blob: 598cef681486f92ea8d931f64536951bc4317164 [file] [log] [blame]
/*
* Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
* Copyright (c) 2012 Andrey V. Elsukov <ae@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
/*
* BIOS disk device handling.
*
* Ideas and algorithms from:
*
* - NetBSD libi386/biosdisk.c
* - FreeBSD biosboot/disk.c
*
*/
#include <sys/disk.h>
#include <sys/limits.h>
#include <stand.h>
#include <machine/bootinfo.h>
#include <stdarg.h>
#include <bootstrap.h>
#include <btxv86.h>
#include <edd.h>
#include "disk.h"
#include "libi386.h"
#define BIOS_NUMDRIVES 0x475
#define BIOSDISK_SECSIZE 512
#define BUFSIZE (1 * BIOSDISK_SECSIZE)
#define DT_ATAPI 0x10 /* disk type for ATAPI floppies */
#define WDMAJOR 0 /* major numbers for devices we frontend for */
#define WFDMAJOR 1
#define FDMAJOR 2
#define DAMAJOR 4
#ifdef DISK_DEBUG
#define DEBUG(fmt, args...) printf("%s: " fmt "\n", __func__, ## args)
#else
#define DEBUG(fmt, args...)
#endif
/*
* List of BIOS devices, translation from disk unit number to
* BIOS unit number.
*/
static struct bdinfo
{
int bd_unit; /* BIOS unit number */
int bd_cyl; /* BIOS geometry */
int bd_hds;
int bd_sec;
int bd_flags;
#define BD_MODEINT13 0x0000
#define BD_MODEEDD1 0x0001
#define BD_MODEEDD3 0x0002
#define BD_MODEMASK 0x0003
#define BD_FLOPPY 0x0004
int bd_type; /* BIOS 'drive type' (floppy only) */
uint16_t bd_sectorsize; /* Sector size */
uint64_t bd_sectors; /* Disk size */
int bd_open; /* reference counter */
void *bd_bcache; /* buffer cache data */
} bdinfo [MAXBDDEV];
static int nbdinfo = 0;
#define BD(dev) (bdinfo[(dev)->dd.d_unit])
static void bd_io_workaround(struct disk_devdesc *dev);
static int bd_io(struct disk_devdesc *, daddr_t, int, caddr_t, int);
static int bd_int13probe(struct bdinfo *bd);
static int bd_init(void);
static int bd_strategy(void *devdata, int flag, daddr_t dblk, size_t size,
char *buf, size_t *rsize);
static int bd_realstrategy(void *devdata, int flag, daddr_t dblk, size_t size,
char *buf, size_t *rsize);
static int bd_open(struct open_file *f, ...);
static int bd_close(struct open_file *f);
static int bd_ioctl(struct open_file *f, u_long cmd, void *data);
static int bd_print(int verbose);
struct devsw biosdisk = {
"disk",
DEVT_DISK,
bd_init,
bd_strategy,
bd_open,
bd_close,
bd_ioctl,
bd_print,
NULL
};
/*
* Translate between BIOS device numbers and our private unit numbers.
*/
int
bd_bios2unit(int biosdev)
{
int i;
DEBUG("looking for bios device 0x%x", biosdev);
for (i = 0; i < nbdinfo; i++) {
DEBUG("bd unit %d is BIOS device 0x%x", i, bdinfo[i].bd_unit);
if (bdinfo[i].bd_unit == biosdev)
return (i);
}
return (-1);
}
int
bd_unit2bios(int unit)
{
if ((unit >= 0) && (unit < nbdinfo))
return (bdinfo[unit].bd_unit);
return (-1);
}
/*
* Quiz the BIOS for disk devices, save a little info about them.
*/
static int
bd_init(void)
{
int base, unit, nfd = 0;
/* sequence 0, 0x80 */
for (base = 0; base <= 0x80; base += 0x80) {
for (unit = base; (nbdinfo < MAXBDDEV); unit++) {
#ifndef VIRTUALBOX
/*
* Check the BIOS equipment list for number
* of fixed disks.
*/
if (base == 0x80 &&
(nfd >= *(unsigned char *)PTOV(BIOS_NUMDRIVES)))
break;
#endif
bdinfo[nbdinfo].bd_open = 0;
bdinfo[nbdinfo].bd_bcache = NULL;
bdinfo[nbdinfo].bd_unit = unit;
bdinfo[nbdinfo].bd_flags = unit < 0x80 ? BD_FLOPPY: 0;
if (!bd_int13probe(&bdinfo[nbdinfo]))
break;
#ifndef BOOT2
/* XXX we need "disk aliases" to make this simpler */
printf("BIOS drive %c: is disk%d\n", (unit < 0x80) ?
('A' + unit): ('C' + unit - 0x80), nbdinfo);
#endif
nbdinfo++;
if (base == 0x80)
nfd++;
}
}
bcache_add_dev(nbdinfo);
return (0);
}
/*
* Try to detect a device supported by the legacy int13 BIOS
*/
static int
bd_int13probe(struct bdinfo *bd)
{
struct edd_params params;
int ret = 1; /* assume success */
v86.ctl = V86_FLAGS;
v86.addr = 0x13;
v86.eax = 0x800;
v86.edx = bd->bd_unit;
v86int();
/* Don't error out if we get bad sector number, try EDD as well */
if (V86_CY(v86.efl) || /* carry set */
(v86.edx & 0xff) <= (unsigned)(bd->bd_unit & 0x7f)) /* unit # bad */
return (0); /* skip device */
if ((v86.ecx & 0x3f) == 0) /* absurd sector number */
ret = 0; /* set error */
/* Convert max cyl # -> # of cylinders */
bd->bd_cyl = ((v86.ecx & 0xc0) << 2) + ((v86.ecx & 0xff00) >> 8) + 1;
/* Convert max head # -> # of heads */
bd->bd_hds = ((v86.edx & 0xff00) >> 8) + 1;
bd->bd_sec = v86.ecx & 0x3f;
bd->bd_type = v86.ebx & 0xff;
bd->bd_flags |= BD_MODEINT13;
/* Calculate sectors count from the geometry */
bd->bd_sectors = bd->bd_cyl * bd->bd_hds * bd->bd_sec;
bd->bd_sectorsize = BIOSDISK_SECSIZE;
DEBUG("unit 0x%x geometry %d/%d/%d", bd->bd_unit, bd->bd_cyl,
bd->bd_hds, bd->bd_sec);
/* Determine if we can use EDD with this device. */
v86.ctl = V86_FLAGS;
v86.addr = 0x13;
v86.eax = 0x4100;
v86.edx = bd->bd_unit;
v86.ebx = 0x55aa;
v86int();
if (V86_CY(v86.efl) || /* carry set */
(v86.ebx & 0xffff) != 0xaa55 || /* signature */
(v86.ecx & EDD_INTERFACE_FIXED_DISK) == 0)
return (ret); /* return code from int13 AH=08 */
/* EDD supported */
bd->bd_flags |= BD_MODEEDD1;
if ((v86.eax & 0xff00) >= 0x3000)
bd->bd_flags |= BD_MODEEDD3;
/* Get disk params */
params.len = sizeof (struct edd_params);
v86.ctl = V86_FLAGS;
v86.addr = 0x13;
v86.eax = 0x4800;
v86.edx = bd->bd_unit;
v86.ds = VTOPSEG(&params);
v86.esi = VTOPOFF(&params);
v86int();
if (!V86_CY(v86.efl)) {
uint64_t total;
/*
* Sector size must be a multiple of 512 bytes.
* An alternate test would be to check power of 2,
* powerof2(params.sector_size).
*/
if (params.sector_size % BIOSDISK_SECSIZE)
bd->bd_sectorsize = BIOSDISK_SECSIZE;
else
bd->bd_sectorsize = params.sector_size;
total = bd->bd_sectorsize * params.sectors;
if (params.sectors != 0) {
/* Only update if we did not overflow. */
if (total > params.sectors)
bd->bd_sectors = params.sectors;
}
total = (uint64_t)params.cylinders *
params.heads * params.sectors_per_track;
if (total > 0 && bd->bd_sectors > total)
bd->bd_sectors = total;
ret = 1;
}
DEBUG("unit 0x%x flags %x, sectors %llu, sectorsize %u",
bd->bd_unit, bd->bd_flags, bd->bd_sectors, bd->bd_sectorsize);
return (ret);
}
/*
* Print information about disks
*/
static int
bd_print(int verbose)
{
static char line[80];
struct disk_devdesc dev;
int i, ret = 0;
if (nbdinfo == 0)
return (0);
printf("%s devices:", biosdisk.dv_name);
if ((ret = pager_output("\n")) != 0)
return (ret);
for (i = 0; i < nbdinfo; i++) {
snprintf(line, sizeof (line),
" disk%d: BIOS drive %c (%ju X %u):\n", i,
(bdinfo[i].bd_unit < 0x80) ? ('A' + bdinfo[i].bd_unit):
('C' + bdinfo[i].bd_unit - 0x80),
(uintmax_t)bdinfo[i].bd_sectors,
bdinfo[i].bd_sectorsize);
if ((ret = pager_output(line)) != 0)
break;
dev.dd.d_dev = &biosdisk;
dev.dd.d_unit = i;
dev.d_slice = -1;
dev.d_partition = -1;
if (disk_open(&dev,
bdinfo[i].bd_sectorsize * bdinfo[i].bd_sectors,
bdinfo[i].bd_sectorsize) == 0) {
snprintf(line, sizeof (line), " disk%d", i);
ret = disk_print(&dev, line, verbose);
disk_close(&dev);
if (ret != 0)
break;
}
}
return (ret);
}
/*
* Attempt to open the disk described by (dev) for use by (f).
*
* Note that the philosophy here is "give them exactly what
* they ask for". This is necessary because being too "smart"
* about what the user might want leads to complications.
* (eg. given no slice or partition value, with a disk that is
* sliced - are they after the first BSD slice, or the DOS
* slice before it?)
*/
static int
bd_open(struct open_file *f, ...)
{
struct disk_devdesc *dev;
struct disk_devdesc disk;
va_list ap;
uint64_t size;
int rc;
va_start(ap, f);
dev = va_arg(ap, struct disk_devdesc *);
va_end(ap);
if (dev->dd.d_unit < 0 || dev->dd.d_unit >= nbdinfo)
return (EIO);
BD(dev).bd_open++;
if (BD(dev).bd_bcache == NULL)
BD(dev).bd_bcache = bcache_allocate();
/*
* Read disk size from partition.
* This is needed to work around buggy BIOS systems returning
* wrong (truncated) disk media size.
* During bd_probe() we tested if the mulitplication of bd_sectors
* would overflow so it should be safe to perform here.
*/
disk.dd.d_dev = dev->dd.d_dev;
disk.dd.d_unit = dev->dd.d_unit;
disk.d_slice = -1;
disk.d_partition = -1;
disk.d_offset = 0;
if (disk_open(&disk, BD(dev).bd_sectors * BD(dev).bd_sectorsize,
BD(dev).bd_sectorsize) == 0) {
if (disk_ioctl(&disk, DIOCGMEDIASIZE, &size) == 0) {
size /= BD(dev).bd_sectorsize;
if (size > BD(dev).bd_sectors)
BD(dev).bd_sectors = size;
}
disk_close(&disk);
}
rc = disk_open(dev, BD(dev).bd_sectors * BD(dev).bd_sectorsize,
BD(dev).bd_sectorsize);
if (rc != 0) {
BD(dev).bd_open--;
if (BD(dev).bd_open == 0) {
bcache_free(BD(dev).bd_bcache);
BD(dev).bd_bcache = NULL;
}
}
return (rc);
}
static int
bd_close(struct open_file *f)
{
struct disk_devdesc *dev;
dev = (struct disk_devdesc *)f->f_devdata;
BD(dev).bd_open--;
if (BD(dev).bd_open == 0) {
bcache_free(BD(dev).bd_bcache);
BD(dev).bd_bcache = NULL;
}
return (disk_close(dev));
}
static int
bd_ioctl(struct open_file *f, u_long cmd, void *data)
{
struct disk_devdesc *dev;
int rc;
dev = (struct disk_devdesc *)f->f_devdata;
rc = disk_ioctl(dev, cmd, data);
if (rc != ENOTTY)
return (rc);
switch (cmd) {
case DIOCGSECTORSIZE:
*(uint32_t *)data = BD(dev).bd_sectorsize;
break;
case DIOCGMEDIASIZE:
*(uint64_t *)data = BD(dev).bd_sectors * BD(dev).bd_sectorsize;
break;
default:
return (ENOTTY);
}
return (0);
}
static int
bd_strategy(void *devdata, int rw, daddr_t dblk, size_t size,
char *buf, size_t *rsize)
{
struct bcache_devdata bcd;
struct disk_devdesc *dev;
dev = (struct disk_devdesc *)devdata;
bcd.dv_strategy = bd_realstrategy;
bcd.dv_devdata = devdata;
bcd.dv_cache = BD(dev).bd_bcache;
return (bcache_strategy(&bcd, rw, dblk + dev->d_offset, size,
buf, rsize));
}
static int
bd_realstrategy(void *devdata, int rw, daddr_t dblk, size_t size,
char *buf, size_t *rsize)
{
struct disk_devdesc *dev = (struct disk_devdesc *)devdata;
uint64_t disk_blocks, offset;
size_t blks, blkoff, bsize, rest;
caddr_t bbuf;
int rc;
/*
* First make sure the IO size is a multiple of 512 bytes. While we do
* process partial reads below, the strategy mechanism is built
* assuming IO is a multiple of 512B blocks. If the request is not
* a multiple of 512B blocks, it has to be some sort of bug.
*/
if (size == 0 || (size % BIOSDISK_SECSIZE) != 0) {
printf("bd_strategy: %d bytes I/O not multiple of %d\n",
size, BIOSDISK_SECSIZE);
return (EIO);
}
DEBUG("open_disk %p", dev);
offset = dblk * BIOSDISK_SECSIZE;
dblk = offset / BD(dev).bd_sectorsize;
blkoff = offset % BD(dev).bd_sectorsize;
/*
* Check the value of the size argument. We do have quite small
* heap (64MB), but we do not know good upper limit, so we check against
* INT_MAX here. This will also protect us against possible overflows
* while translating block count to bytes.
*/
if (size > INT_MAX) {
DEBUG("too large I/O: %zu bytes", size);
return (EIO);
}
blks = size / BD(dev).bd_sectorsize;
if (blks == 0 || (size % BD(dev).bd_sectorsize) != 0)
blks++;
if (dblk > dblk + blks)
return (EIO);
if (rsize)
*rsize = 0;
/*
* Get disk blocks, this value is either for whole disk or for
* partition.
*/
if (disk_ioctl(dev, DIOCGMEDIASIZE, &disk_blocks) == 0) {
/* DIOCGMEDIASIZE does return bytes. */
disk_blocks /= BD(dev).bd_sectorsize;
} else {
/* We should not get here. Just try to survive. */
disk_blocks = BD(dev).bd_sectors - dev->d_offset;
}
/* Validate source block address. */
if (dblk < dev->d_offset || dblk >= dev->d_offset + disk_blocks)
return (EIO);
/*
* Truncate if we are crossing disk or partition end.
*/
if (dblk + blks >= dev->d_offset + disk_blocks) {
blks = dev->d_offset + disk_blocks - dblk;
size = blks * BD(dev).bd_sectorsize;
DEBUG("short I/O %d", blks);
}
if (V86_IO_BUFFER_SIZE / BD(dev).bd_sectorsize == 0)
panic("BUG: Real mode buffer is too small\n");
bbuf = PTOV(V86_IO_BUFFER);
rest = size;
while (blks > 0) {
int x = min(blks, V86_IO_BUFFER_SIZE / BD(dev).bd_sectorsize);
switch (rw & F_MASK) {
case F_READ:
DEBUG("read %d from %lld to %p", x, dblk, buf);
bsize = BD(dev).bd_sectorsize * x - blkoff;
if (rest < bsize)
bsize = rest;
if ((rc = bd_io(dev, dblk, x, bbuf, 0)) != 0)
return (EIO);
bcopy(bbuf + blkoff, buf, bsize);
break;
case F_WRITE :
DEBUG("write %d from %lld to %p", x, dblk, buf);
if (blkoff != 0) {
/*
* We got offset to sector, read 1 sector to
* bbuf.
*/
x = 1;
bsize = BD(dev).bd_sectorsize - blkoff;
bsize = min(bsize, rest);
rc = bd_io(dev, dblk, x, bbuf, 0);
} else if (rest < BD(dev).bd_sectorsize) {
/*
* The remaining block is not full
* sector. Read 1 sector to bbuf.
*/
x = 1;
bsize = rest;
rc = bd_io(dev, dblk, x, bbuf, 0);
} else {
/* We can write full sector(s). */
bsize = BD(dev).bd_sectorsize * x;
}
/*
* Put your Data In, Put your Data out,
* Put your Data In, and shake it all about
*/
bcopy(buf, bbuf + blkoff, bsize);
if ((rc = bd_io(dev, dblk, x, bbuf, 1)) != 0)
return (EIO);
break;
default:
/* DO NOTHING */
return (EROFS);
}
blkoff = 0;
buf += bsize;
rest -= bsize;
blks -= x;
dblk += x;
}
if (rsize != NULL)
*rsize = size;
return (0);
}
static int
bd_edd_io(struct disk_devdesc *dev, daddr_t dblk, int blks, caddr_t dest,
int dowrite)
{
static struct edd_packet packet;
packet.len = sizeof (struct edd_packet);
packet.count = blks;
packet.off = VTOPOFF(dest);
packet.seg = VTOPSEG(dest);
packet.lba = dblk;
v86.ctl = V86_FLAGS;
v86.addr = 0x13;
/* Should we Write with verify ?? 0x4302 ? */
if (dowrite)
v86.eax = 0x4300;
else
v86.eax = 0x4200;
v86.edx = BD(dev).bd_unit;
v86.ds = VTOPSEG(&packet);
v86.esi = VTOPOFF(&packet);
v86int();
if (V86_CY(v86.efl))
return (v86.eax >> 8);
return (0);
}
static int
bd_chs_io(struct disk_devdesc *dev, daddr_t dblk, int blks, caddr_t dest,
int dowrite)
{
uint32_t x, bpc, cyl, hd, sec;
bpc = BD(dev).bd_sec * BD(dev).bd_hds; /* blocks per cylinder */
x = dblk;
cyl = x / bpc; /* block # / blocks per cylinder */
x %= bpc; /* block offset into cylinder */
hd = x / BD(dev).bd_sec; /* offset / blocks per track */
sec = x % BD(dev).bd_sec; /* offset into track */
/* correct sector number for 1-based BIOS numbering */
sec++;
if (cyl > 1023) {
/* CHS doesn't support cylinders > 1023. */
return (1);
}
v86.ctl = V86_FLAGS;
v86.addr = 0x13;
if (dowrite)
v86.eax = 0x300 | blks;
else
v86.eax = 0x200 | blks;
v86.ecx = ((cyl & 0xff) << 8) | ((cyl & 0x300) >> 2) | sec;
v86.edx = (hd << 8) | BD(dev).bd_unit;
v86.es = VTOPSEG(dest);
v86.ebx = VTOPOFF(dest);
v86int();
if (V86_CY(v86.efl))
return (v86.eax >> 8);
return (0);
}
static void
bd_io_workaround(struct disk_devdesc *dev)
{
uint8_t buf[8 * 1024];
bd_edd_io(dev, 0xffffffff, 1, (caddr_t)buf, 0);
}
static int
bd_io(struct disk_devdesc *dev, daddr_t dblk, int blks, caddr_t dest,
int dowrite)
{
int result, retry;
/* Just in case some idiot actually tries to read/write -1 blocks... */
if (blks < 0)
return (-1);
/*
* Workaround for a problem with some HP ProLiant BIOS failing to work
* out the boot disk after installation. hrs and kuriyama discovered
* this problem with an HP ProLiant DL320e Gen 8 with a 3TB HDD, and
* discovered that an int13h call seems to cause a buffer overrun in
* the bios. The problem is alleviated by doing an extra read before
* the buggy read. It is not immediately known whether other models
* are similarly affected.
* Loop retrying the operation a couple of times. The BIOS
* may also retry.
*/
if (dowrite == 0 && dblk >= 0x100000000)
bd_io_workaround(dev);
for (retry = 0; retry < 3; retry++) {
/* if retrying, reset the drive */
if (retry > 0) {
v86.ctl = V86_FLAGS;
v86.addr = 0x13;
v86.eax = 0;
v86.edx = BD(dev).bd_unit;
v86int();
}
if (BD(dev).bd_flags & BD_MODEEDD1)
result = bd_edd_io(dev, dblk, blks, dest, dowrite);
else
result = bd_chs_io(dev, dblk, blks, dest, dowrite);
if (result == 0)
break;
}
/*
* 0x20 - Controller failure. This is common error when the
* media is not present.
*/
if (result != 0 && result != 0x20) {
if (dowrite != 0) {
printf("%s%d: Write %d sector(s) from %p (0x%x) "
"to %lld: 0x%x\n", dev->dd.d_dev->dv_name,
dev->dd.d_unit, blks, dest, VTOP(dest), dblk,
result);
} else {
printf("%s%d: Read %d sector(s) from %lld to %p "
"(0x%x): 0x%x\n", dev->dd.d_dev->dv_name,
dev->dd.d_unit, blks, dblk, dest, VTOP(dest),
result);
}
}
return (result);
}
/*
* Return the BIOS geometry of a given "fixed drive" in a format
* suitable for the legacy bootinfo structure. Since the kernel is
* expecting raw int 0x13/0x8 values for N_BIOS_GEOM drives, we
* prefer to get the information directly, rather than rely on being
* able to put it together from information already maintained for
* different purposes and for a probably different number of drives.
*
* For valid drives, the geometry is expected in the format (31..0)
* "000000cc cccccccc hhhhhhhh 00ssssss"; and invalid drives are
* indicated by returning the geometry of a "1.2M" PC-format floppy
* disk. And, incidentally, what is returned is not the geometry as
* such but the highest valid cylinder, head, and sector numbers.
*/
uint32_t
bd_getbigeom(int bunit)
{
v86.ctl = V86_FLAGS;
v86.addr = 0x13;
v86.eax = 0x800;
v86.edx = 0x80 + bunit;
v86int();
if (V86_CY(v86.efl))
return (0x4f010f);
return (((v86.ecx & 0xc0) << 18) | ((v86.ecx & 0xff00) << 8) |
(v86.edx & 0xff00) | (v86.ecx & 0x3f));
}
/*
* Return a suitable dev_t value for (dev).
*
* In the case where it looks like (dev) is a SCSI disk, we allow the number of
* IDE disks to be specified in $num_ide_disks. There should be a Better Way.
*/
int
bd_getdev(struct i386_devdesc *d)
{
struct disk_devdesc *dev;
int biosdev;
int major;
int rootdev;
char *nip, *cp;
int i, unit;
dev = (struct disk_devdesc *)d;
biosdev = bd_unit2bios(dev->dd.d_unit);
DEBUG("unit %d BIOS device %d", dev->dd.d_unit, biosdev);
if (biosdev == -1) /* not a BIOS device */
return (-1);
if (disk_open(dev, BD(dev).bd_sectors * BD(dev).bd_sectorsize,
BD(dev).bd_sectorsize) != 0) /* oops, not a viable device */
return (-1);
else
disk_close(dev);
if (biosdev < 0x80) {
/* floppy (or emulated floppy) or ATAPI device */
if (bdinfo[dev->dd.d_unit].bd_type == DT_ATAPI) {
/* is an ATAPI disk */
major = WFDMAJOR;
} else {
/* is a floppy disk */
major = FDMAJOR;
}
} else {
/* assume an IDE disk */
major = WDMAJOR;
}
/* default root disk unit number */
unit = biosdev & 0x7f;
/* XXX a better kludge to set the root disk unit number */
if ((nip = getenv("root_disk_unit")) != NULL) {
i = strtol(nip, &cp, 0);
/* check for parse error */
if ((cp != nip) && (*cp == 0))
unit = i;
}
rootdev = MAKEBOOTDEV(major, dev->d_slice + 1, unit, dev->d_partition);
DEBUG("dev is 0x%x\n", rootdev);
return (rootdev);
}