1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License, Version 1.0 only
6 * (the "License"). You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22 /*
23 * Copyright 2005 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 /*
28 * Basic file system reading code for standalone I/O system.
29 * Simulates a primitive UNIX I/O system (read(), write(), open(), etc).
30 * Does not support writes.
31 */
32
33 /*
34 * WARNING:
35 * This is currently used by installgrub for creating bootable floppy.
36 * The special part is diskread_callback/fileread_callback for gathering
37 * fileblock list.
38 */
39
40 #include <sys/param.h>
41 #include <sys/sysmacros.h>
42 #include <sys/vnode.h>
43 #include <sys/fs/pc_label.h>
44 #include <sys/bootvfs.h>
45 #include <sys/filep.h>
46 #include "pcfilep.h"
47
48 #if defined(_BOOT)
49 #include "../common/util.h"
50 #elif defined(_KERNEL)
51 #include <sys/sunddi.h>
52 #else
53 #include <stdio.h>
54 #include <strings.h>
55 #include <ctype.h>
56 #endif
57
58 #if defined(_BOOT)
59 #define dprintf if (bootrd_debug) printf
60 #elif defined(_KERNEL)
61 #define printf kobj_printf
62 #define dprintf if (bootrd_debug) kobj_printf
63
64 /* PRINTLIKE */
65 extern void kobj_printf(char *, ...);
66 #else
67 #define dprintf if (bootrd_debug) printf
68 #endif
69
70 #define FI_STARTCLUST(fp) (*(ushort_t *)(fp)->fi_buf)
71 #define FI_LENGTH(fp) (*(long *)((fp)->fi_buf + 4))
72
73 extern int bootrd_debug;
74 extern void *bkmem_alloc(size_t);
75 extern void bkmem_free(void *, size_t);
76
77 /*
78 * NOTE: The fileread_callback is set by the calling program
79 * during a file read. diskread_callback is set to fileread_callback
80 * only if reading a file block. It needs to be NULL while reading
81 * cluster blocks.
82 */
83 extern int (*diskread_callback)(int, int);
84 extern int (*fileread_callback)(int, int);
85
86 /*
87 * Local prototypes
88 */
89 static int lookuppn(char *, _dir_entry_p);
90 static fileid_t *find_fp(int);
91 static void *readblock(int, int);
92 static int fat_map(int, int);
93 static int cluster_valid(long, int);
94 static int fat_ctodb(int, int);
95
96 static int bpcfs_mountroot(char *str);
97 static int bpcfs_unmountroot(void);
98 static int bpcfs_open(char *str, int flags);
99 static int bpcfs_close(int fd);
100 static void bpcfs_closeall(void);
101 static ssize_t bpcfs_read(int fdesc, char *buf, size_t count);
102 static off_t bpcfs_lseek(int fdesc, off_t addr, int whence);
103
104 static fileid_t *head;
105 static _fat_controller_p pcfsp;
106
107 /* cache the cluster */
108 static int nsec_cache;
109 static int nsec_start;
110 static char *cluster_cache;
111
112 /*ARGSUSED*/
113 static int
bpcfs_mountroot(char * str)114 bpcfs_mountroot(char *str)
115 {
116 int ncluster;
117 if (pcfsp != NULL)
118 return (0); /* already mounted */
119
120 pcfsp = bkmem_alloc(sizeof (_fat_controller_t));
121 head = (fileid_t *)bkmem_alloc(sizeof (fileid_t));
122 head->fi_back = head->fi_forw = head;
123 head->fi_filedes = 0;
124 head->fi_taken = 0;
125
126 /* read of first floppy sector */
127 head->fi_blocknum = 0;
128 head->fi_count = SECSIZ;
129 head->fi_memp = (caddr_t)pcfsp->f_sector;
130 if (diskread(head)) {
131 printf("failed to read first sector\n");
132 bkmem_free(pcfsp, sizeof (*pcfsp));
133 pcfsp = NULL;
134 return (-1);
135 }
136
137 if (pcfsp->f_bpb.bs_spc == 0) {
138 printf("invalid bios paramet block\n");
139 return (-1);
140 }
141
142 pcfsp->f_rootsec =
143 (pcfsp->f_bpb.bs_num_fats * ltohs(pcfsp->f_bpb.bs_spf)) +
144 ltohs(pcfsp->f_bpb.bs_resv_sectors);
145 pcfsp->f_rootlen =
146 ltohs(pcfsp->f_bpb.bs_num_root_entries) *
147 sizeof (_dir_entry_t) / SECSIZ;
148 pcfsp->f_adjust = 0;
149 pcfsp->f_dclust = CLUSTER_ROOTDIR;
150 pcfsp->f_filesec = pcfsp->f_rootsec + pcfsp->f_rootlen;
151 pcfsp->f_nxtfree = CLUSTER_FIRST;
152
153 /* figure out the number of clusters in this partition */
154 ncluster = (((ulong_t)ltohs(pcfsp->f_bpb.bs_siv) ?
155 (ulong_t)ltohs(pcfsp->f_bpb.bs_siv) :
156 (ulong_t)ltohi(pcfsp->f_bpb.bs_siv)) -
157 pcfsp->f_filesec) / (ulong_t)pcfsp->f_bpb.bs_spc;
158 pcfsp->f_16bit = ncluster >= CLUSTER_MAX_12;
159 pcfsp->f_ncluster = ncluster;
160
161 /* cache the cluster */
162 if (pcfsp->f_16bit)
163 nsec_cache = (((ncluster << 1) + 511) >> 9);
164 else
165 nsec_cache = (ncluster + ((ncluster + 1) >> 1) + 511) >> 9;
166 cluster_cache = bkmem_alloc(nsec_cache * SECSIZ);
167 if (cluster_cache == NULL) {
168 printf("bpcfs_mountroot: out of memory\n");
169 bkmem_free(pcfsp, sizeof (*pcfsp));
170 pcfsp = NULL;
171 return (-1);
172 }
173
174 head->fi_blocknum = nsec_start =
175 ltohs(pcfsp->f_bpb.bs_resv_sectors) + pcfsp->f_adjust;
176 head->fi_count = nsec_cache * SECSIZ;
177 head->fi_memp = cluster_cache;
178 if (diskread(head)) {
179 printf("bpcfs_mountroot: failed to read cluster\n");
180 bkmem_free(pcfsp, sizeof (*pcfsp));
181 pcfsp = NULL;
182 return (-1);
183 }
184 dprintf("read cluster sectors %d starting at %d\n",
185 nsec_cache, nsec_start);
186 return (0);
187 }
188
189 static int
bpcfs_unmountroot(void)190 bpcfs_unmountroot(void)
191 {
192 if (pcfsp == NULL)
193 return (-1);
194
195 (void) bpcfs_closeall();
196
197 return (0);
198 }
199
200 /*
201 * Open a file.
202 */
203 /*ARGSUSED*/
204 int
bpcfs_open(char * str,int flags)205 bpcfs_open(char *str, int flags)
206 {
207 static int filedes = 1;
208
209 fileid_t *filep;
210 _dir_entry_t d;
211
212 dprintf("open %s\n", str);
213 filep = (fileid_t *)bkmem_alloc(sizeof (fileid_t));
214 filep->fi_back = head->fi_back;
215 filep->fi_forw = head;
216 head->fi_back->fi_forw = filep;
217 head->fi_back = filep;
218 filep->fi_filedes = filedes++;
219 filep->fi_taken = 1;
220 filep->fi_path = (char *)bkmem_alloc(strlen(str) + 1);
221 (void) strcpy(filep->fi_path, str);
222
223 if (lookuppn(str, &d)) {
224 (void) bpcfs_close(filep->fi_filedes);
225 return (-1);
226 }
227
228 filep->fi_offset = 0;
229 FI_STARTCLUST(filep) = d.d_cluster;
230 FI_LENGTH(filep) = d.d_size;
231 dprintf("file %s size = %ld\n", str, d.d_size);
232 return (filep->fi_filedes);
233 }
234
235 int
bpcfs_close(int fd)236 bpcfs_close(int fd)
237 {
238 fileid_t *filep;
239
240 dprintf("close %d\n", fd);
241 if (!(filep = find_fp(fd)))
242 return (-1);
243
244 if (filep->fi_taken == 0 || filep == head) {
245 printf("File descripter %d no allocated!\n", fd);
246 return (-1);
247 }
248
249 /* unlink and deallocate node */
250 filep->fi_forw->fi_back = filep->fi_back;
251 filep->fi_back->fi_forw = filep->fi_forw;
252 bkmem_free(filep->fi_path, strlen(filep->fi_path) + 1);
253 bkmem_free((char *)filep, sizeof (fileid_t));
254 dprintf("close done\n");
255 return (0);
256 }
257
258 static void
bpcfs_closeall(void)259 bpcfs_closeall(void)
260 {
261 fileid_t *filep;
262
263 while ((filep = head->fi_forw) != head)
264 if (filep->fi_taken && bpcfs_close(filep->fi_filedes))
265 printf("Filesystem may be inconsistent.\n");
266
267 bkmem_free(pcfsp, sizeof (*pcfsp));
268 bkmem_free(head, sizeof (fileid_t));
269 pcfsp = NULL;
270 head = NULL;
271 }
272
273 static ssize_t
bpcfs_read(int fd,caddr_t b,size_t c)274 bpcfs_read(int fd, caddr_t b, size_t c)
275 {
276 ulong_t sector;
277 uint_t count = 0, xfer, i;
278 char *block;
279 ulong_t off, blk;
280 int rd, spc;
281 fileid_t *fp;
282
283 dprintf("bpcfs_read: fd = %d, buf = %p, size = %d\n",
284 fd, (void *)b, c);
285 fp = find_fp(fd);
286 if (fp == NULL) {
287 printf("invalid file descriptor %d\n", fd);
288 return (-1);
289 }
290
291 spc = pcfsp->f_bpb.bs_spc;
292 off = fp->fi_offset;
293 blk = FI_STARTCLUST(fp);
294 rd = blk == CLUSTER_ROOTDIR ? 1 : 0;
295
296 spc = pcfsp->f_bpb.bs_spc;
297 off = fp->fi_offset;
298 blk = FI_STARTCLUST(fp);
299 rd = (blk == CLUSTER_ROOTDIR) ? 1 : 0;
300
301 if ((c = MIN(FI_LENGTH(fp) - off, c)) == 0)
302 return (0);
303
304 while (off >= pcfsp->f_bpb.bs_spc * SECSIZ) {
305 blk = fat_map(blk, rd);
306 off -= pcfsp->f_bpb.bs_spc * SECSIZ;
307
308 if (!cluster_valid(blk, rd)) {
309 printf("bpcfs_read: invalid cluster: %ld, %d\n",
310 blk, rd);
311 return (-1);
312 }
313 }
314
315 while (count < c) {
316 sector = fat_ctodb(blk, rd);
317 diskread_callback = fileread_callback;
318 for (i = ((off / SECSIZ) % pcfsp->f_bpb.bs_spc); i < spc; i++) {
319 xfer = MIN(SECSIZ - (off % SECSIZ), c - count);
320 if (xfer == 0)
321 break; /* last sector done */
322
323 block = (char *)readblock(sector + i, 1);
324 if (block == NULL) {
325 return (-1);
326 }
327 dprintf("bpcfs_read: read %d bytes\n", xfer);
328 if (diskread_callback == NULL)
329 (void) bcopy(&block[off % SECSIZ], b, xfer);
330 count += xfer;
331 off += xfer;
332 b += xfer;
333 }
334
335 diskread_callback = NULL;
336 if (count < c) {
337 blk = fat_map(blk, rd);
338 if (!cluster_valid(blk, rd)) {
339 printf("bpcfs_read: invalid cluster: %ld, %d\n",
340 blk, rd);
341 break;
342 }
343 }
344 }
345
346 fp->fi_offset += count;
347 return (count);
348 }
349
350 /*
351 * This version of seek() only performs absolute seeks (whence == 0).
352 */
353 static off_t
bpcfs_lseek(int fd,off_t addr,int whence)354 bpcfs_lseek(int fd, off_t addr, int whence)
355 {
356 fileid_t *filep;
357
358 dprintf("lseek %d, off = %lx\n", fd, addr);
359 if (!(filep = find_fp(fd)))
360 return (-1);
361
362 switch (whence) {
363 case SEEK_CUR:
364 filep->fi_offset += addr;
365 break;
366 case SEEK_SET:
367 filep->fi_offset = addr;
368 break;
369 default:
370 case SEEK_END:
371 printf("lseek(): invalid whence value %d\n", whence);
372 break;
373 }
374
375 filep->fi_blocknum = addr / DEV_BSIZE;
376 filep->fi_count = 0;
377 return (0);
378 }
379
380 static fileid_t *
find_fp(int fd)381 find_fp(int fd)
382 {
383 fileid_t *filep = head;
384
385 if (fd >= 0) {
386 while ((filep = filep->fi_forw) != head)
387 if (fd == filep->fi_filedes)
388 return (filep->fi_taken ? filep : 0);
389 }
390
391 return (0);
392 }
393
394 static int
cluster_valid(long c,int rd)395 cluster_valid(long c, int rd)
396 {
397 return ((rd && (c == 0)) ? 1 : (c >= CLUSTER_RES_16_0 ? 0 : c));
398 }
399
400 static int
fat_ctodb(int blk,int r)401 fat_ctodb(int blk, int r)
402 {
403 uint_t s;
404
405 s = r ? blk + pcfsp->f_rootsec + pcfsp->f_adjust :
406 ((blk - 2) * pcfsp->f_bpb.bs_spc) +
407 pcfsp->f_filesec + pcfsp->f_adjust;
408
409 return (s);
410 }
411
412 static int
fat_map(int blk,int rootdir)413 fat_map(int blk, int rootdir)
414 {
415 ulong_t sectn, fat_index;
416 uchar_t *fp;
417
418 if (rootdir) {
419 return (blk > pcfsp->f_rootlen ? CLUSTER_EOF : blk + 1);
420 }
421
422 /* ---- Find out what sector this cluster is in ---- */
423 fat_index = (pcfsp->f_16bit) ? ((ulong_t)blk << 1) :
424 ((ulong_t)blk + ((uint_t)blk >> 1));
425
426 sectn = (fat_index / SECSIZ) + ltohs(pcfsp->f_bpb.bs_resv_sectors)
427 + pcfsp->f_adjust;
428
429 /*
430 * Read two sectors so that if our fat_index points at the last byte
431 * byte we'll have the data needed. This is only a problem for fat12
432 * entries.
433 */
434 if (!(fp = (uchar_t *)readblock(sectn, 2))) {
435 printf("fat_map: bad cluster\n");
436 return (CLUSTER_BAD_16);
437 }
438
439 fp += (fat_index % SECSIZ);
440
441 if (pcfsp->f_16bit)
442 blk = fp[0] | (fp[1] << 8);
443 else {
444 if (blk & 1)
445 blk = ((fp[0] >> 4) & 0xf) | (fp[1] << 4);
446 else
447 blk = ((fp[1] & 0xf) << 8) | fp[0];
448
449 /*
450 * This makes compares easier because we can just compare
451 * against one value instead of two.
452 */
453 if (blk >= CLUSTER_RES_12_0)
454 blk |= CLUSTER_RES_16_0;
455 }
456 return (blk);
457 }
458
459 static int
namecmp(char * pn,char * dn,int cs)460 namecmp(char *pn, char *dn, int cs)
461 {
462 dprintf("namecmp %s, %s, len = %d\n", pn, dn, cs);
463
464 /* starting char must match */
465 while (*pn && *dn) {
466 --cs;
467 if (toupper(*pn++) != toupper(*dn++))
468 return (1);
469 }
470
471 dprintf("namecmp: cs = %d\n", cs);
472 /* remainder should be either ~# or all spaces */
473 if (cs > 0 && *dn == '~')
474 return (0);
475 while (cs > 0) {
476 if (*dn++ != ' ')
477 return (1);
478 --cs;
479 }
480 return (0);
481 }
482
483 static int
dircmp(char * name,char * d_name,char * d_ext)484 dircmp(char *name, char *d_name, char *d_ext)
485 {
486 int ret;
487 char *sep, *ext;
488
489 sep = (char *)strchr(name, '.');
490
491 if (sep) {
492 *sep = '\0';
493 ext = sep + 1;
494 } else
495 ext = " ";
496
497 if (namecmp(name, d_name, NAMESIZ) || namecmp(ext, d_ext, EXTSIZ))
498 ret = 1;
499 else
500 ret = 0;
501 if (sep)
502 *sep = '.';
503 return (ret);
504 }
505
506 static int
lookup(char * n,_dir_entry_p dp,ulong_t dir_blk)507 lookup(char *n, _dir_entry_p dp, ulong_t dir_blk)
508 {
509 int spc = pcfsp->f_bpb.bs_spc;
510 int rd = (dir_blk == CLUSTER_ROOTDIR ? 1 : 0);
511 _dir_entry_p dxp;
512 int j, sector;
513
514 dprintf("lookup: name = %s\n", n);
515
516 while (cluster_valid(dir_blk, rd)) {
517 sector = fat_ctodb(dir_blk, rd);
518 dxp = readblock(sector, 1); /* read one sector */
519 if (dxp == NULL)
520 return (0);
521 for (j = 0; j < DIRENTS * spc; j++, dxp++) {
522 dprintf("lookup: dir entry %s.%s;\n",
523 dxp->d_name, dxp->d_ext);
524 if (dxp->d_name[0] == 0)
525 return (0);
526 if ((uchar_t)dxp->d_name[0] != 0xE5 &&
527 (dxp->d_attr & (DE_LABEL|DE_HIDDEN)) == 0 &&
528 dircmp(n, dxp->d_name, dxp->d_ext) == 0) {
529 dprintf("lookup: match found\n");
530 (void) bcopy(dxp, dp, sizeof (*dp));
531 return (1);
532 }
533 }
534 /* next cluster */
535 dir_blk = fat_map(dir_blk, rd);
536 }
537
538 return (0);
539 }
540
541 static int
lookuppn(char * n,_dir_entry_p dp)542 lookuppn(char *n, _dir_entry_p dp)
543 {
544 long dir_blk;
545 char name[8 + 1 + 3 + 1]; /* <8>.<3>'\0' */
546 char *p, *ep;
547 _dir_entry_t dd;
548
549 dprintf("lookuppn: path = %s\n", n);
550 dir_blk = pcfsp->f_dclust;
551 if ((*n == '\\') || (*n == '/')) {
552 dir_blk = CLUSTER_ROOTDIR;
553 while ((*n == '\\') || (*n == '/'))
554 n++;
555 if (*n == '\0') {
556 (void) bzero(dp, sizeof (*dp));
557 dp->d_cluster = CLUSTER_ROOTDIR;
558 dp->d_attr = DE_DIRECTORY;
559 return (0);
560 }
561 }
562
563 ep = &name[0] + sizeof (name);
564 while (*n) {
565 (void) bzero(name, sizeof (name));
566 p = &name[0];
567 while (*n && (*n != '\\') && (*n != '/'))
568 if (p != ep)
569 *p++ = *n++;
570 else {
571 dprintf("return, name %s is too long\n", name);
572 return (-1); /* name is too long */
573 }
574 while ((*n == '\\') || (*n == '/'))
575 n++;
576 if (lookup(name, &dd, dir_blk) == 0) {
577 dprintf("return, name %s not found\n", name);
578 return (-1);
579 }
580 dprintf("dd = %x:%x:%x attr = %x\n",
581 *(int *)&dd, *(((int *)&dd) + 1),
582 *(((int *)&dd) + 2), dd.d_attr);
583 if (*n && ((dd.d_attr & DE_DIRECTORY) == 0)) {
584 dprintf("return, not a directory\n");
585 return (-1);
586 }
587
588 dir_blk = dd.d_cluster;
589 }
590 (void) bcopy(&dd, dp, sizeof (dd));
591 return (0);
592 }
593
594 static void *
readblock(int sector,int nsec)595 readblock(int sector, int nsec)
596 {
597 if (sector >= nsec_start && sector + nsec <= nsec_start + nsec_cache)
598 return (cluster_cache + (sector - nsec_start) * SECSIZ);
599
600 /* read disk sectors */
601 head->fi_blocknum = sector;
602 head->fi_count = nsec * SECSIZ;
603 head->fi_memp = head->fi_buf;
604 if (diskread(head)) {
605 printf("failed to %d sectors at %d\n", nsec, sector);
606 return (NULL);
607 }
608
609 return (head->fi_buf);
610 }
611
612 struct boot_fs_ops bpcfs_ops = {
613 "boot_pcfs",
614 bpcfs_mountroot,
615 bpcfs_unmountroot,
616 bpcfs_open,
617 bpcfs_close,
618 bpcfs_read,
619 bpcfs_lseek,
620 NULL
621 };
622