xref: /openbmc/u-boot/disk/part_dos.c (revision fb79a3bf) 
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 <command.h>
18 #include <ide.h>
19 #include <memalign.h>
20 #include "part_dos.h"
21 
22 #ifdef CONFIG_HAVE_BLOCK_DEVICE
23 
24 #define DOS_PART_DEFAULT_SECTOR 512
25 
26 /* should this be configurable? It looks like it's not very common at all
27  * to use large numbers of partitions */
28 #define MAX_EXT_PARTS 256
29 
30 /* Convert char[4] in little endian format to the host format integer
31  */
32 static inline unsigned int le32_to_int(unsigned char *le32)
33 {
34     return ((le32[3] << 24) +
35 	    (le32[2] << 16) +
36 	    (le32[1] << 8) +
37 	     le32[0]
38 	   );
39 }
40 
41 static inline int is_extended(int part_type)
42 {
43     return (part_type == 0x5 ||
44 	    part_type == 0xf ||
45 	    part_type == 0x85);
46 }
47 
48 static inline int is_bootable(dos_partition_t *p)
49 {
50 	return (p->sys_ind == 0xef) || (p->boot_ind == 0x80);
51 }
52 
53 static void print_one_part(dos_partition_t *p, lbaint_t ext_part_sector,
54 			   int part_num, unsigned int disksig)
55 {
56 	lbaint_t lba_start = ext_part_sector + le32_to_int (p->start4);
57 	lbaint_t lba_size  = le32_to_int (p->size4);
58 
59 	printf("%3d\t%-10" LBAFlength "u\t%-10" LBAFlength
60 		"u\t%08x-%02x\t%02x%s%s\n",
61 		part_num, lba_start, lba_size, disksig, part_num, p->sys_ind,
62 		(is_extended(p->sys_ind) ? " Extd" : ""),
63 		(is_bootable(p) ? " Boot" : ""));
64 }
65 
66 static int test_block_type(unsigned char *buffer)
67 {
68 	int slot;
69 	struct dos_partition *p;
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 	for (slot = 0; slot < 3; slot++) {
77 		if (p->boot_ind != 0 && p->boot_ind != 0x80) {
78 			if (!slot &&
79 			    (strncmp((char *)&buffer[DOS_PBR_FSTYPE_OFFSET],
80 				     "FAT", 3) == 0 ||
81 			     strncmp((char *)&buffer[DOS_PBR32_FSTYPE_OFFSET],
82 				     "FAT32", 5) == 0)) {
83 				return DOS_PBR; /* is PBR */
84 			} else {
85 				return -1;
86 			}
87 		}
88 	}
89 	return DOS_MBR;	    /* Is MBR */
90 }
91 
92 
93 static int part_test_dos(struct blk_desc *dev_desc)
94 {
95 #ifndef CONFIG_SPL_BUILD
96 	ALLOC_CACHE_ALIGN_BUFFER(legacy_mbr, mbr, 1);
97 
98 	if (blk_dread(dev_desc, 0, 1, (ulong *)mbr) != 1)
99 		return -1;
100 
101 	if (test_block_type((unsigned char *)mbr) != DOS_MBR)
102 		return -1;
103 
104 	if (dev_desc->sig_type == SIG_TYPE_NONE &&
105 	    mbr->unique_mbr_signature != 0) {
106 		dev_desc->sig_type = SIG_TYPE_MBR;
107 		dev_desc->mbr_sig = mbr->unique_mbr_signature;
108 	}
109 #else
110 	ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, dev_desc->blksz);
111 
112 	if (blk_dread(dev_desc, 0, 1, (ulong *)buffer) != 1)
113 		return -1;
114 
115 	if (test_block_type(buffer) != DOS_MBR)
116 		return -1;
117 #endif
118 
119 	return 0;
120 }
121 
122 /*  Print a partition that is relative to its Extended partition table
123  */
124 static void print_partition_extended(struct blk_desc *dev_desc,
125 				     lbaint_t ext_part_sector,
126 				     lbaint_t relative,
127 				     int part_num, unsigned int disksig)
128 {
129 	ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, dev_desc->blksz);
130 	dos_partition_t *pt;
131 	int i;
132 
133 	/* set a maximum recursion level */
134 	if (part_num > MAX_EXT_PARTS)
135 	{
136 		printf("** Nested DOS partitions detected, stopping **\n");
137 		return;
138     }
139 
140 	if (blk_dread(dev_desc, ext_part_sector, 1, (ulong *)buffer) != 1) {
141 		printf ("** Can't read partition table on %d:" LBAFU " **\n",
142 			dev_desc->devnum, ext_part_sector);
143 		return;
144 	}
145 	i=test_block_type(buffer);
146 	if (i != DOS_MBR) {
147 		printf ("bad MBR sector signature 0x%02x%02x\n",
148 			buffer[DOS_PART_MAGIC_OFFSET],
149 			buffer[DOS_PART_MAGIC_OFFSET + 1]);
150 		return;
151 	}
152 
153 	if (!ext_part_sector)
154 		disksig = le32_to_int(&buffer[DOS_PART_DISKSIG_OFFSET]);
155 
156 	/* Print all primary/logical partitions */
157 	pt = (dos_partition_t *) (buffer + DOS_PART_TBL_OFFSET);
158 	for (i = 0; i < 4; i++, pt++) {
159 		/*
160 		 * fdisk does not show the extended partitions that
161 		 * are not in the MBR
162 		 */
163 
164 		if ((pt->sys_ind != 0) &&
165 		    (ext_part_sector == 0 || !is_extended (pt->sys_ind)) ) {
166 			print_one_part(pt, ext_part_sector, part_num, disksig);
167 		}
168 
169 		/* Reverse engr the fdisk part# assignment rule! */
170 		if ((ext_part_sector == 0) ||
171 		    (pt->sys_ind != 0 && !is_extended (pt->sys_ind)) ) {
172 			part_num++;
173 		}
174 	}
175 
176 	/* Follows the extended partitions */
177 	pt = (dos_partition_t *) (buffer + DOS_PART_TBL_OFFSET);
178 	for (i = 0; i < 4; i++, pt++) {
179 		if (is_extended (pt->sys_ind)) {
180 			lbaint_t lba_start
181 				= le32_to_int (pt->start4) + relative;
182 
183 			print_partition_extended(dev_desc, lba_start,
184 				ext_part_sector == 0  ? lba_start : relative,
185 				part_num, disksig);
186 		}
187 	}
188 
189 	return;
190 }
191 
192 
193 /*  Print a partition that is relative to its Extended partition table
194  */
195 static int part_get_info_extended(struct blk_desc *dev_desc,
196 				  lbaint_t ext_part_sector, lbaint_t relative,
197 				  int part_num, int which_part,
198 				  disk_partition_t *info, unsigned int disksig)
199 {
200 	ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, dev_desc->blksz);
201 	dos_partition_t *pt;
202 	int i;
203 	int dos_type;
204 
205 	/* set a maximum recursion level */
206 	if (part_num > MAX_EXT_PARTS)
207 	{
208 		printf("** Nested DOS partitions detected, stopping **\n");
209 		return -1;
210     }
211 
212 	if (blk_dread(dev_desc, ext_part_sector, 1, (ulong *)buffer) != 1) {
213 		printf ("** Can't read partition table on %d:" LBAFU " **\n",
214 			dev_desc->devnum, ext_part_sector);
215 		return -1;
216 	}
217 	if (buffer[DOS_PART_MAGIC_OFFSET] != 0x55 ||
218 		buffer[DOS_PART_MAGIC_OFFSET + 1] != 0xaa) {
219 		printf ("bad MBR sector signature 0x%02x%02x\n",
220 			buffer[DOS_PART_MAGIC_OFFSET],
221 			buffer[DOS_PART_MAGIC_OFFSET + 1]);
222 		return -1;
223 	}
224 
225 #if CONFIG_IS_ENABLED(PARTITION_UUIDS)
226 	if (!ext_part_sector)
227 		disksig = le32_to_int(&buffer[DOS_PART_DISKSIG_OFFSET]);
228 #endif
229 
230 	/* Print all primary/logical partitions */
231 	pt = (dos_partition_t *) (buffer + DOS_PART_TBL_OFFSET);
232 	for (i = 0; i < 4; i++, pt++) {
233 		/*
234 		 * fdisk does not show the extended partitions that
235 		 * are not in the MBR
236 		 */
237 		if (((pt->boot_ind & ~0x80) == 0) &&
238 		    (pt->sys_ind != 0) &&
239 		    (part_num == which_part) &&
240 		    (ext_part_sector == 0 || is_extended(pt->sys_ind) == 0)) {
241 			info->blksz = DOS_PART_DEFAULT_SECTOR;
242 			info->start = (lbaint_t)(ext_part_sector +
243 					le32_to_int(pt->start4));
244 			info->size  = (lbaint_t)le32_to_int(pt->size4);
245 			part_set_generic_name(dev_desc, part_num,
246 					      (char *)info->name);
247 			/* sprintf(info->type, "%d, pt->sys_ind); */
248 			strcpy((char *)info->type, "U-Boot");
249 			info->bootable = is_bootable(pt);
250 #if CONFIG_IS_ENABLED(PARTITION_UUIDS)
251 			sprintf(info->uuid, "%08x-%02x", disksig, part_num);
252 #endif
253 			info->sys_ind = pt->sys_ind;
254 			return 0;
255 		}
256 
257 		/* Reverse engr the fdisk part# assignment rule! */
258 		if ((ext_part_sector == 0) ||
259 		    (pt->sys_ind != 0 && !is_extended (pt->sys_ind)) ) {
260 			part_num++;
261 		}
262 	}
263 
264 	/* Follows the extended partitions */
265 	pt = (dos_partition_t *) (buffer + DOS_PART_TBL_OFFSET);
266 	for (i = 0; i < 4; i++, pt++) {
267 		if (is_extended (pt->sys_ind)) {
268 			lbaint_t lba_start
269 				= le32_to_int (pt->start4) + relative;
270 
271 			return part_get_info_extended(dev_desc, lba_start,
272 				 ext_part_sector == 0 ? lba_start : relative,
273 				 part_num, which_part, info, disksig);
274 		}
275 	}
276 
277 	/* Check for DOS PBR if no partition is found */
278 	dos_type = test_block_type(buffer);
279 
280 	if (dos_type == DOS_PBR) {
281 		info->start = 0;
282 		info->size = dev_desc->lba;
283 		info->blksz = DOS_PART_DEFAULT_SECTOR;
284 		info->bootable = 0;
285 		strcpy((char *)info->type, "U-Boot");
286 #if CONFIG_IS_ENABLED(PARTITION_UUIDS)
287 		info->uuid[0] = 0;
288 #endif
289 		return 0;
290 	}
291 
292 	return -1;
293 }
294 
295 void part_print_dos(struct blk_desc *dev_desc)
296 {
297 	printf("Part\tStart Sector\tNum Sectors\tUUID\t\tType\n");
298 	print_partition_extended(dev_desc, 0, 0, 1, 0);
299 }
300 
301 int part_get_info_dos(struct blk_desc *dev_desc, int part,
302 		      disk_partition_t *info)
303 {
304 	return part_get_info_extended(dev_desc, 0, 0, 1, part, info, 0);
305 }
306 
307 int is_valid_dos_buf(void *buf)
308 {
309 	return test_block_type(buf) == DOS_MBR ? 0 : -1;
310 }
311 
312 int write_mbr_partition(struct blk_desc *dev_desc, void *buf)
313 {
314 	if (is_valid_dos_buf(buf))
315 		return -1;
316 
317 	/* write MBR */
318 	if (blk_dwrite(dev_desc, 0, 1, buf) != 1) {
319 		printf("%s: failed writing '%s' (1 blks at 0x0)\n",
320 		       __func__, "MBR");
321 		return 1;
322 	}
323 
324 	return 0;
325 }
326 
327 U_BOOT_PART_TYPE(dos) = {
328 	.name		= "DOS",
329 	.part_type	= PART_TYPE_DOS,
330 	.max_entries	= DOS_ENTRY_NUMBERS,
331 	.get_info	= part_get_info_ptr(part_get_info_dos),
332 	.print		= part_print_ptr(part_print_dos),
333 	.test		= part_test_dos,
334 };
335 
336 #endif
337