xref: /linux/block/partitions/acorn.c (revision c0c914eca7f251c70facc37dfebeaf176601918d)
1 /*
2  *  linux/fs/partitions/acorn.c
3  *
4  *  Copyright (c) 1996-2000 Russell King.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  *
10  *  Scan ADFS partitions on hard disk drives.  Unfortunately, there
11  *  isn't a standard for partitioning drives on Acorn machines, so
12  *  every single manufacturer of SCSI and IDE cards created their own
13  *  method.
14  */
15 #include <linux/buffer_head.h>
16 #include <linux/adfs_fs.h>
17 
18 #include "check.h"
19 #include "acorn.h"
20 
21 /*
22  * Partition types. (Oh for reusability)
23  */
24 #define PARTITION_RISCIX_MFM	1
25 #define PARTITION_RISCIX_SCSI	2
26 #define PARTITION_LINUX		9
27 
28 #if defined(CONFIG_ACORN_PARTITION_CUMANA) || \
29 	defined(CONFIG_ACORN_PARTITION_ADFS)
30 static struct adfs_discrecord *
31 adfs_partition(struct parsed_partitions *state, char *name, char *data,
32 	       unsigned long first_sector, int slot)
33 {
34 	struct adfs_discrecord *dr;
35 	unsigned int nr_sects;
36 
37 	if (adfs_checkbblk(data))
38 		return NULL;
39 
40 	dr = (struct adfs_discrecord *)(data + 0x1c0);
41 
42 	if (dr->disc_size == 0 && dr->disc_size_high == 0)
43 		return NULL;
44 
45 	nr_sects = (le32_to_cpu(dr->disc_size_high) << 23) |
46 		   (le32_to_cpu(dr->disc_size) >> 9);
47 
48 	if (name) {
49 		strlcat(state->pp_buf, " [", PAGE_SIZE);
50 		strlcat(state->pp_buf, name, PAGE_SIZE);
51 		strlcat(state->pp_buf, "]", PAGE_SIZE);
52 	}
53 	put_partition(state, slot, first_sector, nr_sects);
54 	return dr;
55 }
56 #endif
57 
58 #ifdef CONFIG_ACORN_PARTITION_RISCIX
59 
60 struct riscix_part {
61 	__le32	start;
62 	__le32	length;
63 	__le32	one;
64 	char	name[16];
65 };
66 
67 struct riscix_record {
68 	__le32	magic;
69 #define RISCIX_MAGIC	cpu_to_le32(0x4a657320)
70 	__le32	date;
71 	struct riscix_part part[8];
72 };
73 
74 #if defined(CONFIG_ACORN_PARTITION_CUMANA) || \
75 	defined(CONFIG_ACORN_PARTITION_ADFS)
76 static int riscix_partition(struct parsed_partitions *state,
77 			    unsigned long first_sect, int slot,
78 			    unsigned long nr_sects)
79 {
80 	Sector sect;
81 	struct riscix_record *rr;
82 
83 	rr = read_part_sector(state, first_sect, &sect);
84 	if (!rr)
85 		return -1;
86 
87 	strlcat(state->pp_buf, " [RISCiX]", PAGE_SIZE);
88 
89 
90 	if (rr->magic == RISCIX_MAGIC) {
91 		unsigned long size = nr_sects > 2 ? 2 : nr_sects;
92 		int part;
93 
94 		strlcat(state->pp_buf, " <", PAGE_SIZE);
95 
96 		put_partition(state, slot++, first_sect, size);
97 		for (part = 0; part < 8; part++) {
98 			if (rr->part[part].one &&
99 			    memcmp(rr->part[part].name, "All\0", 4)) {
100 				put_partition(state, slot++,
101 					le32_to_cpu(rr->part[part].start),
102 					le32_to_cpu(rr->part[part].length));
103 				strlcat(state->pp_buf, "(", PAGE_SIZE);
104 				strlcat(state->pp_buf, rr->part[part].name, PAGE_SIZE);
105 				strlcat(state->pp_buf, ")", PAGE_SIZE);
106 			}
107 		}
108 
109 		strlcat(state->pp_buf, " >\n", PAGE_SIZE);
110 	} else {
111 		put_partition(state, slot++, first_sect, nr_sects);
112 	}
113 
114 	put_dev_sector(sect);
115 	return slot;
116 }
117 #endif
118 #endif
119 
120 #define LINUX_NATIVE_MAGIC 0xdeafa1de
121 #define LINUX_SWAP_MAGIC   0xdeafab1e
122 
123 struct linux_part {
124 	__le32 magic;
125 	__le32 start_sect;
126 	__le32 nr_sects;
127 };
128 
129 #if defined(CONFIG_ACORN_PARTITION_CUMANA) || \
130 	defined(CONFIG_ACORN_PARTITION_ADFS)
131 static int linux_partition(struct parsed_partitions *state,
132 			   unsigned long first_sect, int slot,
133 			   unsigned long nr_sects)
134 {
135 	Sector sect;
136 	struct linux_part *linuxp;
137 	unsigned long size = nr_sects > 2 ? 2 : nr_sects;
138 
139 	strlcat(state->pp_buf, " [Linux]", PAGE_SIZE);
140 
141 	put_partition(state, slot++, first_sect, size);
142 
143 	linuxp = read_part_sector(state, first_sect, &sect);
144 	if (!linuxp)
145 		return -1;
146 
147 	strlcat(state->pp_buf, " <", PAGE_SIZE);
148 	while (linuxp->magic == cpu_to_le32(LINUX_NATIVE_MAGIC) ||
149 	       linuxp->magic == cpu_to_le32(LINUX_SWAP_MAGIC)) {
150 		if (slot == state->limit)
151 			break;
152 		put_partition(state, slot++, first_sect +
153 				 le32_to_cpu(linuxp->start_sect),
154 				 le32_to_cpu(linuxp->nr_sects));
155 		linuxp ++;
156 	}
157 	strlcat(state->pp_buf, " >", PAGE_SIZE);
158 
159 	put_dev_sector(sect);
160 	return slot;
161 }
162 #endif
163 
164 #ifdef CONFIG_ACORN_PARTITION_CUMANA
165 int adfspart_check_CUMANA(struct parsed_partitions *state)
166 {
167 	unsigned long first_sector = 0;
168 	unsigned int start_blk = 0;
169 	Sector sect;
170 	unsigned char *data;
171 	char *name = "CUMANA/ADFS";
172 	int first = 1;
173 	int slot = 1;
174 
175 	/*
176 	 * Try Cumana style partitions - sector 6 contains ADFS boot block
177 	 * with pointer to next 'drive'.
178 	 *
179 	 * There are unknowns in this code - is the 'cylinder number' of the
180 	 * next partition relative to the start of this one - I'm assuming
181 	 * it is.
182 	 *
183 	 * Also, which ID did Cumana use?
184 	 *
185 	 * This is totally unfinished, and will require more work to get it
186 	 * going. Hence it is totally untested.
187 	 */
188 	do {
189 		struct adfs_discrecord *dr;
190 		unsigned int nr_sects;
191 
192 		data = read_part_sector(state, start_blk * 2 + 6, &sect);
193 		if (!data)
194 			return -1;
195 
196 		if (slot == state->limit)
197 			break;
198 
199 		dr = adfs_partition(state, name, data, first_sector, slot++);
200 		if (!dr)
201 			break;
202 
203 		name = NULL;
204 
205 		nr_sects = (data[0x1fd] + (data[0x1fe] << 8)) *
206 			   (dr->heads + (dr->lowsector & 0x40 ? 1 : 0)) *
207 			   dr->secspertrack;
208 
209 		if (!nr_sects)
210 			break;
211 
212 		first = 0;
213 		first_sector += nr_sects;
214 		start_blk += nr_sects >> (BLOCK_SIZE_BITS - 9);
215 		nr_sects = 0; /* hmm - should be partition size */
216 
217 		switch (data[0x1fc] & 15) {
218 		case 0: /* No partition / ADFS? */
219 			break;
220 
221 #ifdef CONFIG_ACORN_PARTITION_RISCIX
222 		case PARTITION_RISCIX_SCSI:
223 			/* RISCiX - we don't know how to find the next one. */
224 			slot = riscix_partition(state, first_sector, slot,
225 						nr_sects);
226 			break;
227 #endif
228 
229 		case PARTITION_LINUX:
230 			slot = linux_partition(state, first_sector, slot,
231 					       nr_sects);
232 			break;
233 		}
234 		put_dev_sector(sect);
235 		if (slot == -1)
236 			return -1;
237 	} while (1);
238 	put_dev_sector(sect);
239 	return first ? 0 : 1;
240 }
241 #endif
242 
243 #ifdef CONFIG_ACORN_PARTITION_ADFS
244 /*
245  * Purpose: allocate ADFS partitions.
246  *
247  * Params : hd		- pointer to gendisk structure to store partition info.
248  *	    dev		- device number to access.
249  *
250  * Returns: -1 on error, 0 for no ADFS boot sector, 1 for ok.
251  *
252  * Alloc  : hda  = whole drive
253  *	    hda1 = ADFS partition on first drive.
254  *	    hda2 = non-ADFS partition.
255  */
256 int adfspart_check_ADFS(struct parsed_partitions *state)
257 {
258 	unsigned long start_sect, nr_sects, sectscyl, heads;
259 	Sector sect;
260 	unsigned char *data;
261 	struct adfs_discrecord *dr;
262 	unsigned char id;
263 	int slot = 1;
264 
265 	data = read_part_sector(state, 6, &sect);
266 	if (!data)
267 		return -1;
268 
269 	dr = adfs_partition(state, "ADFS", data, 0, slot++);
270 	if (!dr) {
271 		put_dev_sector(sect);
272     		return 0;
273 	}
274 
275 	heads = dr->heads + ((dr->lowsector >> 6) & 1);
276 	sectscyl = dr->secspertrack * heads;
277 	start_sect = ((data[0x1fe] << 8) + data[0x1fd]) * sectscyl;
278 	id = data[0x1fc] & 15;
279 	put_dev_sector(sect);
280 
281 	/*
282 	 * Work out start of non-adfs partition.
283 	 */
284 	nr_sects = (state->bdev->bd_inode->i_size >> 9) - start_sect;
285 
286 	if (start_sect) {
287 		switch (id) {
288 #ifdef CONFIG_ACORN_PARTITION_RISCIX
289 		case PARTITION_RISCIX_SCSI:
290 		case PARTITION_RISCIX_MFM:
291 			slot = riscix_partition(state, start_sect, slot,
292 						nr_sects);
293 			break;
294 #endif
295 
296 		case PARTITION_LINUX:
297 			slot = linux_partition(state, start_sect, slot,
298 					       nr_sects);
299 			break;
300 		}
301 	}
302 	strlcat(state->pp_buf, "\n", PAGE_SIZE);
303 	return 1;
304 }
305 #endif
306 
307 #ifdef CONFIG_ACORN_PARTITION_ICS
308 
309 struct ics_part {
310 	__le32 start;
311 	__le32 size;
312 };
313 
314 static int adfspart_check_ICSLinux(struct parsed_partitions *state,
315 				   unsigned long block)
316 {
317 	Sector sect;
318 	unsigned char *data = read_part_sector(state, block, &sect);
319 	int result = 0;
320 
321 	if (data) {
322 		if (memcmp(data, "LinuxPart", 9) == 0)
323 			result = 1;
324 		put_dev_sector(sect);
325 	}
326 
327 	return result;
328 }
329 
330 /*
331  * Check for a valid ICS partition using the checksum.
332  */
333 static inline int valid_ics_sector(const unsigned char *data)
334 {
335 	unsigned long sum;
336 	int i;
337 
338 	for (i = 0, sum = 0x50617274; i < 508; i++)
339 		sum += data[i];
340 
341 	sum -= le32_to_cpu(*(__le32 *)(&data[508]));
342 
343 	return sum == 0;
344 }
345 
346 /*
347  * Purpose: allocate ICS partitions.
348  * Params : hd		- pointer to gendisk structure to store partition info.
349  *	    dev		- device number to access.
350  * Returns: -1 on error, 0 for no ICS table, 1 for partitions ok.
351  * Alloc  : hda  = whole drive
352  *	    hda1 = ADFS partition 0 on first drive.
353  *	    hda2 = ADFS partition 1 on first drive.
354  *		..etc..
355  */
356 int adfspart_check_ICS(struct parsed_partitions *state)
357 {
358 	const unsigned char *data;
359 	const struct ics_part *p;
360 	int slot;
361 	Sector sect;
362 
363 	/*
364 	 * Try ICS style partitions - sector 0 contains partition info.
365 	 */
366 	data = read_part_sector(state, 0, &sect);
367 	if (!data)
368 	    	return -1;
369 
370 	if (!valid_ics_sector(data)) {
371 	    	put_dev_sector(sect);
372 		return 0;
373 	}
374 
375 	strlcat(state->pp_buf, " [ICS]", PAGE_SIZE);
376 
377 	for (slot = 1, p = (const struct ics_part *)data; p->size; p++) {
378 		u32 start = le32_to_cpu(p->start);
379 		s32 size = le32_to_cpu(p->size); /* yes, it's signed. */
380 
381 		if (slot == state->limit)
382 			break;
383 
384 		/*
385 		 * Negative sizes tell the RISC OS ICS driver to ignore
386 		 * this partition - in effect it says that this does not
387 		 * contain an ADFS filesystem.
388 		 */
389 		if (size < 0) {
390 			size = -size;
391 
392 			/*
393 			 * Our own extension - We use the first sector
394 			 * of the partition to identify what type this
395 			 * partition is.  We must not make this visible
396 			 * to the filesystem.
397 			 */
398 			if (size > 1 && adfspart_check_ICSLinux(state, start)) {
399 				start += 1;
400 				size -= 1;
401 			}
402 		}
403 
404 		if (size)
405 			put_partition(state, slot++, start, size);
406 	}
407 
408 	put_dev_sector(sect);
409 	strlcat(state->pp_buf, "\n", PAGE_SIZE);
410 	return 1;
411 }
412 #endif
413 
414 #ifdef CONFIG_ACORN_PARTITION_POWERTEC
415 struct ptec_part {
416 	__le32 unused1;
417 	__le32 unused2;
418 	__le32 start;
419 	__le32 size;
420 	__le32 unused5;
421 	char type[8];
422 };
423 
424 static inline int valid_ptec_sector(const unsigned char *data)
425 {
426 	unsigned char checksum = 0x2a;
427 	int i;
428 
429 	/*
430 	 * If it looks like a PC/BIOS partition, then it
431 	 * probably isn't PowerTec.
432 	 */
433 	if (data[510] == 0x55 && data[511] == 0xaa)
434 		return 0;
435 
436 	for (i = 0; i < 511; i++)
437 		checksum += data[i];
438 
439 	return checksum == data[511];
440 }
441 
442 /*
443  * Purpose: allocate ICS partitions.
444  * Params : hd		- pointer to gendisk structure to store partition info.
445  *	    dev		- device number to access.
446  * Returns: -1 on error, 0 for no ICS table, 1 for partitions ok.
447  * Alloc  : hda  = whole drive
448  *	    hda1 = ADFS partition 0 on first drive.
449  *	    hda2 = ADFS partition 1 on first drive.
450  *		..etc..
451  */
452 int adfspart_check_POWERTEC(struct parsed_partitions *state)
453 {
454 	Sector sect;
455 	const unsigned char *data;
456 	const struct ptec_part *p;
457 	int slot = 1;
458 	int i;
459 
460 	data = read_part_sector(state, 0, &sect);
461 	if (!data)
462 		return -1;
463 
464 	if (!valid_ptec_sector(data)) {
465 		put_dev_sector(sect);
466 		return 0;
467 	}
468 
469 	strlcat(state->pp_buf, " [POWERTEC]", PAGE_SIZE);
470 
471 	for (i = 0, p = (const struct ptec_part *)data; i < 12; i++, p++) {
472 		u32 start = le32_to_cpu(p->start);
473 		u32 size = le32_to_cpu(p->size);
474 
475 		if (size)
476 			put_partition(state, slot++, start, size);
477 	}
478 
479 	put_dev_sector(sect);
480 	strlcat(state->pp_buf, "\n", PAGE_SIZE);
481 	return 1;
482 }
483 #endif
484 
485 #ifdef CONFIG_ACORN_PARTITION_EESOX
486 struct eesox_part {
487 	char	magic[6];
488 	char	name[10];
489 	__le32	start;
490 	__le32	unused6;
491 	__le32	unused7;
492 	__le32	unused8;
493 };
494 
495 /*
496  * Guess who created this format?
497  */
498 static const char eesox_name[] = {
499 	'N', 'e', 'i', 'l', ' ',
500 	'C', 'r', 'i', 't', 'c', 'h', 'e', 'l', 'l', ' ', ' '
501 };
502 
503 /*
504  * EESOX SCSI partition format.
505  *
506  * This is a goddamned awful partition format.  We don't seem to store
507  * the size of the partition in this table, only the start addresses.
508  *
509  * There are two possibilities where the size comes from:
510  *  1. The individual ADFS boot block entries that are placed on the disk.
511  *  2. The start address of the next entry.
512  */
513 int adfspart_check_EESOX(struct parsed_partitions *state)
514 {
515 	Sector sect;
516 	const unsigned char *data;
517 	unsigned char buffer[256];
518 	struct eesox_part *p;
519 	sector_t start = 0;
520 	int i, slot = 1;
521 
522 	data = read_part_sector(state, 7, &sect);
523 	if (!data)
524 		return -1;
525 
526 	/*
527 	 * "Decrypt" the partition table.  God knows why...
528 	 */
529 	for (i = 0; i < 256; i++)
530 		buffer[i] = data[i] ^ eesox_name[i & 15];
531 
532 	put_dev_sector(sect);
533 
534 	for (i = 0, p = (struct eesox_part *)buffer; i < 8; i++, p++) {
535 		sector_t next;
536 
537 		if (memcmp(p->magic, "Eesox", 6))
538 			break;
539 
540 		next = le32_to_cpu(p->start);
541 		if (i)
542 			put_partition(state, slot++, start, next - start);
543 		start = next;
544 	}
545 
546 	if (i != 0) {
547 		sector_t size;
548 
549 		size = get_capacity(state->bdev->bd_disk);
550 		put_partition(state, slot++, start, size - start);
551 		strlcat(state->pp_buf, "\n", PAGE_SIZE);
552 	}
553 
554 	return i ? 1 : 0;
555 }
556 #endif
557