freebsd-dev/sys/boot/i386/libi386/biosdisk.c
Andrey V. Elsukov 9add094157 Add the flags parameter to the disk_open() function and DISK_F_NOCACHE
flag, that disables the caching of partition tables metadata.
Use this flag for floppies in the libi386/biosdisk driver.
2012-10-21 12:14:58 +00:00

685 lines
18 KiB
C

/*-
* 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>
__FBSDID("$FreeBSD$");
/*
* BIOS disk device handling.
*
* Ideas and algorithms from:
*
* - NetBSD libi386/biosdisk.c
* - FreeBSD biosboot/disk.c
*
*/
#include <sys/disk.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"
CTASSERT(sizeof(struct i386_devdesc) >= sizeof(struct disk_devdesc));
#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 */
} bdinfo [MAXBDDEV];
static int nbdinfo = 0;
#define BD(dev) (bdinfo[(dev)->d_unit])
static int bd_read(struct disk_devdesc *dev, daddr_t dblk, int blks,
caddr_t dest);
static int bd_write(struct disk_devdesc *dev, daddr_t dblk, int blks,
caddr_t dest);
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 void bd_print(int verbose);
static void bd_cleanup(void);
struct devsw biosdisk = {
"disk",
DEVT_DISK,
bd_init,
bd_strategy,
bd_open,
bd_close,
bd_ioctl,
bd_print,
bd_cleanup
};
/*
* 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_unit = unit;
bdinfo[nbdinfo].bd_flags = unit < 0x80 ? BD_FLOPPY: 0;
if (!bd_int13probe(&bdinfo[nbdinfo]))
break;
/* 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);
nbdinfo++;
if (base == 0x80)
nfd++;
}
}
return(0);
}
static void
bd_cleanup(void)
{
disk_cleanup(&biosdisk);
}
/*
* Try to detect a device supported by the legacy int13 BIOS
*/
static int
bd_int13probe(struct bdinfo *bd)
{
struct edd_params params;
v86.ctl = V86_FLAGS;
v86.addr = 0x13;
v86.eax = 0x800;
v86.edx = bd->bd_unit;
v86int();
if (V86_CY(v86.efl) || /* carry set */
(v86.ecx & 0x3f) == 0 || /* absurd sector number */
(v86.edx & 0xff) <= (unsigned)(bd->bd_unit & 0x7f)) /* unit # bad */
return (0); /* skip device */
/* 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 (1);
/* 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)) {
bd->bd_sectors = params.sectors;
bd->bd_sectorsize = params.sector_size;
}
DEBUG("unit 0x%x flags %x, sectors %llu, sectorsize %u",
bd->bd_unit, bd->bd_flags, bd->bd_sectors, bd->bd_sectorsize);
return (1);
}
/*
* Print information about disks
*/
static void
bd_print(int verbose)
{
static char line[80];
struct disk_devdesc dev;
int i;
for (i = 0; i < nbdinfo; i++) {
sprintf(line, " disk%d: BIOS drive %c:\n", i,
(bdinfo[i].bd_unit < 0x80) ? ('A' + bdinfo[i].bd_unit):
('C' + bdinfo[i].bd_unit - 0x80));
pager_output(line);
dev.d_dev = &biosdisk;
dev.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,
(bdinfo[i].bd_flags & BD_FLOPPY) ?
DISK_F_NOCACHE: 0) == 0) {
sprintf(line, " disk%d", i);
disk_print(&dev, line, verbose);
disk_close(&dev);
}
}
}
/*
* 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;
va_list ap;
va_start(ap, f);
dev = va_arg(ap, struct disk_devdesc *);
va_end(ap);
if (dev->d_unit < 0 || dev->d_unit >= nbdinfo)
return (EIO);
return (disk_open(dev, BD(dev).bd_sectors * BD(dev).bd_sectorsize,
BD(dev).bd_sectorsize, (BD(dev).bd_flags & BD_FLOPPY) ?
DISK_F_NOCACHE: 0));
}
static int
bd_close(struct open_file *f)
{
struct disk_devdesc *dev;
dev = (struct disk_devdesc *)f->f_devdata;
return (disk_close(dev));
}
static int
bd_ioctl(struct open_file *f, u_long cmd, void *data)
{
struct disk_devdesc *dev;
dev = (struct disk_devdesc *)f->f_devdata;
switch (cmd) {
case DIOCGSECTORSIZE:
*(u_int *)data = BD(dev).bd_sectorsize;
break;
case DIOCGMEDIASIZE:
*(off_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;
return (bcache_strategy(&bcd, BD(dev).bd_unit, 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;
int blks;
#ifdef BD_SUPPORT_FRAGS /* XXX: sector size */
char fragbuf[BIOSDISK_SECSIZE];
size_t fragsize;
fragsize = size % BIOSDISK_SECSIZE;
#else
if (size % BD(dev).bd_sectorsize)
panic("bd_strategy: %d bytes I/O not multiple of block size", size);
#endif
DEBUG("open_disk %p", dev);
blks = size / BD(dev).bd_sectorsize;
if (rsize)
*rsize = 0;
switch(rw){
case F_READ:
DEBUG("read %d from %lld to %p", blks, dblk, buf);
if (blks && bd_read(dev, dblk, blks, buf)) {
DEBUG("read error");
return (EIO);
}
#ifdef BD_SUPPORT_FRAGS /* XXX: sector size */
DEBUG("bd_strategy: frag read %d from %d+%d to %p",
fragsize, dblk, blks, buf + (blks * BIOSDISK_SECSIZE));
if (fragsize && bd_read(od, dblk + blks, 1, fragsize)) {
DEBUG("frag read error");
return(EIO);
}
bcopy(fragbuf, buf + (blks * BIOSDISK_SECSIZE), fragsize);
#endif
break;
case F_WRITE :
DEBUG("write %d from %d to %p", blks, dblk, buf);
if (blks && bd_write(dev, dblk, blks, buf)) {
DEBUG("write error");
return (EIO);
}
#ifdef BD_SUPPORT_FRAGS
if(fragsize) {
DEBUG("Attempted to write a frag");
return (EIO);
}
#endif
break;
default:
/* DO NOTHING */
return (EROFS);
}
if (rsize)
*rsize = size;
return (0);
}
/* Max number of sectors to bounce-buffer if the request crosses a 64k boundary */
#define FLOPPY_BOUNCEBUF 18
static int
bd_edd_io(struct disk_devdesc *dev, daddr_t dblk, int blks, caddr_t dest,
int write)
{
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;
if (write)
/* Should we Write with verify ?? 0x4302 ? */
v86.eax = 0x4300;
else
v86.eax = 0x4200;
v86.edx = BD(dev).bd_unit;
v86.ds = VTOPSEG(&packet);
v86.esi = VTOPOFF(&packet);
v86int();
return (V86_CY(v86.efl));
}
static int
bd_chs_io(struct disk_devdesc *dev, daddr_t dblk, int blks, caddr_t dest,
int write)
{
u_int 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 (write)
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();
return (V86_CY(v86.efl));
}
static int
bd_io(struct disk_devdesc *dev, daddr_t dblk, int blks, caddr_t dest, int write)
{
u_int x, sec, result, resid, retry, maxfer;
caddr_t p, xp, bbuf, breg;
/* Just in case some idiot actually tries to read/write -1 blocks... */
if (blks < 0)
return (-1);
resid = blks;
p = dest;
/* Decide whether we have to bounce */
if (VTOP(dest) >> 20 != 0 || (BD(dev).bd_unit < 0x80 &&
(VTOP(dest) >> 16) != (VTOP(dest +
blks * BD(dev).bd_sectorsize) >> 16))) {
/*
* There is a 64k physical boundary somewhere in the
* destination buffer, or the destination buffer is above
* first 1MB of physical memory so we have to arrange a
* suitable bounce buffer. Allocate a buffer twice as large
* as we need to. Use the bottom half unless there is a break
* there, in which case we use the top half.
*/
x = min(FLOPPY_BOUNCEBUF, (unsigned)blks);
bbuf = alloca(x * 2 * BD(dev).bd_sectorsize);
if (((u_int32_t)VTOP(bbuf) & 0xffff0000) ==
((u_int32_t)VTOP(bbuf + x * BD(dev).bd_sectorsize) & 0xffff0000)) {
breg = bbuf;
} else {
breg = bbuf + x * BD(dev).bd_sectorsize;
}
maxfer = x; /* limit transfers to bounce region size */
} else {
breg = bbuf = NULL;
maxfer = 0;
}
while (resid > 0) {
/*
* Play it safe and don't cross track boundaries.
* (XXX this is probably unnecessary)
*/
sec = dblk % BD(dev).bd_sec; /* offset into track */
x = min(BD(dev).bd_sec - sec, resid);
if (maxfer > 0)
x = min(x, maxfer); /* fit bounce buffer */
/* where do we transfer to? */
xp = bbuf == NULL ? p : breg;
/*
* Put your Data In, Put your Data out,
* Put your Data In, and shake it all about
*/
if (write && bbuf != NULL)
bcopy(p, breg, x * BD(dev).bd_sectorsize);
/*
* Loop retrying the operation a couple of times. The BIOS
* may also retry.
*/
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, x, xp, write);
else
result = bd_chs_io(dev, dblk, x, xp, write);
if (result == 0)
break;
}
if (write)
DEBUG("Write %d sector(s) from %p (0x%x) to %lld %s", x,
p, VTOP(p), dblk, result ? "failed" : "ok");
else
DEBUG("Read %d sector(s) from %lld to %p (0x%x) %s", x,
dblk, p, VTOP(p), result ? "failed" : "ok");
if (result) {
return(-1);
}
if (!write && bbuf != NULL)
bcopy(breg, p, x * BD(dev).bd_sectorsize);
p += (x * BD(dev).bd_sectorsize);
dblk += x;
resid -= x;
}
/* hexdump(dest, (blks * BD(dev).bd_sectorsize)); */
return(0);
}
static int
bd_read(struct disk_devdesc *dev, daddr_t dblk, int blks, caddr_t dest)
{
return (bd_io(dev, dblk, blks, dest, 0));
}
static int
bd_write(struct disk_devdesc *dev, daddr_t dblk, int blks, caddr_t dest)
{
return (bd_io(dev, dblk, blks, dest, 1));
}
/*
* 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.
*/
u_int32_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->d_unit);
DEBUG("unit %d BIOS device %d", dev->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,(BD(dev).bd_flags & BD_FLOPPY) ?
DISK_F_NOCACHE: 0) != 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->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);
}