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
27 * $FreeBSD: src/sys/boot/i386/libi386/bioscd.c,v 1.5 2003/08/25 23:28:31 obrien Exp $
28 * $DragonFly: src/sys/boot/pc32/libi386/bioscd.c,v 1.6 2006/09/10 01:26:31 dillon Exp $
31 * BIOS CD device handling for CD's that have been booted off of via no
32 * emulation booting as defined in the El Torito standard.
34 * Ideas and algorithms from:
36 * - FreeBSD libi386/biosdisk.c
42 #include <sys/param.h>
43 #include <machine/bootinfo.h>
44 #include <machine/psl.h>
48 #include <bootstrap.h>
52 #define BIOSCD_SECSIZE 2048
53 #define BUFSIZE (1 * BIOSCD_SECSIZE)
56 /* Major numbers for devices we frontend for. */
61 # define DEBUG(fmt, args...) printf("%s: " fmt "\n" , __func__ , ## args)
63 # define DEBUG(fmt, args...)
66 struct specification_packet {
72 u_short sp_devicespec;
73 u_short sp_buffersegment;
74 u_short sp_loadsegment;
75 u_short sp_sectorcount;
81 * List of BIOS devices, translation from disk unit number to
84 static struct bcinfo {
85 int bc_unit; /* BIOS unit number */
86 struct specification_packet bc_sp;
88 static int nbcinfo = 0;
90 static int bc_read(int unit, daddr_t dblk, int blks, caddr_t dest);
91 static int bc_init(void);
92 static int bc_strategy(void *devdata, int flag, daddr_t dblk,
93 size_t size, char *buf, size_t *rsize);
94 static int bc_open(struct open_file *f, ...);
95 static int bc_close(struct open_file *f);
96 static void bc_print(int verbose);
98 struct devsw bioscd = {
111 * Translate between BIOS device numbers and our private unit numbers.
114 bc_bios2unit(int biosdev)
118 DEBUG("looking for bios device 0x%x", biosdev);
119 for (i = 0; i < nbcinfo; i++) {
120 DEBUG("bc unit %d is BIOS device 0x%x", i, bcinfo[i].bc_unit);
121 if (bcinfo[i].bc_unit == biosdev)
128 bc_unit2bios(int unit)
130 if ((unit >= 0) && (unit < nbcinfo))
131 return(bcinfo[unit].bc_unit);
136 * We can't quiz, we have to be told what device to use, so this functoin
137 * doesn't do anything. Instead, the loader calls bc_add() with the BIOS
138 * device number to add.
151 if (nbcinfo >= MAXBCDEV)
153 bcinfo[nbcinfo].bc_unit = biosdev;
158 v86.ds = VTOPSEG(&bcinfo[nbcinfo].bc_sp);
159 v86.esi = VTOPOFF(&bcinfo[nbcinfo].bc_sp);
161 if ((v86.eax & 0xff00) != 0)
164 printf("BIOS CD is cd%d\n", nbcinfo);
170 * Print information about disks
173 bc_print(int verbose)
178 for (i = 0; i < nbcinfo; i++) {
179 sprintf(line, " cd%d: Device 0x%x\n", i,
180 bcinfo[i].bc_sp.sp_devicespec);
186 * Attempt to open the disk described by (dev) for use by (f).
189 bc_open(struct open_file *f, ...)
192 struct i386_devdesc *dev;
196 dev = va_arg(ap, struct i386_devdesc *);
198 if (dev->d_kind.bioscd.unit >= nbcinfo) {
199 DEBUG("attempt to open nonexistent disk");
207 bc_close(struct open_file *f)
214 bc_strategy(void *devdata, int rw, daddr_t dblk, size_t size, char *buf,
217 struct i386_devdesc *dev;
220 #ifdef BD_SUPPORT_FRAGS
221 char fragbuf[BIOSCD_SECSIZE];
224 fragsize = size % BIOSCD_SECSIZE;
226 if (size % BIOSCD_SECSIZE)
232 dev = (struct i386_devdesc *)devdata;
233 unit = dev->d_kind.bioscd.unit;
234 blks = size / BIOSCD_SECSIZE;
235 if (dblk % (BIOSCD_SECSIZE / DEV_BSIZE) != 0)
237 dblk /= (BIOSCD_SECSIZE / DEV_BSIZE);
238 DEBUG("read %d from %d to %p", blks, dblk, buf);
242 if (blks && bc_read(unit, dblk, blks, buf)) {
246 #ifdef BD_SUPPORT_FRAGS
247 DEBUG("bc_strategy: frag read %d from %d+%d to %p",
248 fragsize, dblk, blks, buf + (blks * BIOSCD_SECSIZE));
249 if (fragsize && bc_read(unit, dblk + blks, 1, fragsize)) {
250 DEBUG("frag read error");
253 bcopy(fragbuf, buf + (blks * BIOSCD_SECSIZE), fragsize);
261 bc_read(int unit, daddr_t dblk, int blks, caddr_t dest)
263 u_int result, resid, retry;
264 static unsigned short packet[8];
270 /* Just in case some idiot actually tries to read -1 blocks... */
274 /* If nothing to do, just return succcess. */
278 biosdev = bc_unit2bios(unit);
280 * Loop retrying the operation a couple of times. The BIOS
283 for (retry = 0; retry < 3; retry++) {
284 /* If retrying, reset the drive */
295 packet[2] = VTOPOFF(dest);
296 packet[3] = VTOPSEG(dest);
297 packet[4] = dblk & 0xffff;
298 packet[5] = dblk >> 16;
305 v86.ds = VTOPSEG(packet);
306 v86.esi = VTOPOFF(packet);
308 result = (v86.efl & PSL_C);
314 error = (v86.eax >> 8) & 0xff;
316 DEBUG("%d sectors from %ld to %p (0x%x) %s", blks, dblk, dest,
317 VTOP(dest), result ? "failed" : "ok");
318 DEBUG("unit %d status 0x%x", unit, error);
320 /* hexdump(dest, (blks * BIOSCD_SECSIZE)); */
325 * Return a suitable cdev_t value for (dev).
328 bc_getdev(struct i386_devdesc *dev)
334 unit = dev->d_kind.bioscd.unit;
335 biosdev = bc_unit2bios(unit);
336 DEBUG("unit %d BIOS device %d", unit, biosdev);
337 if (biosdev == -1) /* not a BIOS device */
341 * XXX: Need to examine device spec here to figure out if SCSI or
342 * ATAPI. No idea on how to figure out device number. All we can
343 * really pass to the kernel is what bus and device on which bus we
344 * were booted from, which cdev_t isn't well suited to since those
345 * number don't match to unit numbers very well. We may just need
346 * to engage in a hack where we pass -C to the boot args if we are
352 /* XXX: Assume partition 'a'. */
353 rootdev = MAKEBOOTDEV(major, 0, 0, unit, 0);
354 DEBUG("dev is 0x%x\n", rootdev);