1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2001
4  * Raymond Lo, lo@routefree.com
5  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
6  */
7 
8 /*
9  * Support for harddisk partitions.
10  *
11  * To be compatible with LinuxPPC and Apple we use the standard Apple
12  * SCSI disk partitioning scheme. For more information see:
13  * http://developer.apple.com/techpubs/mac/Devices/Devices-126.html#MARKER-14-92
14  */
15 
16 #include <common.h>
17 #include <blk.h>
18 #include <command.h>
19 #include <ide.h>
20 #include <memalign.h>
21 #include <asm/unaligned.h>
22 #include <linux/compiler.h>
23 #include "part_dos.h"
24 #include <part.h>
25 
26 #ifdef CONFIG_HAVE_BLOCK_DEVICE
27 
28 #define DOS_PART_DEFAULT_SECTOR 512
29 
30 /* should this be configurable? It looks like it's not very common at all
31  * to use large numbers of partitions */
32 #define MAX_EXT_PARTS 256
33 
is_extended(int part_type)34 static inline int is_extended(int part_type)
35 {
36     return (part_type == DOS_PART_TYPE_EXTENDED ||
37 	    part_type == DOS_PART_TYPE_EXTENDED_LBA ||
38 	    part_type == DOS_PART_TYPE_EXTENDED_LINUX);
39 }
40 
get_bootable(dos_partition_t * p)41 static int get_bootable(dos_partition_t *p)
42 {
43 	int ret = 0;
44 
45 	if (p->sys_ind == 0xef)
46 		ret |= PART_EFI_SYSTEM_PARTITION;
47 	if (p->boot_ind == 0x80)
48 		ret |= PART_BOOTABLE;
49 	return ret;
50 }
51 
print_one_part(dos_partition_t * p,lbaint_t ext_part_sector,int part_num,unsigned int disksig)52 static void print_one_part(dos_partition_t *p, lbaint_t ext_part_sector,
53 			   int part_num, unsigned int disksig)
54 {
55 	lbaint_t lba_start = ext_part_sector + get_unaligned_le32(p->start4);
56 	lbaint_t lba_size  = get_unaligned_le32(p->size4);
57 
58 	printf("%3d\t%-10" LBAFlength "u\t%-10" LBAFlength
59 		"u\t%08x-%02x\t%02x%s%s\n",
60 		part_num, lba_start, lba_size, disksig, part_num, p->sys_ind,
61 		(is_extended(p->sys_ind) ? " Extd" : ""),
62 		(get_bootable(p) ? " Boot" : ""));
63 }
64 
test_block_type(unsigned char * buffer)65 static int test_block_type(unsigned char *buffer)
66 {
67 	int slot;
68 	struct dos_partition *p;
69 	int part_count = 0;
70 
71 	if((buffer[DOS_PART_MAGIC_OFFSET + 0] != 0x55) ||
72 	    (buffer[DOS_PART_MAGIC_OFFSET + 1] != 0xaa) ) {
73 		return (-1);
74 	} /* no DOS Signature at all */
75 	p = (struct dos_partition *)&buffer[DOS_PART_TBL_OFFSET];
76 
77 	/* Check that the boot indicators are valid and count the partitions. */
78 	for (slot = 0; slot < 4; ++slot, ++p) {
79 		if (p->boot_ind != 0 && p->boot_ind != 0x80)
80 			break;
81 		if (p->sys_ind)
82 			++part_count;
83 	}
84 
85 	/*
86 	 * If the partition table is invalid or empty,
87 	 * check if this is a DOS PBR
88 	 */
89 	if (slot != 4 || !part_count) {
90 		if (!strncmp((char *)&buffer[DOS_PBR_FSTYPE_OFFSET],
91 			     "FAT", 3) ||
92 		    !strncmp((char *)&buffer[DOS_PBR32_FSTYPE_OFFSET],
93 			     "FAT32", 5))
94 			return DOS_PBR; /* This is a DOS PBR and not an MBR */
95 	}
96 	if (slot == 4)
97 		return DOS_MBR;	/* This is an DOS MBR */
98 
99 	/* This is neither a DOS MBR nor a DOS PBR */
100 	return -1;
101 }
102 
part_test_dos(struct blk_desc * dev_desc)103 static int part_test_dos(struct blk_desc *dev_desc)
104 {
105 #ifndef CONFIG_SPL_BUILD
106 	ALLOC_CACHE_ALIGN_BUFFER(legacy_mbr, mbr,
107 			DIV_ROUND_UP(dev_desc->blksz, sizeof(legacy_mbr)));
108 
109 	if (blk_dread(dev_desc, 0, 1, (ulong *)mbr) != 1)
110 		return -1;
111 
112 	if (test_block_type((unsigned char *)mbr) != DOS_MBR)
113 		return -1;
114 
115 	if (dev_desc->sig_type == SIG_TYPE_NONE &&
116 	    mbr->unique_mbr_signature != 0) {
117 		dev_desc->sig_type = SIG_TYPE_MBR;
118 		dev_desc->mbr_sig = mbr->unique_mbr_signature;
119 	}
120 #else
121 	ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, dev_desc->blksz);
122 
123 	if (blk_dread(dev_desc, 0, 1, (ulong *)buffer) != 1)
124 		return -1;
125 
126 	if (test_block_type(buffer) != DOS_MBR)
127 		return -1;
128 #endif
129 
130 	return 0;
131 }
132 
133 /*  Print a partition that is relative to its Extended partition table
134  */
print_partition_extended(struct blk_desc * dev_desc,lbaint_t ext_part_sector,lbaint_t relative,int part_num,unsigned int disksig)135 static void print_partition_extended(struct blk_desc *dev_desc,
136 				     lbaint_t ext_part_sector,
137 				     lbaint_t relative,
138 				     int part_num, unsigned int disksig)
139 {
140 	ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, dev_desc->blksz);
141 	dos_partition_t *pt;
142 	int i;
143 
144 	/* set a maximum recursion level */
145 	if (part_num > MAX_EXT_PARTS)
146 	{
147 		printf("** Nested DOS partitions detected, stopping **\n");
148 		return;
149     }
150 
151 	if (blk_dread(dev_desc, ext_part_sector, 1, (ulong *)buffer) != 1) {
152 		printf ("** Can't read partition table on %d:" LBAFU " **\n",
153 			dev_desc->devnum, ext_part_sector);
154 		return;
155 	}
156 	i=test_block_type(buffer);
157 	if (i != DOS_MBR) {
158 		printf ("bad MBR sector signature 0x%02x%02x\n",
159 			buffer[DOS_PART_MAGIC_OFFSET],
160 			buffer[DOS_PART_MAGIC_OFFSET + 1]);
161 		return;
162 	}
163 
164 	if (!ext_part_sector)
165 		disksig = get_unaligned_le32(&buffer[DOS_PART_DISKSIG_OFFSET]);
166 
167 	/* Print all primary/logical partitions */
168 	pt = (dos_partition_t *) (buffer + DOS_PART_TBL_OFFSET);
169 	for (i = 0; i < 4; i++, pt++) {
170 		/*
171 		 * fdisk does not show the extended partitions that
172 		 * are not in the MBR
173 		 */
174 
175 		if ((pt->sys_ind != 0) &&
176 		    (ext_part_sector == 0 || !is_extended (pt->sys_ind)) ) {
177 			print_one_part(pt, ext_part_sector, part_num, disksig);
178 		}
179 
180 		/* Reverse engr the fdisk part# assignment rule! */
181 		if ((ext_part_sector == 0) ||
182 		    (pt->sys_ind != 0 && !is_extended (pt->sys_ind)) ) {
183 			part_num++;
184 		}
185 	}
186 
187 	/* Follows the extended partitions */
188 	pt = (dos_partition_t *) (buffer + DOS_PART_TBL_OFFSET);
189 	for (i = 0; i < 4; i++, pt++) {
190 		if (is_extended (pt->sys_ind)) {
191 			lbaint_t lba_start
192 				= get_unaligned_le32 (pt->start4) + relative;
193 
194 			print_partition_extended(dev_desc, lba_start,
195 				ext_part_sector == 0  ? lba_start : relative,
196 				part_num, disksig);
197 		}
198 	}
199 
200 	return;
201 }
202 
203 
204 /*  Print a partition that is relative to its Extended partition table
205  */
part_get_info_extended(struct blk_desc * dev_desc,lbaint_t ext_part_sector,lbaint_t relative,int part_num,int which_part,struct disk_partition * info,uint disksig)206 static int part_get_info_extended(struct blk_desc *dev_desc,
207 				  lbaint_t ext_part_sector, lbaint_t relative,
208 				  int part_num, int which_part,
209 				  struct disk_partition *info, uint disksig)
210 {
211 	ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, dev_desc->blksz);
212 	dos_partition_t *pt;
213 	int i;
214 	int dos_type;
215 
216 	/* set a maximum recursion level */
217 	if (part_num > MAX_EXT_PARTS)
218 	{
219 		printf("** Nested DOS partitions detected, stopping **\n");
220 		return -1;
221     }
222 
223 	if (blk_dread(dev_desc, ext_part_sector, 1, (ulong *)buffer) != 1) {
224 		printf ("** Can't read partition table on %d:" LBAFU " **\n",
225 			dev_desc->devnum, ext_part_sector);
226 		return -1;
227 	}
228 	if (buffer[DOS_PART_MAGIC_OFFSET] != 0x55 ||
229 		buffer[DOS_PART_MAGIC_OFFSET + 1] != 0xaa) {
230 		printf ("bad MBR sector signature 0x%02x%02x\n",
231 			buffer[DOS_PART_MAGIC_OFFSET],
232 			buffer[DOS_PART_MAGIC_OFFSET + 1]);
233 		return -1;
234 	}
235 
236 #if CONFIG_IS_ENABLED(PARTITION_UUIDS)
237 	if (!ext_part_sector)
238 		disksig = get_unaligned_le32(&buffer[DOS_PART_DISKSIG_OFFSET]);
239 #endif
240 
241 	/* Print all primary/logical partitions */
242 	pt = (dos_partition_t *) (buffer + DOS_PART_TBL_OFFSET);
243 	for (i = 0; i < 4; i++, pt++) {
244 		/*
245 		 * fdisk does not show the extended partitions that
246 		 * are not in the MBR
247 		 */
248 		if (((pt->boot_ind & ~0x80) == 0) &&
249 		    (pt->sys_ind != 0) &&
250 		    (part_num == which_part) &&
251 		    (ext_part_sector == 0 || is_extended(pt->sys_ind) == 0)) {
252 			info->blksz = DOS_PART_DEFAULT_SECTOR;
253 			info->start = (lbaint_t)(ext_part_sector +
254 					get_unaligned_le32(pt->start4));
255 			info->size  = (lbaint_t)get_unaligned_le32(pt->size4);
256 			part_set_generic_name(dev_desc, part_num,
257 					      (char *)info->name);
258 			/* sprintf(info->type, "%d, pt->sys_ind); */
259 			strcpy((char *)info->type, "U-Boot");
260 			info->bootable = get_bootable(pt);
261 #if CONFIG_IS_ENABLED(PARTITION_UUIDS)
262 			sprintf(info->uuid, "%08x-%02x", disksig, part_num);
263 #endif
264 			info->sys_ind = pt->sys_ind;
265 			return 0;
266 		}
267 
268 		/* Reverse engr the fdisk part# assignment rule! */
269 		if ((ext_part_sector == 0) ||
270 		    (pt->sys_ind != 0 && !is_extended (pt->sys_ind)) ) {
271 			part_num++;
272 		}
273 	}
274 
275 	/* Follows the extended partitions */
276 	pt = (dos_partition_t *) (buffer + DOS_PART_TBL_OFFSET);
277 	for (i = 0; i < 4; i++, pt++) {
278 		if (is_extended (pt->sys_ind)) {
279 			lbaint_t lba_start
280 				= get_unaligned_le32 (pt->start4) + relative;
281 
282 			return part_get_info_extended(dev_desc, lba_start,
283 				 ext_part_sector == 0 ? lba_start : relative,
284 				 part_num, which_part, info, disksig);
285 		}
286 	}
287 
288 	/* Check for DOS PBR if no partition is found */
289 	dos_type = test_block_type(buffer);
290 
291 	if (dos_type == DOS_PBR) {
292 		info->start = 0;
293 		info->size = dev_desc->lba;
294 		info->blksz = DOS_PART_DEFAULT_SECTOR;
295 		info->bootable = 0;
296 		strcpy((char *)info->type, "U-Boot");
297 #if CONFIG_IS_ENABLED(PARTITION_UUIDS)
298 		info->uuid[0] = 0;
299 #endif
300 		return 0;
301 	}
302 
303 	return -1;
304 }
305 
part_print_dos(struct blk_desc * dev_desc)306 static void __maybe_unused part_print_dos(struct blk_desc *dev_desc)
307 {
308 	printf("Part\tStart Sector\tNum Sectors\tUUID\t\tType\n");
309 	print_partition_extended(dev_desc, 0, 0, 1, 0);
310 }
311 
part_get_info_dos(struct blk_desc * dev_desc,int part,struct disk_partition * info)312 static int __maybe_unused part_get_info_dos(struct blk_desc *dev_desc, int part,
313 		      struct disk_partition *info)
314 {
315 	return part_get_info_extended(dev_desc, 0, 0, 1, part, info, 0);
316 }
317 
is_valid_dos_buf(void * buf)318 int is_valid_dos_buf(void *buf)
319 {
320 	return test_block_type(buf) == DOS_MBR ? 0 : -1;
321 }
322 
323 #if CONFIG_IS_ENABLED(CMD_MBR)
lba_to_chs(lbaint_t lba,unsigned char * rc,unsigned char * rh,unsigned char * rs)324 static void lba_to_chs(lbaint_t lba, unsigned char *rc, unsigned char *rh,
325 		       unsigned char *rs)
326 {
327 	unsigned int c, h, s;
328 	/* use fixed CHS geometry */
329 	unsigned int sectpertrack = 63;
330 	unsigned int heads = 255;
331 
332 	c = (lba + 1) / sectpertrack / heads;
333 	h = (lba + 1) / sectpertrack - c * heads;
334 	s = (lba + 1) - (c * heads + h) * sectpertrack;
335 
336 	if (c > 1023) {
337 		c = 1023;
338 		h = 254;
339 		s = 63;
340 	}
341 
342 	*rc = c & 0xff;
343 	*rh = h;
344 	*rs = s + ((c & 0x300) >> 2);
345 }
346 
mbr_fill_pt_entry(dos_partition_t * pt,lbaint_t start,lbaint_t relative,lbaint_t size,uchar sys_ind,bool bootable)347 static void mbr_fill_pt_entry(dos_partition_t *pt, lbaint_t start,
348 		lbaint_t relative, lbaint_t size, uchar sys_ind, bool bootable)
349 {
350 	pt->boot_ind = bootable ? 0x80 : 0x00;
351 	pt->sys_ind = sys_ind;
352 	lba_to_chs(start, &pt->cyl, &pt->head, &pt->sector);
353 	lba_to_chs(start + size - 1, &pt->end_cyl, &pt->end_head, &pt->end_sector);
354 	put_unaligned_le32(relative, &pt->start4);
355 	put_unaligned_le32(size, &pt->size4);
356 }
357 
write_mbr_partitions(struct blk_desc * dev,struct disk_partition * p,int count,unsigned int disksig)358 int write_mbr_partitions(struct blk_desc *dev,
359 		struct disk_partition *p, int count, unsigned int disksig)
360 {
361 	ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, dev->blksz);
362 	lbaint_t ext_part_start = 0, ext_part_size = 0, ext_part_sect = 0;
363 	dos_partition_t *pt;
364 	int i;
365 
366 	memset(buffer, 0, dev->blksz);
367 	buffer[DOS_PART_MAGIC_OFFSET] = 0x55;
368 	buffer[DOS_PART_MAGIC_OFFSET + 1] = 0xaa;
369 	put_unaligned_le32(disksig, &buffer[DOS_PART_DISKSIG_OFFSET]);
370 	pt = (dos_partition_t *) (buffer + DOS_PART_TBL_OFFSET);
371 
372 	/* create all primary partitions */
373 	for (i = 0; i < 4 && i < count; i++, pt++) {
374 		mbr_fill_pt_entry(pt, p[i].start, p[i].start, p[i].size,
375 				  p[i].sys_ind, p[i].bootable);
376 		if (is_extended(p[i].sys_ind)) {
377 			ext_part_start = p[i].start;
378 			ext_part_size = p[i].size;
379 			ext_part_sect = p[i].start;
380 		}
381 	}
382 
383 	if (i < count && !ext_part_start) {
384 		printf("%s: extended partition is needed for more than 4 partitions\n",
385 		        __func__);
386 		return -1;
387 	}
388 
389 	/* write MBR */
390 	if (blk_dwrite(dev, 0, 1, buffer) != 1) {
391 		printf("%s: failed writing 'MBR' (1 blks at 0x0)\n",
392 		       __func__);
393 		return -1;
394 	}
395 
396 	/* create extended volumes */
397 	for (; i < count; i++) {
398 		lbaint_t next_ebr = 0;
399 
400 		memset(buffer, 0, dev->blksz);
401 		buffer[DOS_PART_MAGIC_OFFSET] = 0x55;
402 		buffer[DOS_PART_MAGIC_OFFSET + 1] = 0xaa;
403 		pt = (dos_partition_t *) (buffer + DOS_PART_TBL_OFFSET);
404 
405 		mbr_fill_pt_entry(pt, p[i].start, p[i].start - ext_part_sect,
406 				  p[i].size, p[i].sys_ind, p[i].bootable);
407 
408 		if (i + 1 < count) {
409 			pt++;
410 			next_ebr = p[i].start + p[i].size;
411 			mbr_fill_pt_entry(pt, next_ebr,
412 					  next_ebr - ext_part_start,
413 					  p[i+1].start + p[i+1].size - next_ebr,
414 					  DOS_PART_TYPE_EXTENDED, 0);
415 		}
416 
417 		/* write EBR */
418 		if (blk_dwrite(dev, ext_part_sect, 1, buffer) != 1) {
419 			printf("%s: failed writing 'EBR' (1 blks at 0x%lx)\n",
420 			       __func__, ext_part_sect);
421 			return -1;
422 		}
423 		ext_part_sect = next_ebr;
424 	}
425 
426 	/* Update the partition table entries*/
427 	part_init(dev);
428 
429 	return 0;
430 }
431 
layout_mbr_partitions(struct disk_partition * p,int count,lbaint_t total_sectors)432 int layout_mbr_partitions(struct disk_partition *p, int count,
433 			  lbaint_t total_sectors)
434 {
435 	struct disk_partition *ext = NULL;
436 	int i, j;
437 	lbaint_t ext_vol_start;
438 
439 	/* calculate primary partitions start and size if needed */
440 	if (!p[0].start)
441 		p[0].start = DOS_PART_DEFAULT_GAP;
442 	for (i = 0; i < 4 && i < count; i++) {
443 		if (!p[i].start)
444 			p[i].start = p[i - 1].start + p[i - 1].size;
445 		if (!p[i].size) {
446 			lbaint_t end = total_sectors;
447 			lbaint_t allocated = 0;
448 
449 			for (j = i + 1; j < 4 && j < count; j++) {
450 				if (p[j].start) {
451 					end = p[j].start;
452 					break;
453 				}
454 				allocated += p[j].size;
455 			}
456 			p[i].size = end - allocated - p[i].start;
457 		}
458 		if (p[i].sys_ind == 0x05)
459 			ext = &p[i];
460 	}
461 
462 	if (i >= 4 && !ext) {
463 		printf("%s: extended partition is needed for more than 4 partitions\n",
464 		        __func__);
465 		return -1;
466 	}
467 
468 	/* calculate extended volumes start and size if needed */
469 	ext_vol_start = ext->start;
470 	for (i = 4; i < count; i++) {
471 		if (!p[i].start)
472 			p[i].start = ext_vol_start + DOS_PART_DEFAULT_GAP;
473 		if (!p[i].size) {
474 			lbaint_t end = ext->start + ext->size;
475 			lbaint_t allocated = 0;
476 
477 			for (j = i + 1; j < count; j++) {
478 				if (p[j].start) {
479 					end = p[j].start - DOS_PART_DEFAULT_GAP;
480 					break;
481 				}
482 				allocated += p[j].size + DOS_PART_DEFAULT_GAP;
483 			}
484 			p[i].size = end - allocated - p[i].start;
485 		}
486 		ext_vol_start = p[i].start + p[i].size;
487 	}
488 
489 	return 0;
490 }
491 #endif
492 
write_mbr_sector(struct blk_desc * dev_desc,void * buf)493 int write_mbr_sector(struct blk_desc *dev_desc, void *buf)
494 {
495 	if (is_valid_dos_buf(buf))
496 		return -1;
497 
498 	/* write MBR */
499 	if (blk_dwrite(dev_desc, 0, 1, buf) != 1) {
500 		printf("%s: failed writing '%s' (1 blks at 0x0)\n",
501 		       __func__, "MBR");
502 		return 1;
503 	}
504 
505 	/* Update the partition table entries*/
506 	part_init(dev_desc);
507 
508 	return 0;
509 }
510 
511 U_BOOT_PART_TYPE(dos) = {
512 	.name		= "DOS",
513 	.part_type	= PART_TYPE_DOS,
514 	.max_entries	= DOS_ENTRY_NUMBERS,
515 	.get_info	= part_get_info_ptr(part_get_info_dos),
516 	.print		= part_print_ptr(part_print_dos),
517 	.test		= part_test_dos,
518 };
519 
520 #endif
521