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>
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;
89 static int nbcinfo = 0;
91 static int bc_read(int unit, daddr_t dblk, int blks, caddr_t dest);
92 static int bc_init(void);
93 static int bc_strategy(void *devdata, int flag, daddr_t dblk,
94 size_t size, char *buf, size_t *rsize);
95 static int bc_open(struct open_file *f, ...);
96 static int bc_close(struct open_file *f);
97 static void bc_print(int verbose);
99 struct devsw bioscd = {
112 * Translate between BIOS device numbers and our private unit numbers.
115 bc_bios2unit(int biosdev)
119 DEBUG("looking for bios device 0x%x", biosdev);
120 printf("looking for bios device 0x%x, nbcinfo=%d\n", biosdev, nbcinfo);
121 for (i = 0; i < nbcinfo; i++) {
122 DEBUG("bc unit %d is BIOS device 0x%x", i, bcinfo[i].bc_unit);
123 if (bcinfo[i].bc_unit == biosdev)
130 bc_unit2bios(int unit)
132 if ((unit >= 0) && (unit < nbcinfo))
133 return(bcinfo[unit].bc_unit);
138 * We can't quiz, we have to be told what device to use, so this functoin
139 * doesn't do anything. Instead, the loader calls bc_add() with the BIOS
140 * device number to add.
152 printf("bc_add(%d)\n", biosdev);
154 if (nbcinfo >= MAXBCDEV)
156 bcinfo[nbcinfo].bc_unit = biosdev;
161 v86.ds = VTOPSEG(&bcinfo[nbcinfo].bc_sp);
162 v86.esi = VTOPOFF(&bcinfo[nbcinfo].bc_sp);
164 if ((v86.eax & 0xff00) != 0) {
165 printf("CD probe failed, eax=0x%08x\n", v86.eax);
169 printf("BIOS CD is cd%d\n", nbcinfo);
175 * Print information about disks
178 bc_print(int verbose)
183 for (i = 0; i < nbcinfo; i++) {
184 sprintf(line, " cd%d: Device 0x%x\n", i,
185 bcinfo[i].bc_sp.sp_devicespec);
191 * Attempt to open the disk described by (dev) for use by (f).
194 bc_open(struct open_file *f, ...)
197 struct i386_devdesc *dev;
200 dev = va_arg(ap, struct i386_devdesc *);
202 if (dev->d_unit >= nbcinfo) {
203 DEBUG("attempt to open nonexistent disk");
211 bc_close(struct open_file *f)
218 bc_strategy(void *devdata, int rw, daddr_t dblk, size_t size, char *buf,
221 struct i386_devdesc *dev;
224 #ifdef BD_SUPPORT_FRAGS
225 char fragbuf[BIOSCD_SECSIZE];
228 fragsize = size % BIOSCD_SECSIZE;
230 if (size % BIOSCD_SECSIZE)
236 dev = (struct i386_devdesc *)devdata;
238 blks = size / BIOSCD_SECSIZE;
239 if (dblk % (BIOSCD_SECSIZE / DEV_BSIZE) != 0)
241 dblk /= (BIOSCD_SECSIZE / DEV_BSIZE);
242 DEBUG("read %d from %lld to %p", blks, dblk, buf);
246 if (blks && bc_read(unit, dblk, blks, buf)) {
250 #ifdef BD_SUPPORT_FRAGS
251 DEBUG("frag read %d from %lld+%d to %p",
252 fragsize, dblk, blks, buf + (blks * BIOSCD_SECSIZE));
253 if (fragsize && bc_read(unit, dblk + blks, 1, fragbuf)) {
254 DEBUG("frag read error");
257 bcopy(fragbuf, buf + (blks * BIOSCD_SECSIZE), fragsize);
264 /* Max number of sectors to bounce-buffer at a time. */
265 #define CD_BOUNCEBUF 8
268 bc_read(int unit, daddr_t dblk, int blks, caddr_t dest)
270 u_int maxfer, resid, result, retry, x;
272 static struct edd_packet packet;
278 /* Just in case some idiot actually tries to read -1 blocks... */
282 /* If nothing to do, just return succcess. */
286 /* Decide whether we have to bounce */
287 if (VTOP(dest) >> 20 != 0) {
289 * The destination buffer is above first 1MB of
290 * physical memory so we have to arrange a suitable
293 x = min(CD_BOUNCEBUF, (unsigned)blks);
294 bbuf = alloca(x * BIOSCD_SECSIZE);
301 biosdev = bc_unit2bios(unit);
315 * Loop retrying the operation a couple of times. The BIOS
318 for (retry = 0; retry < 3; retry++) {
319 /* If retrying, reset the drive */
330 packet.offset = VTOPOFF(xp);
331 packet.seg = VTOPSEG(xp);
337 v86.ds = VTOPSEG(&packet);
338 v86.esi = VTOPOFF(&packet);
340 result = (v86.efl & PSL_C);
346 error = (v86.eax >> 8) & 0xff;
348 DEBUG("%d sectors from %lld to %p (0x%x) %s", x, dblk, p,
349 VTOP(p), result ? "failed" : "ok");
350 DEBUG("unit %d status 0x%x", unit, error);
352 bcopy(bbuf, p, x * BIOSCD_SECSIZE);
353 p += (x * BIOSCD_SECSIZE);
358 /* hexdump(dest, (blks * BIOSCD_SECSIZE)); */
363 * Return a suitable dev_t value for (dev).
366 bc_getdev(struct i386_devdesc *dev)
373 biosdev = bc_unit2bios(unit);
374 DEBUG("unit %d BIOS device %d", unit, biosdev);
375 if (biosdev == -1) /* not a BIOS device */
379 * XXX: Need to examine device spec here to figure out if SCSI or
380 * ATAPI. No idea on how to figure out device number. All we can
381 * really pass to the kernel is what bus and device on which bus we
382 * were booted from, which dev_t isn't well suited to since those
383 * number don't match to unit numbers very well. We may just need
384 * to engage in a hack where we pass -C to the boot args if we are
390 /* XXX: Assume partition 'a'. */
391 rootdev = MAKEBOOTDEV(major, 0, unit, 0);
392 DEBUG("dev is 0x%x\n", rootdev);