1/*
2 *  GRUB  --  GRand Unified Bootloader
3 *  Copyright (C) 2000, 2001  Free Software Foundation, Inc.
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 2 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, write to the Free Software
17 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
18 */
19
20/*
21 * Elements of this file were originally from the FreeBSD "biosboot"
22 * bootloader file "disk.c" dated 4/12/95.
23 *
24 * The license and header comments from that file are included here.
25 */
26
27/*
28 * Mach Operating System
29 * Copyright (c) 1992, 1991 Carnegie Mellon University
30 * All Rights Reserved.
31 *
32 * Permission to use, copy, modify and distribute this software and its
33 * documentation is hereby granted, provided that both the copyright
34 * notice and this permission notice appear in all copies of the
35 * software, derivative works or modified versions, and any portions
36 * thereof, and that both notices appear in supporting documentation.
37 *
38 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
39 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
40 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
41 *
42 * Carnegie Mellon requests users of this software to return to
43 *
44 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
45 *  School of Computer Science
46 *  Carnegie Mellon University
47 *  Pittsburgh PA 15213-3890
48 *
49 * any improvements or extensions that they make and grant Carnegie Mellon
50 * the rights to redistribute these changes.
51 *
52 *	from: Mach, Revision 2.2  92/04/04  11:35:49  rpd
53 *	$Id: fsys_ffs.c,v 1.10 2001/11/12 06:57:29 okuji Exp $
54 */
55
56#ifdef FSYS_FFS
57
58#include "shared.h"
59
60#include "filesys.h"
61
62#include "defs.h"
63#include "disk_inode.h"
64#include "disk_inode_ffs.h"
65#include "dir.h"
66#include "fs.h"
67
68/* used for filesystem map blocks */
69static int mapblock;
70static int mapblock_offset;
71static int mapblock_bsize;
72
73/* pointer to superblock */
74#define SUPERBLOCK ((struct fs *) ( FSYS_BUF + 8192 ))
75#define INODE ((struct icommon *) ( FSYS_BUF + 16384 ))
76#define MAPBUF ( FSYS_BUF + 24576 )
77#define MAPBUF_LEN 8192
78
79
80int
81ffs_mount (void)
82{
83  int retval = 1;
84
85  if ((((current_drive & 0x80) || (current_slice != 0))
86       && ! IS_PC_SLICE_TYPE_BSD_WITH_FS (current_slice, FS_BSDFFS))
87      || part_length < (SBLOCK + (SBSIZE / DEV_BSIZE))
88      || !devread (SBLOCK, 0, SBSIZE, (char *) SUPERBLOCK)
89      || SUPERBLOCK->fs_magic != FS_MAGIC)
90    retval = 0;
91
92  mapblock = -1;
93  mapblock_offset = -1;
94
95  return retval;
96}
97
98static int
99block_map (int file_block)
100{
101  int bnum, offset, bsize;
102
103  if (file_block < NDADDR)
104    return (INODE->i_db[file_block]);
105
106  /* If the blockmap loaded does not include FILE_BLOCK,
107     load a new blockmap.  */
108  if ((bnum = fsbtodb (SUPERBLOCK, INODE->i_ib[0])) != mapblock
109      || (mapblock_offset <= bnum && bnum <= mapblock_offset + mapblock_bsize))
110    {
111      if (MAPBUF_LEN < SUPERBLOCK->fs_bsize)
112	{
113	  offset = ((file_block - NDADDR) % NINDIR (SUPERBLOCK));
114	  bsize = MAPBUF_LEN;
115
116	  if (offset + MAPBUF_LEN > SUPERBLOCK->fs_bsize)
117	    offset = (SUPERBLOCK->fs_bsize - MAPBUF_LEN) / sizeof (int);
118	}
119      else
120	{
121	  bsize = SUPERBLOCK->fs_bsize;
122	  offset = 0;
123	}
124
125      if (! devread (bnum, offset * sizeof (int), bsize, (char *) MAPBUF))
126	{
127	  mapblock = -1;
128	  mapblock_bsize = -1;
129	  mapblock_offset = -1;
130	  errnum = ERR_FSYS_CORRUPT;
131	  return -1;
132	}
133
134      mapblock = bnum;
135      mapblock_bsize = bsize;
136      mapblock_offset = offset;
137    }
138
139  return (((int *) MAPBUF)[((file_block - NDADDR) % NINDIR (SUPERBLOCK))
140			  - mapblock_offset]);
141}
142
143
144int
145ffs_read (char *buf, int len)
146{
147  int logno, off, size, map, ret = 0;
148
149  while (len && !errnum)
150    {
151      off = blkoff (SUPERBLOCK, filepos);
152      logno = lblkno (SUPERBLOCK, filepos);
153      size = blksize (SUPERBLOCK, INODE, logno);
154
155      if ((map = block_map (logno)) < 0)
156	break;
157
158      size -= off;
159
160      if (size > len)
161	size = len;
162
163      disk_read_func = disk_read_hook;
164
165      devread (fsbtodb (SUPERBLOCK, map), off, size, buf);
166
167      disk_read_func = NULL;
168
169      buf += size;
170      len -= size;
171      filepos += size;
172      ret += size;
173    }
174
175  if (errnum)
176    ret = 0;
177
178  return ret;
179}
180
181
182int
183ffs_dir (char *dirname)
184{
185  char *rest, ch;
186  int block, off, loc, map, ino = ROOTINO;
187  struct direct *dp;
188
189/* main loop to find destination inode */
190loop:
191
192  /* load current inode (defaults to the root inode) */
193
194	if (!devread (fsbtodb (SUPERBLOCK, itod (SUPERBLOCK, ino)),
195								ino % (SUPERBLOCK->fs_inopb) * sizeof (struct dinode),
196								sizeof (struct dinode), (char *) INODE))
197			return 0;			/* XXX what return value? */
198
199  /* if we have a real file (and we're not just printing possibilities),
200     then this is where we want to exit */
201
202  if (!*dirname || isspace (*dirname))
203    {
204      if ((INODE->i_mode & IFMT) != IFREG)
205	{
206	  errnum = ERR_BAD_FILETYPE;
207	  return 0;
208	}
209
210      filemax = INODE->i_size;
211
212      /* incomplete implementation requires this! */
213      fsmax = (NDADDR + NINDIR (SUPERBLOCK)) * SUPERBLOCK->fs_bsize;
214      return 1;
215    }
216
217  /* continue with file/directory name interpretation */
218
219  while (*dirname == '/')
220    dirname++;
221
222  if (!(INODE->i_size) || ((INODE->i_mode & IFMT) != IFDIR))
223    {
224      errnum = ERR_BAD_FILETYPE;
225      return 0;
226    }
227
228  for (rest = dirname; (ch = *rest) && !isspace (ch) && ch != '/'; rest++);
229
230  *rest = 0;
231  loc = 0;
232
233  /* loop for reading a the entries in a directory */
234
235  do
236    {
237      if (loc >= INODE->i_size)
238	{
239#if 0
240	  putchar ('\n');
241#endif
242
243	  if (print_possibilities < 0)
244	    return 1;
245
246	  errnum = ERR_FILE_NOT_FOUND;
247	  *rest = ch;
248	  return 0;
249	}
250
251      if (!(off = blkoff (SUPERBLOCK, loc)))
252	{
253	  block = lblkno (SUPERBLOCK, loc);
254
255	  if ((map = block_map (block)) < 0
256	      || !devread (fsbtodb (SUPERBLOCK, map), 0,
257			   blksize (SUPERBLOCK, INODE, block),
258			   (char *) FSYS_BUF))
259	    {
260	      errnum = ERR_FSYS_CORRUPT;
261	      *rest = ch;
262	      return 0;
263	    }
264	}
265
266      dp = (struct direct *) (FSYS_BUF + off);
267      loc += dp->d_reclen;
268
269#ifndef STAGE1_5
270      if (dp->d_ino && print_possibilities && ch != '/'
271	  && (!*dirname || substring (dirname, dp->d_name) <= 0))
272	{
273	  if (print_possibilities > 0)
274	    print_possibilities = -print_possibilities;
275
276	  print_a_completion (dp->d_name);
277	}
278#endif /* STAGE1_5 */
279    }
280  while (!dp->d_ino || (substring (dirname, dp->d_name) != 0
281			|| (print_possibilities && ch != '/')));
282
283  /* only get here if we have a matching directory entry */
284
285  ino = dp->d_ino;
286  *(dirname = rest) = ch;
287
288  /* go back to main loop at top of function */
289  goto loop;
290}
291
292int
293ffs_embed (int *start_sector, int needed_sectors)
294{
295  /* XXX: I don't know if this is really correct. Someone who is
296     familiar with BSD should check for this.  */
297  if (needed_sectors > 14)
298    return 0;
299
300  *start_sector = 1;
301#if 1
302  /* FIXME: Disable the embedding in FFS until someone checks if
303     the code above is correct.  */
304  return 0;
305#else
306  return 1;
307#endif
308}
309
310#endif /* FSYS_FFS */
311