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
|
/*
* Linux driver for SSFDC Flash Translation Layer (Read only)
* © 2005 Eptar srl
* Author: Claudio Lanconelli <lanconelli.claudio@eptar.com>
*
* Based on NTFL and MTDBLOCK_RO drivers
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/hdreg.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/blktrans.h>
struct ssfdcr_record {
struct mtd_blktrans_dev mbd;
int usecount;
unsigned char heads;
unsigned char sectors;
unsigned short cylinders;
int cis_block; /* block n. containing CIS/IDI */
int erase_size; /* phys_block_size */
unsigned short *logic_block_map; /* all zones (max 8192 phys blocks on
the 128MiB) */
int map_len; /* n. phys_blocks on the card */
};
#define SSFDCR_MAJOR 257
#define SSFDCR_PARTN_BITS 3
#define SECTOR_SIZE 512
#define SECTOR_SHIFT 9
#define OOB_SIZE 16
#define MAX_LOGIC_BLK_PER_ZONE 1000
#define MAX_PHYS_BLK_PER_ZONE 1024
#define KiB(x) ( (x) * 1024L )
#define MiB(x) ( KiB(x) * 1024L )
/** CHS Table
1MiB 2MiB 4MiB 8MiB 16MiB 32MiB 64MiB 128MiB
NCylinder 125 125 250 250 500 500 500 500
NHead 4 4 4 4 4 8 8 16
NSector 4 8 8 16 16 16 32 32
SumSector 2,000 4,000 8,000 16,000 32,000 64,000 128,000 256,000
SectorSize 512 512 512 512 512 512 512 512
**/
typedef struct {
unsigned long size;
unsigned short cyl;
unsigned char head;
unsigned char sec;
} chs_entry_t;
/* Must be ordered by size */
static const chs_entry_t chs_table[] = {
{ MiB( 1), 125, 4, 4 },
{ MiB( 2), 125, 4, 8 },
{ MiB( 4), 250, 4, 8 },
{ MiB( 8), 250, 4, 16 },
{ MiB( 16), 500, 4, 16 },
{ MiB( 32), 500, 8, 16 },
{ MiB( 64), 500, 8, 32 },
{ MiB(128), 500, 16, 32 },
{ 0 },
};
static int get_chs(unsigned long size, unsigned short *cyl, unsigned char *head,
unsigned char *sec)
{
int k;
int found = 0;
k = 0;
while (chs_table[k].size > 0 && size > chs_table[k].size)
k++;
if (chs_table[k].size > 0) {
if (cyl)
*cyl = chs_table[k].cyl;
if (head)
*head = chs_table[k].head;
if (sec)
*sec = chs_table[k].sec;
found = 1;
}
return found;
}
/* These bytes are the signature for the CIS/IDI sector */
static const uint8_t cis_numbers[] = {
0x01, 0x03, 0xD9, 0x01, 0xFF, 0x18, 0x02, 0xDF, 0x01, 0x20
};
/* Read and check for a valid CIS sector */
static int get_valid_cis_sector(struct mtd_info *mtd)
{
int ret, k, cis_sector;
size_t retlen;
loff_t offset;
uint8_t *sect_buf;
cis_sector = -1;
sect_buf = kmalloc(SECTOR_SIZE, GFP_KERNEL);
if (!sect_buf)
goto out;
/*
* Look for CIS/IDI sector on the first GOOD block (give up after 4 bad
* blocks). If the first good block doesn't contain CIS number the flash
* is not SSFDC formatted
*/
for (k = 0, offset = 0; k < 4; k++, offset += mtd->erasesize) {
if (mtd_block_isbad(mtd, offset)) {
ret = mtd_read(mtd, offset, SECTOR_SIZE, &retlen,
sect_buf);
/* CIS pattern match on the sector buffer */
if (ret < 0 || retlen != SECTOR_SIZE) {
printk(KERN_WARNING
"SSFDC_RO:can't read CIS/IDI sector\n");
} else if (!memcmp(sect_buf, cis_numbers,
sizeof(cis_numbers))) {
/* Found */
cis_sector = (int)(offset >> SECTOR_SHIFT);
} else {
pr_debug("SSFDC_RO: CIS/IDI sector not found"
" on %s (mtd%d)\n", mtd->name,
mtd->index);
}
break;
}
}
kfree(sect_buf);
out:
return cis_sector;
}
/* Read physical sector (wrapper to MTD_READ) */
static int read_physical_sector(struct mtd_info *mtd, uint8_t *sect_buf,
int sect_no)
{
int ret;
size_t retlen;
loff_t offset = (loff_t)sect_no << SECTOR_SHIFT;
ret = mtd_read(mtd, offset, SECTOR_SIZE, &retlen, sect_buf);
if (ret < 0 || retlen != SECTOR_SIZE)
return -1;
return 0;
}
/* Read redundancy area (wrapper to MTD_READ_OOB */
static int read_raw_oob(struct mtd_info *mtd, loff_t offs, uint8_t *buf)
{
struct mtd_oob_ops ops;
int ret;
ops.mode = MTD_OPS_RAW;
ops.ooboffs = 0;
ops.ooblen = OOB_SIZE;
ops.oobbuf = buf;
ops.datbuf = NULL;
ret = mtd_read_oob(mtd, offs, &ops);
if (ret < 0 || ops.oobretlen != OOB_SIZE)
return -1;
return 0;
}
/* Parity calculator on a word of n bit size */
static int get_parity(int number, int size)
{
int k;
int parity;
parity = 1;
for (k = 0; k < size; k++) {
parity += (number >> k);
parity &= 1;
}
return parity;
}
/* Read and validate the logical block address field stored in the OOB */
static int get_logical_address(uint8_t *oob_buf)
{
int block_address, parity;
int offset[2] = {6, 11}; /* offset of the 2 address fields within OOB */
int j;
int ok = 0;
/*
* Look for the first valid logical address
* Valid address has fixed pattern on most significant bits and
* parity check
*/
for (j = 0; j < ARRAY_SIZE(offset); j++) {
block_address = ((int)oob_buf[offset[j]] << 8) |
oob_buf[offset[j]+1];
/* Check for the signature bits in the address field (MSBits) */
if ((block_address & ~0x7FF) == 0x1000) {
parity = block_address & 0x01;
block_address &= 0x7FF;
block_address >>= 1;
if (get_parity(block_address, 10) != parity) {
pr_debug("SSFDC_RO: logical address field%d"
"parity error(0x%04X)\n", j+1,
block_address);
} else {
ok = 1;
break;
}
}
}
if (!ok)
block_address = -2;
pr_debug("SSFDC_RO: get_logical_address() %d\n",
block_address);
return block_address;
}
/* Build the logic block map */
static int build_logical_block_map(struct ssfdcr_record *ssfdc)
{
unsigned long offset;
uint8_t oob_buf[OOB_SIZE];
int ret, block_address, phys_block;
struct mtd_info *mtd = ssfdc->mbd.mtd;
pr_debug("SSFDC_RO: build_block_map() nblks=%d (%luK)\n",
ssfdc->map_len,
(unsigned long)ssfdc->map_len * ssfdc->erase_size / 1024);
/* Scan every physical block, skip CIS block */
for (phys_block = ssfdc->cis_block + 1; phys_block < ssfdc->map_len;
phys_block++) {
offset = (unsigned long
|