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>
45 #include <machine/psl.h>
49 #include <bootstrap.h>
54 #define BIOSCD_SECSIZE 2048
55 #define BUFSIZE (1 * BIOSCD_SECSIZE)
58 /* Major numbers for devices we frontend for. */
63 # define DEBUG(fmt, args...) printf("%s: " fmt "\n" , __func__ , ## args)
65 # define DEBUG(fmt, args...)
68 struct specification_packet {
74 u_short sp_devicespec;
75 u_short sp_buffersegment;
76 u_short sp_loadsegment;
77 u_short sp_sectorcount;
83 * List of BIOS devices, translation from disk unit number to
86 static struct bcinfo {
87 int bc_unit; /* BIOS unit number */
88 struct specification_packet bc_sp;
90 static int nbcinfo = 0;
92 static int bc_read(int unit, daddr_t dblk, int blks, caddr_t dest);
93 static int bc_init(void);
94 static int bc_strategy(void *devdata, int flag, daddr_t dblk,
95 size_t size, char *buf, size_t *rsize);
96 static int bc_open(struct open_file *f, ...);
97 static int bc_close(struct open_file *f);
98 static void bc_print(int verbose);
100 struct devsw bioscd = {
113 * Translate between BIOS device numbers and our private unit numbers.
116 bc_bios2unit(int biosdev)
120 DEBUG("looking for bios device 0x%x", biosdev);
121 printf("looking for bios device 0x%x, nbcinfo=%d\n", biosdev, nbcinfo);
122 for (i = 0; i < nbcinfo; i++) {
123 DEBUG("bc unit %d is BIOS device 0x%x", i, bcinfo[i].bc_unit);
124 if (bcinfo[i].bc_unit == biosdev)
131 bc_unit2bios(int unit)
133 if ((unit >= 0) && (unit < nbcinfo))
134 return(bcinfo[unit].bc_unit);
139 * We can't quiz, we have to be told what device to use, so this functoin
140 * doesn't do anything. Instead, the loader calls bc_add() with the BIOS
141 * device number to add.
153 printf("bc_add(%d)\n", biosdev);
155 if (nbcinfo >= MAXBCDEV)
157 bcinfo[nbcinfo].bc_unit = biosdev;
162 v86.ds = VTOPSEG(&bcinfo[nbcinfo].bc_sp);
163 v86.esi = VTOPOFF(&bcinfo[nbcinfo].bc_sp);
165 if ((v86.eax & 0xff00) != 0) {
166 printf("CD probe failed, eax=0x%08x\n", v86.eax);
170 printf("BIOS CD is cd%d\n", nbcinfo);
176 * Print information about disks
179 bc_print(int verbose)
184 for (i = 0; i < nbcinfo; i++) {
185 sprintf(line, " cd%d: Device 0x%x\n", i,
186 bcinfo[i].bc_sp.sp_devicespec);
192 * Attempt to open the disk described by (dev) for use by (f).
195 bc_open(struct open_file *f, ...)
198 struct i386_devdesc *dev;
201 dev = va_arg(ap, struct i386_devdesc *);
203 if (dev->d_unit >= nbcinfo) {
204 DEBUG("attempt to open nonexistent disk");
212 bc_close(struct open_file *f)
219 bc_strategy(void *devdata, int rw, daddr_t dblk, size_t size, char *buf,
222 struct i386_devdesc *dev;
225 #ifdef BD_SUPPORT_FRAGS
226 char fragbuf[BIOSCD_SECSIZE];
229 fragsize = size % BIOSCD_SECSIZE;
231 if (size % BIOSCD_SECSIZE)
237 dev = (struct i386_devdesc *)devdata;
239 blks = size / BIOSCD_SECSIZE;
240 if (dblk % (BIOSCD_SECSIZE / DEV_BSIZE) != 0)
242 dblk /= (BIOSCD_SECSIZE / DEV_BSIZE);
243 DEBUG("read %d from %lld to %p", blks, dblk, buf);
247 if (blks && bc_read(unit, dblk, blks, buf)) {
251 #ifdef BD_SUPPORT_FRAGS
252 DEBUG("frag read %d from %lld+%d to %p",
253 fragsize, dblk, blks, buf + (blks * BIOSCD_SECSIZE));
254 if (fragsize && bc_read(unit, dblk + blks, 1, fragbuf)) {
255 DEBUG("frag read error");
258 bcopy(fragbuf, buf + (blks * BIOSCD_SECSIZE), fragsize);
265 /* Max number of sectors to bounce-buffer at a time. */
266 #define CD_BOUNCEBUF 8
269 bc_read(int unit, daddr_t dblk, int blks, caddr_t dest)
271 u_int maxfer, resid, result, retry, x;
273 static struct edd_packet packet;
279 /* Just in case some idiot actually tries to read -1 blocks... */
283 /* If nothing to do, just return succcess. */
287 /* Decide whether we have to bounce */
288 if (VTOP(dest) >> 20 != 0) {
290 * The destination buffer is above first 1MB of
291 * physical memory so we have to arrange a suitable
294 x = min(CD_BOUNCEBUF, (unsigned)blks);
295 bbuf = alloca(x * BIOSCD_SECSIZE);
302 biosdev = bc_unit2bios(unit);
316 * Loop retrying the operation a couple of times. The BIOS
319 for (retry = 0; retry < 3; retry++) {
320 /* If retrying, reset the drive */
329 packet.len = sizeof(struct edd_packet);
331 packet.off = VTOPOFF(xp);
332 packet.seg = VTOPSEG(xp);
338 v86.ds = VTOPSEG(&packet);
339 v86.esi = VTOPOFF(&packet);
341 result = (v86.efl & PSL_C);
347 error = (v86.eax >> 8) & 0xff;
349 DEBUG("%d sectors from %lld to %p (0x%x) %s", x, dblk, p,
350 VTOP(p), result ? "failed" : "ok");
351 DEBUG("unit %d status 0x%x", unit, error);
353 bcopy(bbuf, p, x * BIOSCD_SECSIZE);
354 p += (x * BIOSCD_SECSIZE);
359 /* hexdump(dest, (blks * BIOSCD_SECSIZE)); */
364 * Return a suitable dev_t value for (dev).
367 bc_getdev(struct i386_devdesc *dev)
374 biosdev = bc_unit2bios(unit);
375 DEBUG("unit %d BIOS device %d", unit, biosdev);
376 if (biosdev == -1) /* not a BIOS device */
380 * XXX: Need to examine device spec here to figure out if SCSI or
381 * ATAPI. No idea on how to figure out device number. All we can
382 * really pass to the kernel is what bus and device on which bus we
383 * were booted from, which dev_t isn't well suited to since those
384 * number don't match to unit numbers very well. We may just need
385 * to engage in a hack where we pass -C to the boot args if we are
391 /* XXX: Assume partition 'a'. */
392 rootdev = MAKEBOOTDEV(major, 0, unit, 0);
393 DEBUG("dev is 0x%x\n", rootdev);