK ((1 << 2) | (1 << 0))
#define REG2_LOCKDOWN (1 << 1)
#define REG2_MASK (REG2_RWLOCK | REG2_LOCKDOWN)

static int printlock_regspace2_block(const struct flashctx *flash, chipaddr lockreg)
{
	uint8_t state = chip_readb(flash, lockreg);
	msg_cdbg("Lock status of block at 0x%0*" PRIxPTR " is ", PRIxPTR_WIDTH, lockreg);
	switch (state & REG2_MASK) {
	case 0:
		msg_cdbg("Full Access.\n");
		break;
	case 1:
		msg_cdbg("Write Lock (Default State).\n");
		break;
	case 2:
		msg_cdbg("Locked Open (Full Access, Locked Down).\n");
		break;
	case 3:
		msg_cdbg("Write Lock, Locked Down.\n");
		break;
	case 4:
		msg_cdbg("Read Lock.\n");
		break;
	case 5:
		msg_cdbg("Read/Write Lock.\n");
		break;
	case 6:
		msg_cdbg("Read Lock, Locked Down.\n");
		break;
	case 7:
		msg_cdbg("Read/Write Lock, Locked Down.\n");
		break;
	}
	return 0;
}

static int printlock_regspace2_uniform(struct flashctx *flash, unsigned long block_size)
{
	const unsigned int elems = flash->chip->total_size * 1024 / block_size;
	struct unlockblock blocks[2] = {{.size = block_size, .count = elems}};
	return regspace2_walk_unlockblocks(flash, blocks, &printlock_regspace2_block);
}

int printlock_regspace2_uniform_64k(struct flashctx *flash)
{
	return printlock_regspace2_uniform(flash, 64 * 1024);
}

int printlock_regspace2_block_eraser_0(struct flashctx *flash)
{
	// FIXME: this depends on the eraseblocks not to be filled up completely (i.e. to be null-terminated).
	const struct unlockblock *unlockblocks =
		(const struct unlockblock *)flash->chip->block_erasers[0].eraseblocks;
	return regspace2_walk_unlockblocks(flash, unlockblocks, &printlock_regspace2_block);
}

int printlock_regspace2_block_eraser_1(struct flashctx *flash)
{
	// FIXME: this depends on the eraseblocks not to be filled up completely (i.e. to be null-terminated).
	const struct unlockblock *unlockblocks =
		(const struct unlockblock *)flash->chip->block_erasers[1].eraseblocks;
	return regspace2_walk_unlockblocks(flash, unlockblocks, &printlock_regspace2_block);
}

/* Try to change the lock register at address lockreg from cur to new.
 *
 * - Try to unlock the lock bit if requested and it is currently set (although this is probably futile).
 * - Try to change the read/write bits if requested.
 * - Try to set the lockdown bit if requested.
 * Return an error immediately if any of this fails. */
static int changelock_regspace2_block(const struct flashctx *flash, chipaddr lockreg, uint8_t cur, uint8_t new)
{
	/* Only allow changes to known read/write/lockdown bits */
	if (((cur ^ new) & ~REG2_MASK) != 0) {
		msg_cerr("Invalid lock change from 0x%02x to 0x%02x requested at 0x%0*" PRIxPTR "!\n"
			 "Please report a bug at flashrom@flashrom.org\n",
			 cur, new, PRIxPTR_WIDTH, lockreg);
		return -1;
	}

	/* Exit early if no change (of read/write/lockdown bits) was requested. */
	if (((cur ^ new) & REG2_MASK) == 0) {
		msg_cdbg2("Lock bits at 0x%0*" PRIxPTR " not changed.\n", PRIxPTR_WIDTH, lockreg);
		return 0;
	}

	/* Normally the lockdown bit can not be cleared. Try nevertheless if requested. */
	if ((cur & REG2_LOCKDOWN) && !(new & REG2_LOCKDOWN)) {
		chip_writeb(flash, cur & ~REG2_LOCKDOWN, lockreg);
		cur = chip_readb(flash, lockreg);
		if ((cur & REG2_LOCKDOWN) == REG2_LOCKDOWN) {
			msg_cwarn("Lockdown can't be removed at 0x%0*" PRIxPTR "! New value: 0x%02x.\n",
				  PRIxPTR_WIDTH, lockreg, cur);
			return -1;
		}
	}

	/* Change read and/or write bit */
	if ((cur ^ new) & REG2_RWLOCK) {
		/* Do not lockdown yet. */
		uint8_t wanted = (cur & ~REG2_RWLOCK) | (new & REG2_RWLOCK);
		chip_writeb(flash, wanted, lockreg);
		cur = chip_readb(flash, lockreg);
		if (cur != wanted) {
			msg_cerr("Changing lock bits failed at 0x%0*" PRIxPTR "! New value: 0x%02x.\n",
				 PRIxPTR_WIDTH, lockreg, cur);
			return -1;
		}
		msg_cdbg("Changed lock bits at 0x%0*" PRIxPTR " to 0x%02x.\n",
			 PRIxPTR_WIDTH, lockreg, cur);
	}

	/* Eventually, enable lockdown if requested. */
	if (!(cur & REG2_LOCKDOWN) && (new & REG2_LOCKDOWN)) {
		chip_writeb(flash, new, lockreg);
		cur = chip_readb(flash, lockreg);
		if (cur != new) {
			msg_cerr("Enabling lockdown FAILED at 0x%0*" PRIxPTR "! New value: 0x%02x.\n",
				 PRIxPTR_WIDTH, lockreg, cur);
			return -1;
		}
		msg_cdbg("Enabled lockdown at 0x%0*" PRIxPTR ".\n", PRIxPTR_WIDTH, lockreg);
	}

	return 0;
}

static int unlock_regspace2_block_generic(const struct flashctx *flash, chipaddr lockreg)
{
	uint8_t old = chip_readb(flash, lockreg);
	/* We don't care for the lockdown bit as long as the RW locks are 0 after we're done */
	return changelock_regspace2_block(flash, lockreg, old, old & ~REG2_RWLOCK);
}

static int unlock_regspace2_uniform(struct flashctx *flash, unsigned long block_size)
{
	const unsigned int elems = flash->chip->total_size * 1024 / block_size;
	struct unlockblock blocks[2] = {{.size = block_size, .count = elems}};
	return regspace2_walk_unlockblocks(flash, blocks, &unlock_regspace2_block_generic);
}

int unlock_regspace2_uniform_64k(struct flashctx *flash)
{
	return unlock_regspace2_uniform(flash, 64 * 1024);
}

int unlock_regspace2_uniform_32k(struct flashctx *flash)
{
	return unlock_regspace2_uniform(flash, 32 * 1024);
}

int unlock_regspace2_block_eraser_0(struct flashctx *flash)
{
	// FIXME: this depends on the eraseblocks not to be filled up completely (i.e. to be null-terminated).
	const struct unlockblock *unlockblocks =
		(const struct unlockblock *)flash->chip->block_erasers[0].eraseblocks;
	return regspace2_walk_unlockblocks(flash, unlockblocks, &unlock_regspace2_block_generic);
}

int unlock_regspace2_block_eraser_1(struct flashctx *flash)
{
	// FIXME: this depends on the eraseblocks not to be filled up completely (i.e. to be null-terminated).
	const struct unlockblock *unlockblocks =
		(const struct unlockblock *)flash->chip->block_erasers[1].eraseblocks;
	return regspace2_walk_unlockblocks(flash, unlockblocks, &unlock_regspace2_block_generic);
}