2 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
3 * Copyright (c) 2001 John H. Baldwin <jhb@FreeBSD.org>
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
32 * BIOS CD device handling for CD's that have been booted off of via no
33 * emulation booting as defined in the El Torito standard.
35 * Ideas and algorithms from:
37 * - FreeBSD libi386/biosdisk.c
43 #include <sys/param.h>
44 #include <machine/bootinfo.h>
48 #include <bootstrap.h>
53 #define BIOSCD_SECSIZE 2048
54 #define BUFSIZE (1 * BIOSCD_SECSIZE)
57 /* Major numbers for devices we frontend for. */
62 # define DEBUG(fmt, args...) printf("%s: " fmt "\n" , __func__ , ## args)
64 # define DEBUG(fmt, args...)
67 struct specification_packet {
73 u_short sp_devicespec;
74 u_short sp_buffersegment;
75 u_short sp_loadsegment;
76 u_short sp_sectorcount;
82 * List of BIOS devices, translation from disk unit number to
85 static struct bcinfo {
86 int bc_unit; /* BIOS unit number */
87 struct specification_packet bc_sp;
88 int bc_open; /* reference counter */
89 void *bc_bcache; /* buffer cache data */
91 static int nbcinfo = 0;
93 #define BC(dev) (bcinfo[(dev)->d_unit])
95 static int bc_read(int unit, daddr_t dblk, int blks, caddr_t dest);
96 static int bc_init(void);
97 static int bc_strategy(void *devdata, int flag, daddr_t dblk,
98 size_t size, char *buf, size_t *rsize);
99 static int bc_realstrategy(void *devdata, int flag, daddr_t dblk,
100 size_t size, char *buf, size_t *rsize);
101 static int bc_open(struct open_file *f, ...);
102 static int bc_close(struct open_file *f);
103 static int bc_print(int verbose);
105 struct devsw bioscd = {
118 * Translate between BIOS device numbers and our private unit numbers.
121 bc_bios2unit(int biosdev)
125 DEBUG("looking for bios device 0x%x", biosdev);
126 for (i = 0; i < nbcinfo; i++) {
127 DEBUG("bc unit %d is BIOS device 0x%x", i, bcinfo[i].bc_unit);
128 if (bcinfo[i].bc_unit == biosdev)
135 bc_unit2bios(int unit)
137 if ((unit >= 0) && (unit < nbcinfo))
138 return(bcinfo[unit].bc_unit);
143 * We can't quiz, we have to be told what device to use, so this functoin
144 * doesn't do anything. Instead, the loader calls bc_add() with the BIOS
145 * device number to add.
158 if (nbcinfo >= MAXBCDEV)
160 bcinfo[nbcinfo].bc_unit = biosdev;
165 v86.ds = VTOPSEG(&bcinfo[nbcinfo].bc_sp);
166 v86.esi = VTOPOFF(&bcinfo[nbcinfo].bc_sp);
168 if ((v86.eax & 0xff00) != 0)
171 printf("BIOS CD is cd%d\n", nbcinfo);
173 bcache_add_dev(nbcinfo); /* register cd device in bcache */
178 * Print information about disks
181 bc_print(int verbose)
189 printf("%s devices:", bioscd.dv_name);
190 if ((ret = pager_output("\n")) != 0)
193 for (i = 0; i < nbcinfo; i++) {
194 snprintf(line, sizeof(line), " cd%d: Device 0x%x\n", i,
195 bcinfo[i].bc_sp.sp_devicespec);
196 if ((ret = pager_output(line)) != 0)
203 * Attempt to open the disk described by (dev) for use by (f).
206 bc_open(struct open_file *f, ...)
209 struct i386_devdesc *dev;
212 dev = va_arg(ap, struct i386_devdesc *);
214 if (dev->d_unit >= nbcinfo) {
215 DEBUG("attempt to open nonexistent disk");
220 if (BC(dev).bc_bcache == NULL)
221 BC(dev).bc_bcache = bcache_allocate();
226 bc_close(struct open_file *f)
228 struct i386_devdesc *dev;
230 dev = (struct i386_devdesc *)f->f_devdata;
232 if (BC(dev).bc_open == 0) {
233 bcache_free(BC(dev).bc_bcache);
234 BC(dev).bc_bcache = NULL;
240 bc_strategy(void *devdata, int rw, daddr_t dblk, size_t size,
241 char *buf, size_t *rsize)
243 struct bcache_devdata bcd;
244 struct i386_devdesc *dev;
246 dev = (struct i386_devdesc *)devdata;
247 bcd.dv_strategy = bc_realstrategy;
248 bcd.dv_devdata = devdata;
249 bcd.dv_cache = BC(dev).bc_bcache;
251 return (bcache_strategy(&bcd, rw, dblk, size, buf, rsize));
255 bc_realstrategy(void *devdata, int rw, daddr_t dblk, size_t size,
256 char *buf, size_t *rsize)
258 struct i386_devdesc *dev;
261 #ifdef BD_SUPPORT_FRAGS
262 char fragbuf[BIOSCD_SECSIZE];
265 fragsize = size % BIOSCD_SECSIZE;
267 if (size % BIOSCD_SECSIZE)
271 if ((rw & F_MASK) != F_READ)
273 dev = (struct i386_devdesc *)devdata;
275 blks = size / BIOSCD_SECSIZE;
276 if (dblk % (BIOSCD_SECSIZE / DEV_BSIZE) != 0)
278 dblk /= (BIOSCD_SECSIZE / DEV_BSIZE);
279 DEBUG("read %d from %lld to %p", blks, dblk, buf);
283 if ((blks = bc_read(unit, dblk, blks, buf)) < 0) {
287 if (size / BIOSCD_SECSIZE > blks) {
289 *rsize = blks * BIOSCD_SECSIZE;
293 #ifdef BD_SUPPORT_FRAGS
294 DEBUG("frag read %d from %lld+%d to %p",
295 fragsize, dblk, blks, buf + (blks * BIOSCD_SECSIZE));
296 if (fragsize && bc_read(unit, dblk + blks, 1, fragbuf) != 1) {
299 *rsize = blks * BIOSCD_SECSIZE;
302 DEBUG("frag read error");
305 bcopy(fragbuf, buf + (blks * BIOSCD_SECSIZE), fragsize);
312 /* return negative value for an error, otherwise blocks read */
314 bc_read(int unit, daddr_t dblk, int blks, caddr_t dest)
316 u_int maxfer, resid, result, retry, x;
318 static struct edd_packet packet;
324 /* Just in case some idiot actually tries to read -1 blocks... */
328 /* If nothing to do, just return succcess. */
332 /* Decide whether we have to bounce */
333 if (VTOP(dest) >> 20 != 0) {
335 * The destination buffer is above first 1MB of
336 * physical memory so we have to arrange a suitable
339 x = V86_IO_BUFFER_SIZE / BIOSCD_SECSIZE;
340 x = min(x, (unsigned)blks);
341 bbuf = PTOV(V86_IO_BUFFER);
348 biosdev = bc_unit2bios(unit);
362 * Loop retrying the operation a couple of times. The BIOS
365 for (retry = 0; retry < 3; retry++) {
366 /* If retrying, reset the drive */
375 packet.len = sizeof(struct edd_packet);
377 packet.off = VTOPOFF(xp);
378 packet.seg = VTOPSEG(xp);
384 v86.ds = VTOPSEG(&packet);
385 v86.esi = VTOPOFF(&packet);
387 result = V86_CY(v86.efl);
390 /* fall back to 1 sector read */
395 error = (v86.eax >> 8) & 0xff;
397 DEBUG("%d sectors from %lld to %p (0x%x) %s", x, dblk, p,
398 VTOP(p), result ? "failed" : "ok");
399 DEBUG("unit %d status 0x%x", unit, error);
401 /* still an error? break off */
406 bcopy(bbuf, p, x * BIOSCD_SECSIZE);
407 p += (x * BIOSCD_SECSIZE);
412 /* hexdump(dest, (blks * BIOSCD_SECSIZE)); */
414 if (blks - resid == 0)
415 return (-1); /* read failed */
417 return (blks - resid);
421 * Return a suitable dev_t value for (dev).
424 bc_getdev(struct i386_devdesc *dev)
431 biosdev = bc_unit2bios(unit);
432 DEBUG("unit %d BIOS device %d", unit, biosdev);
433 if (biosdev == -1) /* not a BIOS device */
437 * XXX: Need to examine device spec here to figure out if SCSI or
438 * ATAPI. No idea on how to figure out device number. All we can
439 * really pass to the kernel is what bus and device on which bus we
440 * were booted from, which dev_t isn't well suited to since those
441 * number don't match to unit numbers very well. We may just need
442 * to engage in a hack where we pass -C to the boot args if we are
448 /* XXX: Assume partition 'a'. */
449 rootdev = MAKEBOOTDEV(major, 0, unit, 0);
450 DEBUG("dev is 0x%x\n", rootdev);