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)
30static struct adfs_discrecord *
31adfs_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
60struct riscix_part {
61	__le32	start;
62	__le32	length;
63	__le32	one;
64	char	name[16];
65};
66
67struct 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)
76static 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
123struct 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)
131static 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
165int 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 */
256int 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
309struct ics_part {
310	__le32 start;
311	__le32 size;
312};
313
314static 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 */
333static 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 */
356int 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
415struct ptec_part {
416	__le32 unused1;
417	__le32 unused2;
418	__le32 start;
419	__le32 size;
420	__le32 unused5;
421	char type[8];
422};
423
424static 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 */
452int 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
486struct 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 */
498static 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 */
513int 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