source: buchla-68k/orig/IOLIB/BLKWR.C@ 4810254

Last change on this file since 4810254 was 3ae31e9, checked in by Thomas Lopatic <thomas@…>, 8 years ago

Imported original source code.
  • Property mode set to 100755
File size: 5.9 KB
RevLine 
[3ae31e9]1/*
2 =============================================================================
3 blkwr.c -- write a block of 0..32767 sectors
4 Version 14 -- 1987-12-15 -- D.N. Lynx Crowe
5
6 int
7 blkwr(fcp, buf, ns)
8 struct fcb *fcp;
9 char *buf;
10 int ns;
11
12 Writes 'ns' sectors from file 'fcp' into 'buf'.
13 Returns the number of unwritten sectors,
14 or 0 if all were written.
15 =============================================================================
16*/
17
18#define DEBUGIT 0
19
20#include "stddefs.h"
21#include "biosdefs.h"
22#include "errno.h"
23#include "errdefs.h"
24#include "fspars.h"
25
26extern int _nsic(), _alcnew(), _newcls();
27
28extern long _berrno; /* last file system bios error number */
29
30extern struct bpb *_thebpb; /* current bios parameter block */
31
32extern short _thefat[]; /* current file allocation table */
33
34extern short _fatmod; /* FAT modified flag */
35
36#if DEBUGIT
37extern short fsdebug;
38#endif
39
40#if TBUFFER
41
42/* WARNING: this ONLY works for 512 byte sectors, 9 sectors per track */
43
44extern short _b_tbuf[9][256]; /* the track buffer */
45
46extern short _b_trak; /* current track */
47extern short _b_side; /* current side */
48extern short _b_sect; /* current sector */
49extern short _b_tsec; /* base sector for current track */
50
51#endif
52
53/*
54
55*/
56
57#if TBUFFER
58
59/*
60 =============================================================================
61 _secwr(buf, rec) -- write a logical sector into the track buffer
62 =============================================================================
63*/
64
65long
66_secwr(buf, rec)
67register char *buf;
68register short rec;
69{
70 register short track, side, sector;
71
72 if (_thebpb->dspt NE 9) /* make sure we can do this */
73 return(ERR07);
74
75 if (_thebpb->recsiz NE 512)
76 return(ERR07);
77
78 track = rec / _thebpb->dspc; /* desired track */
79 sector = rec - (track * _thebpb->dspc); /* logical sector */
80
81 if (sector GE _thebpb->dspt) { /* adjust sector and side */
82
83 sector -= _thebpb->dspt;
84 side = 1;
85
86 } else {
87
88 side = 0;
89 }
90
91#if DEBUGIT
92 if (fsdebug) {
93
94 printf("_secwr($%08.8LX, %d): track=%d, side=%d, sector=%d\n",
95 buf, rec, track, side, sector);
96 printf("_secwr(): _b_trak=%d, _b_side=%d, _b_sect=%d, _b_tsec=%d\n",
97 _b_trak, _b_side, _b_sect, _b_tsec);
98 }
99#endif
100
101 if ((track NE _b_trak) OR (side NE _b_side)) /* track in buffer ? */
102 return(0L);
103
104 memcpy((char *)_b_tbuf[sector], buf, 512); /* update the buffer */
105
106#if DEBUGIT
107 if (fsdebug)
108 printf("_secwr(): updated track buffer\n");
109#endif
110
111 return(0L);
112}
113
114#endif
115
116/*
117
118*/
119
120/*
121 =============================================================================
122 blkwr(fcp, buf, ns) -- write 'ns' sectors from file 'fcp' into 'buf'.
123 Returns the number of unwritten sectors, or 0 if all were written.
124 =============================================================================
125*/
126
127int
128blkwr(fcp, buf, ns)
129struct fcb *fcp;
130char *buf;
131int ns;
132{
133 long rc;
134 short clustr;
135
136 while (ns > 0) { /* write a sector at a time */
137
138 if (fcp->asects) {
139
140 if (fcp->curlsn LT fcp->asects) {
141
142#if DEBUGIT
143 if (fsdebug)
144 printf("blkwr(): [1] ns=%d, curlsn=%ld, curdsn=%ld, curcls=%u, buf=$%08lX\n",
145 ns, fcp->curlsn, fcp->curdsn, fcp->curcls, buf);
146#endif
147
148 if (rc = BIOS(B_RDWR, 1, buf, 1, (short)fcp->curdsn, 0)) {
149
150#if DEBUGIT
151 if (fsdebug)
152 printf("blkwr(): B_RDWR failed, rc=%ld\n", rc);
153#endif
154
155 _berrno = rc; /* log the error */
156 errno = EIO;
157 return(ns); /* return unwritten sector count */
158 }
159
160#if TBUFFER
161 _secwr(buf, (short)fcp->curdsn);
162#endif
163
164 rc = _nsic(fcp, _thebpb, _thefat);
165
166#if DEBUGIT
167 if (fsdebug)
168 printf("blkwr(): _nsic() rc=%ld\n", rc);
169#endif
170
171 if (--ns EQ 0) /* done if no more to do */
172 return(0);
173
174 if (rc < 0) { /* bad cluster ? */
175
176 errno = EIO; /* set error number */
177 return(ns); /* return unwritten sector count */
178 }
179
180 buf += _thebpb->recsiz;
181/*
182
183*/
184 } else if (fcp->curlsn EQ fcp->asects) {
185
186 if (_alcnew(fcp)) { /* allocate a cluster */
187
188 errno = EIO; /* set error number */
189 return(ns); /* return unwritten sector count */
190 }
191
192 fcp->modefl &= ~FC_EOF; /* clear EOF flag */
193
194#if DEBUGIT
195 if (fsdebug)
196 printf("blkwr(): [2] ns=%d, curlsn=%ld, curdsn=%ld, curcls=%u, buf=$%08lX\n",
197 ns, fcp->curlsn, fcp->curdsn, fcp->curcls, buf);
198#endif
199
200 if (rc = BIOS(B_RDWR, 1, buf, 1, (short)fcp->curdsn, 0)) {
201
202#if DEBUGIT
203 if (fsdebug)
204 printf("blkwr(): B_RDWR failed, rc=%ld\n", rc);
205#endif
206
207 _berrno = rc; /* log the error */
208 errno = EIO;
209 return(ns); /* return unwritten sector count */
210 }
211
212#if TBUFFER
213 _secwr(buf, (short)fcp->curdsn);
214#endif
215
216 ++fcp->curlsn;
217 ++fcp->clsec;
218 ++fcp->curdsn;
219
220 if (--ns EQ 0)
221 return(0);
222
223 buf += _thebpb->recsiz; /* advance buffer pointer */
224 }
225/*
226
227*/
228 } else {
229
230 if (0 EQ (clustr = _newcls())) {
231
232 errno = EIO;
233 return(ns);
234 }
235
236 fcp->de.bclust = micons(clustr);
237 _ptcl12(_thefat, clustr, 0x0FF8);
238 _fatmod = TRUE;
239 fcp->curdsn = _cl2lsn(_thebpb, clustr);
240 fcp->curcls = clustr;
241 fcp->clsec = 0;
242 fcp->asects = _thebpb->clsiz;
243 fcp->modefl &= ~FC_EOF;
244
245 fcp->modefl &= ~FC_EOF; /* clear EOF flag */
246
247#if DEBUGIT
248 if (fsdebug)
249 printf("blkwr(): [3] ns=%d, curlsn=%ld, curdsn=%ld, curcls=%u, buf=$%08lX\n",
250 ns, fcp->curlsn, fcp->curdsn, fcp->curcls, buf);
251#endif
252
253 if (rc = BIOS(B_RDWR, 1, buf, 1, (short)fcp->curdsn, 0)) {
254
255#if DEBUGIT
256 if (fsdebug)
257 printf("blkwr(): B_RDWR failed, rc=%ld\n", rc);
258#endif
259
260 _berrno = rc; /* log the error */
261 errno = EIO;
262 return(ns); /* return unwritten sector count */
263 }
264
265#if TBUFFER
266 _secwr(buf, (short)fcp->curdsn);
267#endif
268
269 ++fcp->curlsn;
270 ++fcp->clsec;
271 ++fcp->curdsn;
272
273 if (--ns EQ 0)
274 return(0);
275
276 buf += _thebpb->recsiz; /* advance buffer pointer */
277 }
278 }
279
280 return(ns); /* return (will be zero or negative) */
281}
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