aboutsummaryrefslogtreecommitdiffstats
path: root/fs/partitions/acorn.c
blob: a97b477ac0fc38b4e691f6c980b06cc6d921e05a (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
/*
 *  linux/fs/partitions/acorn.c
 *
 *  Copyright (c) 1996-2000 Russell King.
 *
 * 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.
 *
 *  Scan ADFS partitions on hard disk drives.  Unfortunately, there
 *  isn't a standard for partitioning drives on Acorn machines, so
 *  every single manufacturer of SCSI and IDE cards created their own
 *  method.
 */
#include <linux/buffer_head.h>
#include <linux/adfs_fs.h>

#include "check.h"
#include "acorn.h"

/*
 * Partition types. (Oh for reusability)
 */
#define PARTITION_RISCIX_MFM	1
#define PARTITION_RISCIX_SCSI	2
#define PARTITION_LINUX		9

#if defined(CONFIG_ACORN_PARTITION_CUMANA) || \
	defined(CONFIG_ACORN_PARTITION_ADFS)
static struct adfs_discrecord *
adfs_partition(struct parsed_partitions *state, char *name, char *data,
	       unsigned long first_sector, int slot)
{
	struct adfs_discrecord *dr;
	unsigned int nr_sects;

	if (adfs_checkbblk(data))
		return NULL;

	dr = (struct adfs_discrecord *)(data + 0x1c0);

	if (dr->disc_size == 0 && dr->disc_size_high == 0)
		return NULL;

	nr_sects = (le32_to_cpu(dr->disc_size_high) << 23) |
		   (le32_to_cpu(dr->disc_size) >> 9);

	if (name)
		printk(" [%s]", name);
	put_partition(state, slot, first_sector, nr_sects);
	return dr;
}
#endif

#ifdef CONFIG_ACORN_PARTITION_RISCIX

struct riscix_part {
	__le32	start;
	__le32	length;
	__le32	one;
	char	name[16];
};

struct riscix_record {
	__le32	magic;
#define RISCIX_MAGIC	cpu_to_le32(0x4a657320)
	__le32	date;
	struct riscix_part part[8];
};

#if defined(CONFIG_ACORN_PARTITION_CUMANA) || \
	defined(CONFIG_ACORN_PARTITION_ADFS)
static int
riscix_partition(struct parsed_partitions *state, struct block_device *bdev,
		unsigned long first_sect, int slot, unsigned long nr_sects)
{
	Sector sect;
	struct riscix_record *rr;
	
	rr = (struct riscix_record *)read_dev_sector(bdev, first_sect, &sect);
	if (!rr)
		return -1;

	printk(" [RISCiX]");


	if (rr->magic == RISCIX_MAGIC) {
		unsigned long size = nr_sects > 2 ? 2 : nr_sects;
		int part;

		printk(" <");

		put_partition(state, slot++, first_sect, size);
		for (part = 0; part < 8; part++) {
			if (rr->part[part].one &&
			    memcmp(rr->part[part].name, "All\0", 4)) {
				put_partition(state, slot++,
					le32_to_cpu(rr->part[part].start),
					le32_to_cpu(rr->part[part].length));
				printk("(%s)", rr->part[part].name);
			}
		}

		printk(" >\n");
	} else {
		put_partition(state, slot++, first_sect, nr_sects);
	}

	put_dev_sector(sect);
	return slot;
}
#endif
#endif

#define LINUX_NATIVE_MAGIC 0xdeafa1de
#define LINUX_SWAP_MAGIC   0xdeafab1e

struct linux_part {
	__le32 magic;
	__le32 start_sect;
	__le32 nr_sects;
};

#if defined(CONFIG_ACORN_PARTITION_CUMANA) || \
	defined(CONFIG_ACORN_PARTITION_ADFS)
static int
linux_partition(struct parsed_partitions *state, struct block_device *bdev,
		unsigned long first_sect, int slot, unsigned long nr_sects)
{
	Sector sect;
	struct linux_part *linuxp;
	unsigned long size = nr_sects > 2 ? 2 : nr_sects;

	printk(" [Linux]");

	put_partition(state, slot++, first_sect, size);

	linuxp = (struct linux_part *)read_dev_sector(bdev, first_sect, &sect);
	if (!linuxp)
		return -1;

	printk(" <");
	while (linuxp->magic == cpu_to_le32(LINUX_NATIVE_MAGIC) ||
	       linuxp->magic == cpu_to_le32(LINUX_SWAP_MAGIC)) {
		if (slot == state->limit)
			break;
		put_partition(state, slot++, first_sect +
				 le32_to_cpu(linuxp->start_sect),
				 le32_to_cpu(linuxp->nr_sects));
		linuxp ++;
	}
	printk(" >");

	put_dev_sector(sect);
	return slot;
}
#endif

#ifdef CONFIG_ACORN_PARTITION_CUMANA
int
adfspart_check_CUMANA(struct parsed_partitions *state, struct block_device *bdev)
{
	unsigned long first_sector = 0;
	unsigned int start_blk = 0;
	Sector sect;
	unsigned char *data;
	char *name = "CUMANA/ADFS";
	int first = 1;
	int slot = 1;

	/*
	 * Try Cumana style partitions - sector 6 contains ADFS boot block
	 * with pointer to next 'drive'.
	 *
	 * There are unknowns in this code - is the 'cylinder number' of the
	 * next partition relative to the start of this one - I'm assuming
	 * it is.
	 *
	 * Also, which ID did Cumana use?
	 *
	 * This is totally unfinished, and will require more work to get it
	 * going. Hence it is totally untested.
	 */
	do {
		struct adfs_discrecord *dr;
		unsigned int nr_sects;

		data = read_dev_sector(bdev, start_blk * 2 + 6, &sect);
		if (!data)
			return -1;

		if (slot == state->limit)
			break;

		dr = adfs_partition(state, name, data, first_sector, slot++);
		if (!dr)
			break;

		name = NULL;

		nr_sects = (data[0x1fd] + (data[0x1fe] << 8)) *
			   (dr->heads + (dr->lowsector & 0x40 ? 1 : 0)) *
			   dr->secspertrack;

		if (!nr_sects)
			break;

		first = 0;
		first_sector += nr_sects;
		start_blk += nr_sects >> (BLOCK_SIZE_BITS - 9);
		nr_sects = 0; /* hmm - should be partition size */

		switch (data[0x1fc] & 15) {
		case 0: /* No partition / ADFS? */
			break;

#ifdef CONFIG_ACORN_PARTITION_RISCIX
		case PARTITION_RISCIX_SCSI:
			/* RISCiX - we don't know how to find the next one. */
			slot = riscix_partition(state, bdev, first_sector,
						 slot, nr_sects);
			break;
#endif

		case PARTITION_LINUX:
			slot = linux_partition(state, bdev, first_sector,
						slot, nr_sects);
			break;
		}
		put_dev_sector(sect);
		if (slot == -1)
			return -1;
	} while (1);
	put_dev_sector(sect);
	return first ? 0 : 1;
}
#endif

#ifdef CONFIG_ACORN_PARTITION_ADFS
/*
 * Purpose: allocate ADFS partitions.
 *
 * Params : hd		- pointer to gendisk structure to store partition info.
 *	    dev		- device number to access.
 *
 * Returns: -1 on error, 0 for no ADFS boot sector, 1 for ok.
 *
 * Alloc  : hda  = whole drive
 *	    hda1 = ADFS partition on first drive.
 *	    hda2 = non-ADFS partition.
 */
int
adfspart_check_ADFS(struct parsed_partitions *state, struct block_device *bdev)
{
	unsigned long start_sect, nr_sects, sectscyl, heads;
	Sector sect;
	unsigned char *data;
	struct adfs_discrecord *dr;
	unsigned char id;
	int slot = 1;

	data = read_dev_sector(bdev, 6, &sect);
	if (!data)
		return -1;

	dr = adfs_partition(state, "ADFS", data, 0, slot++);
	if (!dr) {
		put_dev_sector(sect);
    		return 0;
	}

	heads = dr->heads + ((dr->lowsector >> 6) & 1);
	sectscyl = dr->secspertrack * heads;
	start_sect = ((data[0x1fe] << 8) + data[0x1fd]) * sectscyl;
	id = data[0x1fc] & 15;
	put_dev_sector(sect);

	/*
	 * Work out start of non-adfs partition.
	 */
	nr_sects = (bdev->bd_inode->i_size >> 9) - start_sect;

	if (start_sect) {
		switch (id) {
#ifdef CONFIG_ACORN_PARTITION_RISCIX
		case PARTITION_RISCIX_SCSI:
		case PARTITION_RISCIX_MFM:
			slot = riscix_partition(state, bdev, start_sect,
						 slot, nr_sects);
			break;
#endif

		case PARTITION_LINUX:
			slot = linux_partition(state, bdev, start_sect,
						slot, nr_sects);
			break;
		}
	}
	printk("\n");
	return 1;
}
#endif

#ifdef CONFIG_ACORN_PARTITION_ICS

struct ics_part {
	__le32 start;
	__le32 size;
};

static int adfspart_check_ICSLinux(struct block_device *bdev, unsigned long block)
{
	Sector sect;
	unsigned char *data = read_dev_sector(bdev, block, &sect);
	int result = 0;

	if (data) {
		if (memcmp(data, "LinuxPart", 9) == 0)
			result = 1;
		put_dev_sector(sect);
	}

	return result;
}

/*
 * Check for a valid ICS partition using the checksum.
 */
static inline int valid_ics_sector(const unsigned char *data)
{
	unsigned long sum;
	int i;

	for (i = 0, sum = 0x50617274; i < 508; i++)
		sum += data[i];

	sum -= le32_to_cpu(*(__le32 *)(&data[508]));

	return sum == 0;
}

/*
 * Purpose: allocate ICS partitions.
 * Params : hd		- pointer to gendisk structure to store partition info.
 *	    dev		- device number to access.
 * Returns: -1 on error, 0 for no ICS table, 1 for partitions ok.
 * Alloc  : hda  = whole drive
 *	    hda1 = ADFS partition 0 on first drive.
 *	    hda2 = ADFS partition 1 on first drive.
 *		..etc..
 */
int
adfspart_check_ICS(struct parsed_partitions *state, struct block_device *bdev)
{
	const unsigned char *data;
	const struct ics_part *p;
	int slot;
	Sector sect;

	/*
	 * Try ICS style partitions - sector 0 contains partition info.
	 */
	data = read_dev_sector(bdev, 0, &sect);
	if (!data)
	    	return -1;

	if (!valid_ics_sector(data)) {
	    	put_dev_sector(sect);
		return 0;
	}

	printk(" [ICS]");

	for (slot = 1, p = (const struct ics_part *)data; p->size; p++) {
		u32 start = le32_to_cpu(p->start);
		s32 size = le32_to_cpu(p->size); /* yes, it's signed. */

		if (slot == state->limit)
			break;

		/*
		 * Negative sizes tell the RISC OS ICS driver to ignore
		 * this partition - in effect it says that this does not
		 * contain an ADFS filesystem.
		 */
		if (size < 0) {
			size = -size;

			/*
			 * Our own extension - We use the first sector
			 * of the partition to identify what type this
			 * partition is.  We must not make this visible
			 * to the filesystem.
			 */
			if (size > 1 && adfspart_check_ICSLinux(bdev, start)) {
				start += 1;
				size -= 1;
			}
		}

		if (size)
			put_partition(state, slot++, start, size);
	}

	put_dev_sector(sect);
	printk("\n");
	return 1;
}
#endif

#ifdef CONFIG_ACORN_PARTITION_POWERTEC
struct ptec_part {
	__le32 unused1;
	__le32 unused2;
	__le32 start;
	__le32 size;
	__le32 unused5;
	char type[8];
};

static inline int valid_ptec_sector(const unsigned char *data)
{
	unsigned char checksum = 0x2a;
	int i;

	/*
	 * If it looks like a PC/BIOS partition, then it
	 * probably isn't PowerTec.
	 */
	if (data[510] == 0x55 && data[511] == 0xaa)
		return 0;

	for (i = 0; i < 511; i++)
		checksum += data[i];

	return checksum == data[511];
}

/*
 * Purpose: allocate ICS partitions.
 * Params : hd		- pointer to gendisk structure to store partition info.
 *	    dev		- device number to access.
 * Returns: -1 on error, 0 for no ICS table, 1 for partitions ok.
 * Alloc  : hda  = whole drive
 *	    hda1 = ADFS partition 0 on first drive.
 *	    hda2 = ADFS partition 1 on first drive.
 *		..etc..
 */
int
adfspart_check_POWERTEC(struct parsed_partitions *state, struct block_device *bdev)
{
	Sector sect;
	const unsigned char *data;
	const struct ptec_part *p;
	int slot = 1;
	int i;

	data = read_dev_sector(bdev, 0, &sect);
	if (!data)
		return -1;

	if (!valid_ptec_sector(data)) {
		put_dev_sector(sect);
		return 0;
	}

	printk(" [POWERTEC]");

	for (i = 0, p = (const struct ptec_part *)data; i < 12; i++, p++) {
		u32 start = le32_to_cpu(p->start);
		u32 size = le32_to_cpu(p->size);

		if (size)
			put_partition(state, slot++, start, size);
	}

	put_dev_sector(sect);
	printk("\n");
	return 1;
}
#endif

#ifdef CONFIG_ACORN_PARTITION_EESOX
struct eesox_part {
	char	magic[6];
	char	name[10];
	__le32	start;
	__le32	unused6;
	__le32	unused7;
	__le32	unused8;
};

/*
 * Guess who created this format?
 */
static const char eesox_name[] = {
	'N', 'e', 'i', 'l', ' ',
	'C', 'r', 'i', 't', 'c', 'h', 'e', 'l', 'l', ' ', ' '
};

/*
 * EESOX SCSI partition format.
 *
 * This is a goddamned awful partition format.  We don't seem to store
 * the size of the partition in this table, only the start addresses.
 *
 * There are two possibilities where the size comes from:
 *  1. The individual ADFS boot block entries that are placed on the disk.
 *  2. The start address of the next entry.
 */
int
adfspart_check_EESOX(struct parsed_partitions *state, struct block_device *bdev)
{
	Sector sect;
	const unsigned char *data;
	unsigned char buffer[256];
	struct eesox_part *p;
	sector_t start = 0;
	int i, slot = 1;

	data = read_dev_sector(bdev, 7, &sect);
	if (!data)
		return -1;

	/*
	 * "Decrypt" the partition table.  God knows why...
	 */
	for (i = 0; i < 256; i++)
		buffer[i] = data[i] ^ eesox_name[i & 15];

	put_dev_sector(sect);

	for (i = 0, p = (struct eesox_part *)buffer; i < 8; i++, p++) {
		sector_t next;

		if (memcmp(p->magic, "Eesox", 6))
			break;

		next = le32_to_cpu(p->start);
		if (i)
			put_partition(state, slot++, start, next - start);
		start = next;
	}

	if (i != 0) {
		sector_t size;

		size = get_capacity(bdev->bd_disk);
		put_partition(state, slot++, start, size - start);
		printk("\n");
	}

	return i ? 1 : 0;
}
#endif