| 1 | /*- |
| 2 | * Copyright (c) 1998 Michael Smith <msmith@freebsd.org> |
| 3 | * Copyright (c) 2001 John H. Baldwin <jhb@FreeBSD.org> |
| 4 | * All rights reserved. |
| 5 | * |
| 6 | * Redistribution and use in source and binary forms, with or without |
| 7 | * modification, are permitted provided that the following conditions |
| 8 | * are met: |
| 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. |
| 14 | * |
| 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 |
| 25 | * SUCH DAMAGE. |
| 26 | * |
| 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 1.5 2004/09/09 03:47:08 joerg Exp $ |
| 29 | */ |
| 30 | /* |
| 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. |
| 33 | * |
| 34 | * Ideas and algorithms from: |
| 35 | * |
| 36 | * - FreeBSD libi386/biosdisk.c |
| 37 | * |
| 38 | */ |
| 39 | |
| 40 | #include <stand.h> |
| 41 | |
| 42 | #include <sys/param.h> |
| 43 | #include <machine/bootinfo.h> |
| 44 | #include <machine/psl.h> |
| 45 | |
| 46 | #include <stdarg.h> |
| 47 | |
| 48 | #include <bootstrap.h> |
| 49 | #include <btxv86.h> |
| 50 | #include "libi386.h" |
| 51 | |
| 52 | #define BIOSCD_SECSIZE 2048 |
| 53 | #define BUFSIZE (1 * BIOSCD_SECSIZE) |
| 54 | #define MAXBCDEV 1 |
| 55 | |
| 56 | /* Major numbers for devices we frontend for. */ |
| 57 | #define ACDMAJOR 117 |
| 58 | #define CDMAJOR 15 |
| 59 | |
| 60 | #ifdef DISK_DEBUG |
| 61 | # define DEBUG(fmt, args...) printf("%s: " fmt "\n" , __func__ , ## args) |
| 62 | #else |
| 63 | # define DEBUG(fmt, args...) |
| 64 | #endif |
| 65 | |
| 66 | struct specification_packet { |
| 67 | u_char sp_size; |
| 68 | u_char sp_bootmedia; |
| 69 | u_char sp_drive; |
| 70 | u_char sp_controller; |
| 71 | u_int sp_lba; |
| 72 | u_short sp_devicespec; |
| 73 | u_short sp_buffersegment; |
| 74 | u_short sp_loadsegment; |
| 75 | u_short sp_sectorcount; |
| 76 | u_short sp_cylsec; |
| 77 | u_char sp_head; |
| 78 | }; |
| 79 | |
| 80 | /* |
| 81 | * List of BIOS devices, translation from disk unit number to |
| 82 | * BIOS unit number. |
| 83 | */ |
| 84 | static struct bcinfo { |
| 85 | int bc_unit; /* BIOS unit number */ |
| 86 | struct specification_packet bc_sp; |
| 87 | } bcinfo [MAXBCDEV]; |
| 88 | static int nbcinfo = 0; |
| 89 | |
| 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); |
| 97 | |
| 98 | struct devsw bioscd = { |
| 99 | "cd", |
| 100 | DEVT_CD, |
| 101 | bc_init, |
| 102 | bc_strategy, |
| 103 | bc_open, |
| 104 | bc_close, |
| 105 | noioctl, |
| 106 | bc_print, |
| 107 | NULL |
| 108 | }; |
| 109 | |
| 110 | /* |
| 111 | * Translate between BIOS device numbers and our private unit numbers. |
| 112 | */ |
| 113 | int |
| 114 | bc_bios2unit(int biosdev) |
| 115 | { |
| 116 | int i; |
| 117 | |
| 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) |
| 122 | return(i); |
| 123 | } |
| 124 | return(-1); |
| 125 | } |
| 126 | |
| 127 | int |
| 128 | bc_unit2bios(int unit) |
| 129 | { |
| 130 | if ((unit >= 0) && (unit < nbcinfo)) |
| 131 | return(bcinfo[unit].bc_unit); |
| 132 | return(-1); |
| 133 | } |
| 134 | |
| 135 | /* |
| 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. |
| 139 | */ |
| 140 | static int |
| 141 | bc_init(void) |
| 142 | { |
| 143 | |
| 144 | return (0); |
| 145 | } |
| 146 | |
| 147 | int |
| 148 | bc_add(int biosdev) |
| 149 | { |
| 150 | |
| 151 | if (nbcinfo >= MAXBCDEV) |
| 152 | return (-1); |
| 153 | bcinfo[nbcinfo].bc_unit = biosdev; |
| 154 | v86.ctl = V86_FLAGS; |
| 155 | v86.addr = 0x13; |
| 156 | v86.eax = 0x4b01; |
| 157 | v86.edx = biosdev; |
| 158 | v86.ds = VTOPSEG(&bcinfo[nbcinfo].bc_sp); |
| 159 | v86.esi = VTOPOFF(&bcinfo[nbcinfo].bc_sp); |
| 160 | v86int(); |
| 161 | if ((v86.eax & 0xff00) != 0) |
| 162 | return (-1); |
| 163 | |
| 164 | printf("BIOS CD is cd%d\n", nbcinfo); |
| 165 | nbcinfo++; |
| 166 | return(0); |
| 167 | } |
| 168 | |
| 169 | /* |
| 170 | * Print information about disks |
| 171 | */ |
| 172 | static void |
| 173 | bc_print(int verbose) |
| 174 | { |
| 175 | int i; |
| 176 | char line[80]; |
| 177 | |
| 178 | for (i = 0; i < nbcinfo; i++) { |
| 179 | sprintf(line, " cd%d: Device 0x%x\n", i, |
| 180 | bcinfo[i].bc_sp.sp_devicespec); |
| 181 | pager_output(line); |
| 182 | } |
| 183 | } |
| 184 | |
| 185 | /* |
| 186 | * Attempt to open the disk described by (dev) for use by (f). |
| 187 | */ |
| 188 | static int |
| 189 | bc_open(struct open_file *f, ...) |
| 190 | { |
| 191 | va_list ap; |
| 192 | struct i386_devdesc *dev; |
| 193 | int error; |
| 194 | |
| 195 | va_start(ap, f); |
| 196 | dev = va_arg(ap, struct i386_devdesc *); |
| 197 | va_end(ap); |
| 198 | if (dev->d_kind.bioscd.unit >= nbcinfo) { |
| 199 | DEBUG("attempt to open nonexistent disk"); |
| 200 | return(ENXIO); |
| 201 | } |
| 202 | |
| 203 | return(0); |
| 204 | } |
| 205 | |
| 206 | static int |
| 207 | bc_close(struct open_file *f) |
| 208 | { |
| 209 | |
| 210 | return(0); |
| 211 | } |
| 212 | |
| 213 | static int |
| 214 | bc_strategy(void *devdata, int rw, daddr_t dblk, size_t size, char *buf, |
| 215 | size_t *rsize) |
| 216 | { |
| 217 | struct i386_devdesc *dev; |
| 218 | int unit; |
| 219 | int blks; |
| 220 | #ifdef BD_SUPPORT_FRAGS |
| 221 | char fragbuf[BIOSCD_SECSIZE]; |
| 222 | size_t fragsize; |
| 223 | |
| 224 | fragsize = size % BIOSCD_SECSIZE; |
| 225 | #else |
| 226 | if (size % BIOSCD_SECSIZE) |
| 227 | return (EINVAL); |
| 228 | #endif |
| 229 | |
| 230 | if (rw != F_READ) |
| 231 | return(EROFS); |
| 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) |
| 236 | return (EINVAL); |
| 237 | dblk /= (BIOSCD_SECSIZE / DEV_BSIZE); |
| 238 | DEBUG("read %d from %d to %p", blks, dblk, buf); |
| 239 | |
| 240 | if (rsize) |
| 241 | *rsize = 0; |
| 242 | if (blks && bc_read(unit, dblk, blks, buf)) { |
| 243 | DEBUG("read error"); |
| 244 | return (EIO); |
| 245 | } |
| 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"); |
| 251 | return(EIO); |
| 252 | } |
| 253 | bcopy(fragbuf, buf + (blks * BIOSCD_SECSIZE), fragsize); |
| 254 | #endif |
| 255 | if (rsize) |
| 256 | *rsize = size; |
| 257 | return (0); |
| 258 | } |
| 259 | |
| 260 | static int |
| 261 | bc_read(int unit, daddr_t dblk, int blks, caddr_t dest) |
| 262 | { |
| 263 | u_int result, resid, retry; |
| 264 | static unsigned short packet[8]; |
| 265 | int biosdev; |
| 266 | #ifdef DISK_DEBUG |
| 267 | int error; |
| 268 | #endif |
| 269 | |
| 270 | /* Just in case some idiot actually tries to read -1 blocks... */ |
| 271 | if (blks < 0) |
| 272 | return (-1); |
| 273 | |
| 274 | /* If nothing to do, just return succcess. */ |
| 275 | if (blks == 0) |
| 276 | return (0); |
| 277 | |
| 278 | biosdev = bc_unit2bios(unit); |
| 279 | /* |
| 280 | * Loop retrying the operation a couple of times. The BIOS |
| 281 | * may also retry. |
| 282 | */ |
| 283 | for (retry = 0; retry < 3; retry++) { |
| 284 | /* If retrying, reset the drive */ |
| 285 | if (retry > 0) { |
| 286 | v86.ctl = V86_FLAGS; |
| 287 | v86.addr = 0x13; |
| 288 | v86.eax = 0; |
| 289 | v86.edx = biosdev; |
| 290 | v86int(); |
| 291 | } |
| 292 | |
| 293 | packet[0] = 0x10; |
| 294 | packet[1] = blks; |
| 295 | packet[2] = VTOPOFF(dest); |
| 296 | packet[3] = VTOPSEG(dest); |
| 297 | packet[4] = dblk & 0xffff; |
| 298 | packet[5] = dblk >> 16; |
| 299 | packet[6] = 0; |
| 300 | packet[7] = 0; |
| 301 | v86.ctl = V86_FLAGS; |
| 302 | v86.addr = 0x13; |
| 303 | v86.eax = 0x4200; |
| 304 | v86.edx = biosdev; |
| 305 | v86.ds = VTOPSEG(packet); |
| 306 | v86.esi = VTOPOFF(packet); |
| 307 | v86int(); |
| 308 | result = (v86.efl & PSL_C); |
| 309 | if (result == 0) |
| 310 | break; |
| 311 | } |
| 312 | |
| 313 | #ifdef DISK_DEBUG |
| 314 | error = (v86.eax >> 8) & 0xff; |
| 315 | #endif |
| 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); |
| 319 | |
| 320 | /* hexdump(dest, (blks * BIOSCD_SECSIZE)); */ |
| 321 | return(0); |
| 322 | } |
| 323 | |
| 324 | /* |
| 325 | * Return a suitable dev_t value for (dev). |
| 326 | */ |
| 327 | int |
| 328 | bc_getdev(struct i386_devdesc *dev) |
| 329 | { |
| 330 | int biosdev, unit; |
| 331 | int major; |
| 332 | int rootdev; |
| 333 | |
| 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 */ |
| 338 | return(-1); |
| 339 | |
| 340 | /* |
| 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 dev_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 |
| 347 | * the boot device. |
| 348 | */ |
| 349 | major = ACDMAJOR; |
| 350 | unit = 0; /* XXX */ |
| 351 | |
| 352 | /* XXX: Assume partition 'a'. */ |
| 353 | rootdev = MAKEBOOTDEV(major, 0, 0, unit, 0); |
| 354 | DEBUG("dev is 0x%x\n", rootdev); |
| 355 | return(rootdev); |
| 356 | } |