1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (c) 1996-2000 Russell King.
4 *
5 * Scan ADFS partitions on hard disk drives. Unfortunately, there
6 * isn't a standard for partitioning drives on Acorn machines, so
7 * every single manufacturer of SCSI and IDE cards created their own
8 * method.
9 */
10 #include <linux/buffer_head.h>
11 #include <linux/adfs_fs.h>
12
13 #include "check.h"
14
15 /*
16 * Partition types. (Oh for reusability)
17 */
18 #define PARTITION_RISCIX_MFM 1
19 #define PARTITION_RISCIX_SCSI 2
20 #define PARTITION_LINUX 9
21
22 #if defined(CONFIG_ACORN_PARTITION_CUMANA) || \
23 defined(CONFIG_ACORN_PARTITION_ADFS)
24 static struct adfs_discrecord *
adfs_partition(struct parsed_partitions * state,char * name,char * data,unsigned long first_sector,int slot)25 adfs_partition(struct parsed_partitions *state, char *name, char *data,
26 unsigned long first_sector, int slot)
27 {
28 struct adfs_discrecord *dr;
29 unsigned int nr_sects;
30
31 if (adfs_checkbblk(data))
32 return NULL;
33
34 dr = (struct adfs_discrecord *)(data + 0x1c0);
35
36 if (dr->disc_size == 0 && dr->disc_size_high == 0)
37 return NULL;
38
39 nr_sects = (le32_to_cpu(dr->disc_size_high) << 23) |
40 (le32_to_cpu(dr->disc_size) >> 9);
41
42 if (name) {
43 strlcat(state->pp_buf, " [", PAGE_SIZE);
44 strlcat(state->pp_buf, name, PAGE_SIZE);
45 strlcat(state->pp_buf, "]", PAGE_SIZE);
46 }
47 put_partition(state, slot, first_sector, nr_sects);
48 return dr;
49 }
50 #endif
51
52 #ifdef CONFIG_ACORN_PARTITION_RISCIX
53
54 struct riscix_part {
55 __le32 start;
56 __le32 length;
57 __le32 one;
58 char name[16];
59 };
60
61 struct riscix_record {
62 __le32 magic;
63 #define RISCIX_MAGIC cpu_to_le32(0x4a657320)
64 __le32 date;
65 struct riscix_part part[8];
66 };
67
68 #if defined(CONFIG_ACORN_PARTITION_CUMANA) || \
69 defined(CONFIG_ACORN_PARTITION_ADFS)
riscix_partition(struct parsed_partitions * state,unsigned long first_sect,int slot,unsigned long nr_sects)70 static int riscix_partition(struct parsed_partitions *state,
71 unsigned long first_sect, int slot,
72 unsigned long nr_sects)
73 {
74 Sector sect;
75 struct riscix_record *rr;
76
77 rr = read_part_sector(state, first_sect, §);
78 if (!rr)
79 return -1;
80
81 strlcat(state->pp_buf, " [RISCiX]", PAGE_SIZE);
82
83
84 if (rr->magic == RISCIX_MAGIC) {
85 unsigned long size = nr_sects > 2 ? 2 : nr_sects;
86 int part;
87
88 strlcat(state->pp_buf, " <", PAGE_SIZE);
89
90 put_partition(state, slot++, first_sect, size);
91 for (part = 0; part < 8; part++) {
92 if (rr->part[part].one &&
93 memcmp(rr->part[part].name, "All\0", 4)) {
94 put_partition(state, slot++,
95 le32_to_cpu(rr->part[part].start),
96 le32_to_cpu(rr->part[part].length));
97 strlcat(state->pp_buf, "(", PAGE_SIZE);
98 strlcat(state->pp_buf, rr->part[part].name, PAGE_SIZE);
99 strlcat(state->pp_buf, ")", PAGE_SIZE);
100 }
101 }
102
103 strlcat(state->pp_buf, " >\n", PAGE_SIZE);
104 } else {
105 put_partition(state, slot++, first_sect, nr_sects);
106 }
107
108 put_dev_sector(sect);
109 return slot;
110 }
111 #endif
112 #endif
113
114 #define LINUX_NATIVE_MAGIC 0xdeafa1de
115 #define LINUX_SWAP_MAGIC 0xdeafab1e
116
117 struct linux_part {
118 __le32 magic;
119 __le32 start_sect;
120 __le32 nr_sects;
121 };
122
123 #if defined(CONFIG_ACORN_PARTITION_CUMANA) || \
124 defined(CONFIG_ACORN_PARTITION_ADFS)
linux_partition(struct parsed_partitions * state,unsigned long first_sect,int slot,unsigned long nr_sects)125 static int linux_partition(struct parsed_partitions *state,
126 unsigned long first_sect, int slot,
127 unsigned long nr_sects)
128 {
129 Sector sect;
130 struct linux_part *linuxp;
131 unsigned long size = nr_sects > 2 ? 2 : nr_sects;
132
133 strlcat(state->pp_buf, " [Linux]", PAGE_SIZE);
134
135 put_partition(state, slot++, first_sect, size);
136
137 linuxp = read_part_sector(state, first_sect, §);
138 if (!linuxp)
139 return -1;
140
141 strlcat(state->pp_buf, " <", PAGE_SIZE);
142 while (linuxp->magic == cpu_to_le32(LINUX_NATIVE_MAGIC) ||
143 linuxp->magic == cpu_to_le32(LINUX_SWAP_MAGIC)) {
144 if (slot == state->limit)
145 break;
146 put_partition(state, slot++, first_sect +
147 le32_to_cpu(linuxp->start_sect),
148 le32_to_cpu(linuxp->nr_sects));
149 linuxp ++;
150 }
151 strlcat(state->pp_buf, " >", PAGE_SIZE);
152
153 put_dev_sector(sect);
154 return slot;
155 }
156 #endif
157
158 #ifdef CONFIG_ACORN_PARTITION_CUMANA
adfspart_check_CUMANA(struct parsed_partitions * state)159 int adfspart_check_CUMANA(struct parsed_partitions *state)
160 {
161 unsigned long first_sector = 0;
162 unsigned int start_blk = 0;
163 Sector sect;
164 unsigned char *data;
165 char *name = "CUMANA/ADFS";
166 int first = 1;
167 int slot = 1;
168
169 /*
170 * Try Cumana style partitions - sector 6 contains ADFS boot block
171 * with pointer to next 'drive'.
172 *
173 * There are unknowns in this code - is the 'cylinder number' of the
174 * next partition relative to the start of this one - I'm assuming
175 * it is.
176 *
177 * Also, which ID did Cumana use?
178 *
179 * This is totally unfinished, and will require more work to get it
180 * going. Hence it is totally untested.
181 */
182 do {
183 struct adfs_discrecord *dr;
184 unsigned int nr_sects;
185
186 data = read_part_sector(state, start_blk * 2 + 6, §);
187 if (!data)
188 return -1;
189
190 if (slot == state->limit)
191 break;
192
193 dr = adfs_partition(state, name, data, first_sector, slot++);
194 if (!dr)
195 break;
196
197 name = NULL;
198
199 nr_sects = (data[0x1fd] + (data[0x1fe] << 8)) *
200 (dr->heads + (dr->lowsector & 0x40 ? 1 : 0)) *
201 dr->secspertrack;
202
203 if (!nr_sects)
204 break;
205
206 first = 0;
207 first_sector += nr_sects;
208 start_blk += nr_sects >> (BLOCK_SIZE_BITS - 9);
209 nr_sects = 0; /* hmm - should be partition size */
210
211 switch (data[0x1fc] & 15) {
212 case 0: /* No partition / ADFS? */
213 break;
214
215 #ifdef CONFIG_ACORN_PARTITION_RISCIX
216 case PARTITION_RISCIX_SCSI:
217 /* RISCiX - we don't know how to find the next one. */
218 slot = riscix_partition(state, first_sector, slot,
219 nr_sects);
220 break;
221 #endif
222
223 case PARTITION_LINUX:
224 slot = linux_partition(state, first_sector, slot,
225 nr_sects);
226 break;
227 }
228 put_dev_sector(sect);
229 if (slot == -1)
230 return -1;
231 } while (1);
232 put_dev_sector(sect);
233 return first ? 0 : 1;
234 }
235 #endif
236
237 #ifdef CONFIG_ACORN_PARTITION_ADFS
238 /*
239 * Purpose: allocate ADFS partitions.
240 *
241 * Params : hd - pointer to gendisk structure to store partition info.
242 * dev - device number to access.
243 *
244 * Returns: -1 on error, 0 for no ADFS boot sector, 1 for ok.
245 *
246 * Alloc : hda = whole drive
247 * hda1 = ADFS partition on first drive.
248 * hda2 = non-ADFS partition.
249 */
adfspart_check_ADFS(struct parsed_partitions * state)250 int adfspart_check_ADFS(struct parsed_partitions *state)
251 {
252 unsigned long start_sect, nr_sects, sectscyl, heads;
253 Sector sect;
254 unsigned char *data;
255 struct adfs_discrecord *dr;
256 unsigned char id;
257 int slot = 1;
258
259 data = read_part_sector(state, 6, §);
260 if (!data)
261 return -1;
262
263 dr = adfs_partition(state, "ADFS", data, 0, slot++);
264 if (!dr) {
265 put_dev_sector(sect);
266 return 0;
267 }
268
269 heads = dr->heads + ((dr->lowsector >> 6) & 1);
270 sectscyl = dr->secspertrack * heads;
271 start_sect = ((data[0x1fe] << 8) + data[0x1fd]) * sectscyl;
272 id = data[0x1fc] & 15;
273 put_dev_sector(sect);
274
275 /*
276 * Work out start of non-adfs partition.
277 */
278 nr_sects = get_capacity(state->disk) - start_sect;
279
280 if (start_sect) {
281 switch (id) {
282 #ifdef CONFIG_ACORN_PARTITION_RISCIX
283 case PARTITION_RISCIX_SCSI:
284 case PARTITION_RISCIX_MFM:
285 riscix_partition(state, start_sect, slot,
286 nr_sects);
287 break;
288 #endif
289
290 case PARTITION_LINUX:
291 linux_partition(state, start_sect, slot,
292 nr_sects);
293 break;
294 }
295 }
296 strlcat(state->pp_buf, "\n", PAGE_SIZE);
297 return 1;
298 }
299 #endif
300
301 #ifdef CONFIG_ACORN_PARTITION_ICS
302
303 struct ics_part {
304 __le32 start;
305 __le32 size;
306 };
307
adfspart_check_ICSLinux(struct parsed_partitions * state,unsigned long block)308 static int adfspart_check_ICSLinux(struct parsed_partitions *state,
309 unsigned long block)
310 {
311 Sector sect;
312 unsigned char *data = read_part_sector(state, block, §);
313 int result = 0;
314
315 if (data) {
316 if (memcmp(data, "LinuxPart", 9) == 0)
317 result = 1;
318 put_dev_sector(sect);
319 }
320
321 return result;
322 }
323
324 /*
325 * Check for a valid ICS partition using the checksum.
326 */
valid_ics_sector(const unsigned char * data)327 static inline int valid_ics_sector(const unsigned char *data)
328 {
329 unsigned long sum;
330 int i;
331
332 for (i = 0, sum = 0x50617274; i < 508; i++)
333 sum += data[i];
334
335 sum -= le32_to_cpu(*(__le32 *)(&data[508]));
336
337 return sum == 0;
338 }
339
340 /*
341 * Purpose: allocate ICS partitions.
342 * Params : hd - pointer to gendisk structure to store partition info.
343 * dev - device number to access.
344 * Returns: -1 on error, 0 for no ICS table, 1 for partitions ok.
345 * Alloc : hda = whole drive
346 * hda1 = ADFS partition 0 on first drive.
347 * hda2 = ADFS partition 1 on first drive.
348 * ..etc..
349 */
adfspart_check_ICS(struct parsed_partitions * state)350 int adfspart_check_ICS(struct parsed_partitions *state)
351 {
352 const unsigned char *data;
353 const struct ics_part *p;
354 int slot;
355 Sector sect;
356
357 /*
358 * Try ICS style partitions - sector 0 contains partition info.
359 */
360 data = read_part_sector(state, 0, §);
361 if (!data)
362 return -1;
363
364 if (!valid_ics_sector(data)) {
365 put_dev_sector(sect);
366 return 0;
367 }
368
369 strlcat(state->pp_buf, " [ICS]", PAGE_SIZE);
370
371 for (slot = 1, p = (const struct ics_part *)data; p->size; p++) {
372 u32 start = le32_to_cpu(p->start);
373 s32 size = le32_to_cpu(p->size); /* yes, it's signed. */
374
375 if (slot == state->limit)
376 break;
377
378 /*
379 * Negative sizes tell the RISC OS ICS driver to ignore
380 * this partition - in effect it says that this does not
381 * contain an ADFS filesystem.
382 */
383 if (size < 0) {
384 size = -size;
385
386 /*
387 * Our own extension - We use the first sector
388 * of the partition to identify what type this
389 * partition is. We must not make this visible
390 * to the filesystem.
391 */
392 if (size > 1 && adfspart_check_ICSLinux(state, start)) {
393 start += 1;
394 size -= 1;
395 }
396 }
397
398 if (size)
399 put_partition(state, slot++, start, size);
400 }
401
402 put_dev_sector(sect);
403 strlcat(state->pp_buf, "\n", PAGE_SIZE);
404 return 1;
405 }
406 #endif
407
408 #ifdef CONFIG_ACORN_PARTITION_POWERTEC
409 struct ptec_part {
410 __le32 unused1;
411 __le32 unused2;
412 __le32 start;
413 __le32 size;
414 __le32 unused5;
415 char type[8];
416 };
417
valid_ptec_sector(const unsigned char * data)418 static inline int valid_ptec_sector(const unsigned char *data)
419 {
420 unsigned char checksum = 0x2a;
421 int i;
422
423 /*
424 * If it looks like a PC/BIOS partition, then it
425 * probably isn't PowerTec.
426 */
427 if (data[510] == 0x55 && data[511] == 0xaa)
428 return 0;
429
430 for (i = 0; i < 511; i++)
431 checksum += data[i];
432
433 return checksum == data[511];
434 }
435
436 /*
437 * Purpose: allocate ICS partitions.
438 * Params : hd - pointer to gendisk structure to store partition info.
439 * dev - device number to access.
440 * Returns: -1 on error, 0 for no ICS table, 1 for partitions ok.
441 * Alloc : hda = whole drive
442 * hda1 = ADFS partition 0 on first drive.
443 * hda2 = ADFS partition 1 on first drive.
444 * ..etc..
445 */
adfspart_check_POWERTEC(struct parsed_partitions * state)446 int adfspart_check_POWERTEC(struct parsed_partitions *state)
447 {
448 Sector sect;
449 const unsigned char *data;
450 const struct ptec_part *p;
451 int slot = 1;
452 int i;
453
454 data = read_part_sector(state, 0, §);
455 if (!data)
456 return -1;
457
458 if (!valid_ptec_sector(data)) {
459 put_dev_sector(sect);
460 return 0;
461 }
462
463 strlcat(state->pp_buf, " [POWERTEC]", PAGE_SIZE);
464
465 for (i = 0, p = (const struct ptec_part *)data; i < 12; i++, p++) {
466 u32 start = le32_to_cpu(p->start);
467 u32 size = le32_to_cpu(p->size);
468
469 if (size)
470 put_partition(state, slot++, start, size);
471 }
472
473 put_dev_sector(sect);
474 strlcat(state->pp_buf, "\n", PAGE_SIZE);
475 return 1;
476 }
477 #endif
478
479 #ifdef CONFIG_ACORN_PARTITION_EESOX
480 struct eesox_part {
481 char magic[6];
482 char name[10];
483 __le32 start;
484 __le32 unused6;
485 __le32 unused7;
486 __le32 unused8;
487 };
488
489 /*
490 * Guess who created this format?
491 */
492 static const char eesox_name[] = {
493 'N', 'e', 'i', 'l', ' ',
494 'C', 'r', 'i', 't', 'c', 'h', 'e', 'l', 'l', ' ', ' '
495 };
496
497 /*
498 * EESOX SCSI partition format.
499 *
500 * This is a goddamned awful partition format. We don't seem to store
501 * the size of the partition in this table, only the start addresses.
502 *
503 * There are two possibilities where the size comes from:
504 * 1. The individual ADFS boot block entries that are placed on the disk.
505 * 2. The start address of the next entry.
506 */
adfspart_check_EESOX(struct parsed_partitions * state)507 int adfspart_check_EESOX(struct parsed_partitions *state)
508 {
509 Sector sect;
510 const unsigned char *data;
511 unsigned char buffer[256];
512 struct eesox_part *p;
513 sector_t start = 0;
514 int i, slot = 1;
515
516 data = read_part_sector(state, 7, §);
517 if (!data)
518 return -1;
519
520 /*
521 * "Decrypt" the partition table. God knows why...
522 */
523 for (i = 0; i < 256; i++)
524 buffer[i] = data[i] ^ eesox_name[i & 15];
525
526 put_dev_sector(sect);
527
528 for (i = 0, p = (struct eesox_part *)buffer; i < 8; i++, p++) {
529 sector_t next;
530
531 if (memcmp(p->magic, "Eesox", 6))
532 break;
533
534 next = le32_to_cpu(p->start);
535 if (i)
536 put_partition(state, slot++, start, next - start);
537 start = next;
538 }
539
540 if (i != 0) {
541 sector_t size;
542
543 size = get_capacity(state->disk);
544 put_partition(state, slot++, start, size - start);
545 strlcat(state->pp_buf, "\n", PAGE_SIZE);
546 }
547
548 return i ? 1 : 0;
549 }
550 #endif
551