xref: /netbsd-src/external/gpl3/gdb/dist/sim/ppc/pk_disklabel.c (revision f89f6560d453f5e37386cc7938c072d2f528b9fa)
1 /*  This file is part of the program psim.
2 
3     Copyright (C) 1994-1997, Andrew Cagney <cagney@highland.com.au>
4 
5     This program is free software; you can redistribute it and/or modify
6     it under the terms of the GNU General Public License as published by
7     the Free Software Foundation; either version 3 of the License, or
8     (at your option) any later version.
9 
10     This program is distributed in the hope that it will be useful,
11     but WITHOUT ANY WARRANTY; without even the implied warranty of
12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13     GNU General Public License for more details.
14 
15     You should have received a copy of the GNU General Public License
16     along with this program; if not, see <http://www.gnu.org/licenses/>.
17 
18     */
19 
20 
21 #ifndef _PK_DISKLABEL_C_
22 #define _PK_DISKLABEL_C_
23 
24 #ifndef STATIC_INLINE_PK_DISKLABEL
25 #define STATIC_INLINE_PK_DISKLABEL STATIC_INLINE
26 #endif
27 
28 #include "device_table.h"
29 
30 #include "pk.h"
31 
32 #ifdef HAVE_STDLIB_H
33 #include <stdlib.h>
34 #endif
35 
36 
37 
38 /* PACKAGE
39 
40    disk-label - all knowing disk I/O package
41 
42    DESCRIPTION
43 
44    The disk-label package provides a generic interface to disk
45    devices.  It uses the arguments specified when an instance is being
46    created to determine if the raw disk, a partition, or a file within
47    a partition should be opened.
48 
49    An instance create call to disk-label could result, for instance,
50    in the opening of a DOS file system contained within a dos
51    partition contained within a physical disk.
52 
53    */
54 
55 /* taken from bfd/ppcboot.c by Michael Meissner */
56 
57 /* PPCbug location structure */
58 typedef struct ppcboot_location {
59   unsigned8 ind;
60   unsigned8 head;
61   unsigned8 sector;
62   unsigned8 cylinder;
63 } ppcboot_location_t;
64 
65 /* PPCbug partition table layout */
66 typedef struct ppcboot_partition {
67   ppcboot_location_t partition_begin;	/* partition begin */
68   ppcboot_location_t partition_end;	/* partition end */
69   unsigned8 sector_begin[4];		/* 32-bit start RBA (zero-based), little endian */
70   unsigned8 sector_length[4];		/* 32-bit RBA count (one-based), little endian */
71 } ppcboot_partition_t;
72 
73 #if 0
74 /* PPCbug boot layout.  */
75 typedef struct ppcboot_hdr {
76   unsigned8		pc_compatibility[446];	/* x86 instruction field */
77   ppcboot_partition_t	partition[4];		/* partition information */
78   unsigned8		signature[2];		/* 0x55 and 0xaa */
79   unsigned8		entry_offset[4];	/* entry point offset, little endian */
80   unsigned8		length[4];		/* load image length, little endian */
81   unsigned8		flags;			/* flag field */
82   unsigned8		os_id;			/* OS_ID */
83   char			partition_name[32];	/* partition name */
84   unsigned8		reserved1[470];		/* reserved */
85 } ppcboot_hdr_t;
86 #endif
87 
88 
89 typedef struct _disklabel {
90   device_instance *parent;
91   device_instance *raw_disk;
92   unsigned_word pos;
93   unsigned_word sector_begin;
94   unsigned_word sector_length;
95 } disklabel;
96 
97 
98 static unsigned_word
99 sector2uw(unsigned8 s[4])
100 {
101   return ((s[3] << 24)
102 	  + (s[2] << 16)
103 	  + (s[1] << 8)
104 	  + (s[0] << 0));
105 }
106 
107 
108 static void
109 disklabel_delete(device_instance *instance)
110 {
111   disklabel *label = device_instance_data(instance);
112   device_instance_delete(label->raw_disk);
113   free(label);
114 }
115 
116 
117 static int
118 disklabel_read(device_instance *instance,
119 	       void *buf,
120 	       unsigned_word len)
121 {
122   disklabel *label = device_instance_data(instance);
123   int nr_read;
124   if (label->pos + len > label->sector_length)
125     len = label->sector_length - label->pos;
126   if (device_instance_seek(label->raw_disk, 0,
127 			   label->sector_begin + label->pos) < 0)
128     return -1;
129   nr_read = device_instance_read(label->raw_disk, buf, len);
130   if (nr_read > 0)
131     label->pos += nr_read;
132   return nr_read;
133 }
134 
135 static int
136 disklabel_write(device_instance *instance,
137 		const void *buf,
138 		unsigned_word len)
139 {
140   disklabel *label = device_instance_data(instance);
141   int nr_written;
142   if (label->pos + len > label->sector_length)
143     len = label->sector_length - label->pos;
144   if (device_instance_seek(label->raw_disk, 0,
145 			   label->sector_begin + label->pos) < 0)
146     return -1;
147   nr_written = device_instance_write(label->raw_disk, buf, len);
148   if (nr_written > 0)
149     label->pos += nr_written;
150   return nr_written;
151 }
152 
153 static int
154 disklabel_seek(device_instance *instance,
155 	       unsigned_word pos_hi,
156 	       unsigned_word pos_lo)
157 {
158   disklabel *label = device_instance_data(instance);
159   if (pos_lo >= label->sector_length || pos_hi != 0)
160     return -1;
161   label->pos = pos_lo;
162   return 0;
163 }
164 
165 
166 static const device_instance_callbacks package_disklabel_callbacks = {
167   disklabel_delete,
168   disklabel_read,
169   disklabel_write,
170   disklabel_seek,
171 };
172 
173 /* Reconize different types of boot block */
174 
175 static int
176 block0_is_bpb(const unsigned8 block[])
177 {
178   const char ebdic_ibma[] = { 0xc9, 0xc2, 0xd4, 0xc1 };
179   /* ref PowerPC Microprocessor CHRP bindings 1.2b - page 47 */
180   /* can't start with IBMA */
181   if (memcmp(block, ebdic_ibma, sizeof(ebdic_ibma)) == 0)
182     return 0;
183   /* must have LE 0xAA55 signature at offset 510 */
184   if (block[511] != 0xAA && block[510] != 0x55)
185     return 0;
186   /* valid 16 bit LE bytes per sector - 256, 512, 1024 */
187   if (block[11] != 0
188       || (block[12] != 1 && block[12] != 2 && block[12] != 4))
189     return 0;
190   /* nr fats is 1 or 2 */
191   if (block[16] != 1 && block[16] != 2)
192     return 0;
193   return 1;
194 }
195 
196 
197 /* Verify that the device contains an ISO-9660 File system */
198 
199 static int
200 is_iso9660(device_instance *raw_disk)
201 {
202   /* ref PowerPC Microprocessor CHRP bindings 1.2b - page 47 */
203   unsigned8 block[512];
204   if (device_instance_seek(raw_disk, 0, 512 * 64) < 0)
205     return 0;
206   if (device_instance_read(raw_disk, block, sizeof(block)) != sizeof(block))
207     return 0;
208   if (block[0] == 0x01
209       && block[1] == 'C'
210       && block[2] == 'D'
211       && block[3] == '0'
212       && block[4] == '0'
213       && block[5] == '1')
214     return 1;
215   return 0;
216 }
217 
218 
219 /* Verify that the disk block contains a valid DOS partition table.
220    While we're at it have a look around for active partitions etc.
221 
222    Return 0: invalid
223    Return 1..4: valid, value returned is the first active partition
224    Return -1: no active partition */
225 
226 static int
227 block0_is_fdisk(const unsigned8 block[])
228 {
229   const int partition_type_fields[] = { 0, 0x1c2, 0x1d2, 0x1e2, 0x1f2 };
230   const int partition_active_fields[] = { 0, 0x1be, 0x1ce, 0x1de, 0xee };
231   int partition;
232   int active = -1;
233   /* ref PowerPC Microprocessor CHRP bindings 1.2b - page 47 */
234   /* must have LE 0xAA55 signature at offset 510 */
235   if (block[511/*0x1ff*/] != 0xAA && block[510/*0x1fe*/] != 0x55)
236     return 0;
237   /* must contain valid partition types */
238   for (partition = 1; partition <= 4 && active != 0; partition++) {
239     int partition_type = block[partition_type_fields[partition]];
240     int is_active = block[partition_active_fields[partition]] == 0x80;
241     const char *type;
242     switch (partition_type) {
243     case 0x00:
244       type = "UNUSED";
245       break;
246     case 0x01:
247       type = "FAT 12 File system";
248       break;
249     case 0x04:
250       type = "FAT 16 File system";
251       break;
252     case 0x05:
253     case 0x06:
254       type = "rejected - extended/chained partition not supported";
255       active = 0;
256       break;
257     case 0x41:
258       type = "Single program image";
259       break;
260     case 0x82:
261       type = "Solaris?";
262       break;
263     case 0x96:
264       type = "ISO 9660 File system";
265       break;
266     default:
267       type = "rejected - unknown type";
268       active = 0;
269       break;
270     }
271     PTRACE(disklabel, ("partition %d of type 0x%02x - %s%s\n",
272 		       partition,
273 		       partition_type,
274 		       type,
275 		       is_active && active != 0 ? " (active)" : ""));
276     if (partition_type != 0 && is_active && active < 0)
277       active = partition;
278   }
279   return active;
280 }
281 
282 
283 /* Verify that block0 corresponds to a MAC disk */
284 
285 static int
286 block0_is_mac_disk(const unsigned8 block[])
287 {
288   /* ref PowerPC Microprocessor CHRP bindings 1.2b - page 47 */
289   /* signature - BEx4552 at offset 0 */
290   if (block[0] != 0x45 || block[1] != 0x52)
291     return 0;
292   return 1;
293 }
294 
295 
296 /* Open a logical disk/file */
297 
298 device_instance *
299 pk_disklabel_create_instance(device_instance *raw_disk,
300 			     const char *args)
301 {
302   int partition;
303   char *filename;
304 
305   /* parse the arguments */
306   if (args == NULL) {
307     partition = 0;
308     filename = NULL;
309   }
310   else {
311     partition = strtoul((char*)args, &filename, 0);
312     if (filename == args)
313       partition = -1; /* not specified */
314     if (*filename == ',')
315       filename++;
316     if (*filename == '\0')
317       filename = NULL; /* easier */
318   }
319 
320   if (partition == 0) {
321     /* select the raw disk */
322     return raw_disk;
323   }
324   else {
325     unsigned8 boot_block[512];
326     /* get the boot block for examination */
327     if (device_instance_seek(raw_disk, 0, 0) < 0)
328       device_error(device_instance_device(raw_disk),
329 		   "Problem seeking on raw disk");
330     if (device_instance_read(raw_disk, &boot_block, sizeof(boot_block))
331 	!= sizeof(boot_block))
332       device_error(device_instance_device(raw_disk), "Problem reading boot block");
333 
334     if (partition < 0) {
335       /* select the active partition */
336       if (block0_is_bpb(boot_block)) {
337 	device_error(device_instance_device(raw_disk), "Unimplemented active BPB");
338       }
339       else if (block0_is_fdisk(boot_block)) {
340 	int active = block0_is_fdisk(boot_block);
341 	device_error(device_instance_device(raw_disk), "Unimplemented active FDISK (%d)",
342 		     active);
343       }
344       else if (is_iso9660(raw_disk)) {
345 	device_error(device_instance_device(raw_disk), "Unimplemented active ISO9660");
346       }
347       else if (block0_is_mac_disk(boot_block)) {
348 	device_error(device_instance_device(raw_disk), "Unimplemented active MAC DISK");
349       }
350       else {
351 	device_error(device_instance_device(raw_disk), "Unreconized bootblock");
352       }
353     }
354     else {
355       /* select the specified disk partition */
356       if (block0_is_bpb(boot_block)) {
357 	device_error(device_instance_device(raw_disk), "Unimplemented BPB");
358       }
359       else if (block0_is_fdisk(boot_block)) {
360 	/* return an instance */
361 	ppcboot_partition_t *partition_table = (ppcboot_partition_t*) &boot_block[446];
362 	ppcboot_partition_t *partition_entry;
363 	disklabel *label;
364 	if (partition > 4)
365 	  device_error(device_instance_device(raw_disk),
366 		       "Only FDISK partitions 1..4 supported");
367 	partition_entry = &partition_table[partition - 1];
368 	label = ZALLOC(disklabel);
369 	label->raw_disk = raw_disk;
370 	label->pos = 0;
371 	label->sector_begin = 512 * sector2uw(partition_entry->sector_begin);
372 	label->sector_length = 512 * sector2uw(partition_entry->sector_length);
373 	PTRACE(disklabel, ("partition %ld, sector-begin %ld, length %ld\n",
374 			   (long)partition,
375 			   (long)label->sector_begin,
376 			   (long)label->sector_length));
377 	if (filename != NULL)
378 	  device_error(device_instance_device(raw_disk),
379 		       "FDISK file names not yet supported");
380 	return device_create_instance_from(NULL, raw_disk,
381 					   label,
382 					   NULL, args,
383 					   &package_disklabel_callbacks);
384       }
385       else if (block0_is_mac_disk(boot_block)) {
386 	device_error(device_instance_device(raw_disk), "Unimplemented MAC DISK");
387       }
388       else {
389 	device_error(device_instance_device(raw_disk),
390 		     "Unreconized bootblock");
391       }
392     }
393   }
394 
395   return NULL;
396 }
397 
398 
399 #endif /* _PK_DISKLABEL_C_ */
400 
401