bioscd.c revision 158559
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 28#include <sys/cdefs.h> 29__FBSDID("$FreeBSD: head/sys/boot/pc98/libpc98/bioscd.c 158559 2006-05-14 07:26:02Z nyan $"); 30 31/* 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. 34 * 35 * Ideas and algorithms from: 36 * 37 * - FreeBSD libi386/biosdisk.c 38 * 39 */ 40 41#include <stand.h> 42 43#include <sys/param.h> 44#include <machine/bootinfo.h> 45#include <machine/psl.h> 46 47#include <stdarg.h> 48 49#include <bootstrap.h> 50#include <btxv86.h> 51#include "libi386.h" 52 53#define BIOSCD_SECSIZE 2048 54#define BUFSIZE (1 * BIOSCD_SECSIZE) 55#define MAXBCDEV 1 56 57/* Major numbers for devices we frontend for. */ 58#define ACDMAJOR 117 59#define CDMAJOR 15 60 61#ifdef DISK_DEBUG 62# define DEBUG(fmt, args...) printf("%s: " fmt "\n" , __func__ , ## args) 63#else 64# define DEBUG(fmt, args...) 65#endif 66 67struct specification_packet { 68 u_char sp_size; 69 u_char sp_bootmedia; 70 u_char sp_drive; 71 u_char sp_controller; 72 u_int sp_lba; 73 u_short sp_devicespec; 74 u_short sp_buffersegment; 75 u_short sp_loadsegment; 76 u_short sp_sectorcount; 77 u_short sp_cylsec; 78 u_char sp_head; 79}; 80 81/* 82 * List of BIOS devices, translation from disk unit number to 83 * BIOS unit number. 84 */ 85static struct bcinfo { 86 int bc_unit; /* BIOS unit number */ 87 struct specification_packet bc_sp; 88} bcinfo [MAXBCDEV]; 89static int nbcinfo = 0; 90 91static int bc_read(int unit, daddr_t dblk, int blks, caddr_t dest); 92static int bc_init(void); 93static int bc_strategy(void *devdata, int flag, daddr_t dblk, 94 size_t size, char *buf, size_t *rsize); 95static int bc_open(struct open_file *f, ...); 96static int bc_close(struct open_file *f); 97static void bc_print(int verbose); 98 99struct devsw bioscd = { 100 "cd", 101 DEVT_CD, 102 bc_init, 103 bc_strategy, 104 bc_open, 105 bc_close, 106 noioctl, 107 bc_print, 108 NULL 109}; 110 111/* 112 * Translate between BIOS device numbers and our private unit numbers. 113 */ 114int 115bc_bios2unit(int biosdev) 116{ 117 int i; 118 119 DEBUG("looking for bios device 0x%x", biosdev); 120 for (i = 0; i < nbcinfo; i++) { 121 DEBUG("bc unit %d is BIOS device 0x%x", i, bcinfo[i].bc_unit); 122 if (bcinfo[i].bc_unit == biosdev) 123 return(i); 124 } 125 return(-1); 126} 127 128int 129bc_unit2bios(int unit) 130{ 131 if ((unit >= 0) && (unit < nbcinfo)) 132 return(bcinfo[unit].bc_unit); 133 return(-1); 134} 135 136/* 137 * We can't quiz, we have to be told what device to use, so this functoin 138 * doesn't do anything. Instead, the loader calls bc_add() with the BIOS 139 * device number to add. 140 */ 141static int 142bc_init(void) 143{ 144 145 return (0); 146} 147 148int 149bc_add(int biosdev) 150{ 151 152 if (nbcinfo >= MAXBCDEV) 153 return (-1); 154 bcinfo[nbcinfo].bc_unit = biosdev; 155 156 /* SCSI CD-ROM only */ 157 if ((biosdev & 0xf0) != 0xa0) 158 return (-1); 159 if ((((uint32_t *)PTOV(0xA1460))[biosdev & 0x0f] & 0x1f) != 5) 160 return (-1); 161 162 printf("BIOS CD is cd%d\n", nbcinfo); 163 nbcinfo++; 164 return(0); 165} 166 167/* 168 * Print information about disks 169 */ 170static void 171bc_print(int verbose) 172{ 173 int i; 174 char line[80]; 175 176 for (i = 0; i < nbcinfo; i++) { 177 sprintf(line, " cd%d: Device 0x%x\n", i, 178 bcinfo[i].bc_sp.sp_devicespec); 179 pager_output(line); 180 } 181} 182 183/* 184 * Attempt to open the disk described by (dev) for use by (f). 185 */ 186static int 187bc_open(struct open_file *f, ...) 188{ 189 va_list ap; 190 struct i386_devdesc *dev; 191 192 va_start(ap, f); 193 dev = va_arg(ap, struct i386_devdesc *); 194 va_end(ap); 195 if (dev->d_kind.bioscd.unit >= nbcinfo) { 196 DEBUG("attempt to open nonexistent disk"); 197 return(ENXIO); 198 } 199 200 return(0); 201} 202 203static int 204bc_close(struct open_file *f) 205{ 206 207 return(0); 208} 209 210static int 211bc_strategy(void *devdata, int rw, daddr_t dblk, size_t size, char *buf, 212 size_t *rsize) 213{ 214 struct i386_devdesc *dev; 215 int unit; 216 int blks; 217#ifdef BD_SUPPORT_FRAGS 218 char fragbuf[BIOSCD_SECSIZE]; 219 size_t fragsize; 220 221 fragsize = size % BIOSCD_SECSIZE; 222#else 223 if (size % BIOSCD_SECSIZE) 224 return (EINVAL); 225#endif 226 227 if (rw != F_READ) 228 return(EROFS); 229 dev = (struct i386_devdesc *)devdata; 230 unit = dev->d_kind.bioscd.unit; 231 blks = size / BIOSCD_SECSIZE; 232 if (dblk % (BIOSCD_SECSIZE / DEV_BSIZE) != 0) 233 return (EINVAL); 234 dblk /= (BIOSCD_SECSIZE / DEV_BSIZE); 235 DEBUG("read %d from %d to %p", blks, dblk, buf); 236 237 if (rsize) 238 *rsize = 0; 239 if (blks && bc_read(unit, dblk, blks, buf)) { 240 DEBUG("read error"); 241 return (EIO); 242 } 243#ifdef BD_SUPPORT_FRAGS 244 DEBUG("bc_strategy: frag read %d from %d+%d to %p", 245 fragsize, dblk, blks, buf + (blks * BIOSCD_SECSIZE)); 246 if (fragsize && bc_read(unit, dblk + blks, 1, fragsize)) { 247 DEBUG("frag read error"); 248 return(EIO); 249 } 250 bcopy(fragbuf, buf + (blks * BIOSCD_SECSIZE), fragsize); 251#endif 252 if (rsize) 253 *rsize = size; 254 return (0); 255} 256 257static int 258bc_read(int unit, daddr_t dblk, int blks, caddr_t dest) 259{ 260 u_int result, retry; 261 static unsigned short packet[8]; 262 int biosdev; 263#ifdef DISK_DEBUG 264 int error; 265#endif 266 267 /* Just in case some idiot actually tries to read -1 blocks... */ 268 if (blks < 0) 269 return (-1); 270 271 /* If nothing to do, just return succcess. */ 272 if (blks == 0) 273 return (0); 274 275 biosdev = bc_unit2bios(unit); 276 /* 277 * Loop retrying the operation a couple of times. The BIOS 278 * may also retry. 279 */ 280 for (retry = 0; retry < 3; retry++) { 281 /* If retrying, reset the drive */ 282 if (retry > 0) { 283 v86.ctl = V86_FLAGS; 284 v86.addr = 0x1b; 285 v86.eax = 0x0300 | biosdev; 286 v86int(); 287 } 288 289 v86.ctl = V86_FLAGS; 290 v86.addr = 0x1b; 291 v86.eax = 0x0600 | (biosdev & 0x7f); 292 v86.ebx = blks * BIOSCD_SECSIZE; 293 v86.ecx = dblk & 0xffff; 294 v86.edx = (dblk >> 16) & 0xffff; 295 v86.ebp = VTOPOFF(dest); 296 v86.es = VTOPSEG(dest); 297 v86int(); 298 result = (v86.efl & PSL_C); 299 if (result == 0) 300 break; 301 } 302 303#ifdef DISK_DEBUG 304 error = (v86.eax >> 8) & 0xff; 305#endif 306 DEBUG("%d sectors from %ld to %p (0x%x) %s", blks, dblk, dest, 307 VTOP(dest), result ? "failed" : "ok"); 308 DEBUG("unit %d status 0x%x", unit, error); 309 310/* hexdump(dest, (blks * BIOSCD_SECSIZE)); */ 311 return(0); 312} 313 314/* 315 * Return a suitable dev_t value for (dev). 316 */ 317int 318bc_getdev(struct i386_devdesc *dev) 319{ 320 int biosdev, unit, device; 321 int major; 322 int rootdev; 323 324 unit = dev->d_kind.bioscd.unit; 325 biosdev = bc_unit2bios(unit); 326 DEBUG("unit %d BIOS device %d", unit, biosdev); 327 if (biosdev == -1) /* not a BIOS device */ 328 return(-1); 329 330 device = biosdev & 0xf0; 331 if (device == 0x80) 332 major = ACDMAJOR; 333 else if (device == 0xa0) 334 major = CDMAJOR; 335 else 336 return (-1); 337 338 unit = 0; /* XXX */ 339 340 /* XXX: Assume partition 'a'. */ 341 rootdev = MAKEBOOTDEV(major, 0, 0, unit, 0); 342 DEBUG("dev is 0x%x\n", rootdev); 343 return(rootdev); 344} 345