src/sys/arch/amd64/amd64/dkcsum.c

230 lines
6.6 KiB
C

/* $OpenBSD: dkcsum.c,v 1.21 2014/09/14 14:17:23 jsg Exp $ */
/*-
* Copyright (c) 1997 Niklas Hallqvist. 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 ``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 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.
*/
/*
* A checksumming pseudo device used to get unique labels of each disk
* that needs to be matched to BIOS disks.
*/
#include <sys/param.h>
#include <sys/buf.h>
#include <sys/conf.h>
#include <sys/device.h>
#include <sys/disklabel.h>
#include <sys/fcntl.h>
#include <sys/reboot.h>
#include <sys/stat.h>
#include <sys/systm.h>
#include <machine/biosvar.h>
#include <lib/libz/zlib.h>
dev_t dev_rawpart(struct device *); /* XXX */
extern u_int32_t bios_cksumlen;
extern bios_diskinfo_t *bios_diskinfo;
extern dev_t bootdev;
void
dkcsumattach(void)
{
struct device *dv;
struct buf *bp;
struct bdevsw *bdsw;
dev_t dev, pribootdev, altbootdev;
int error, picked;
u_int32_t csum;
bios_diskinfo_t *bdi, *hit;
/* do nothing if no diskinfo passed from /boot, or a bad length */
if (bios_diskinfo == NULL || bios_cksumlen * DEV_BSIZE > MAXBSIZE)
return;
/* Do nothing if bootdev is a CD drive. */
if (B_TYPE(bootdev) == 6)
return;
#ifdef DEBUG
printf("dkcsum: bootdev=%#x\n", bootdev);
for (bdi = bios_diskinfo; bdi->bios_number != -1; bdi++) {
if (bdi->bios_number & 0x80) {
printf("dkcsum: BIOS drive %#x bsd_dev=%#x "
"checksum=%#x\n", bdi->bios_number, bdi->bsd_dev,
bdi->checksum);
}
}
#endif
pribootdev = altbootdev = 0;
/*
* XXX What if DEV_BSIZE is changed to something else than the BIOS
* blocksize? Today, /boot doesn't cover that case so neither need
* I care here.
*/
bp = geteblk(bios_cksumlen * DEV_BSIZE); /* XXX error check? */
TAILQ_FOREACH(dv, &alldevs, dv_list) {
if (dv->dv_class != DV_DISK)
continue;
bp->b_dev = dev = dev_rawpart(dv);
if (dev == NODEV)
continue;
bdsw = &bdevsw[major(dev)];
/*
* This open operation guarantees a proper initialization
* of the device, for future strategy calls.
*/
error = (*bdsw->d_open)(dev, FREAD, S_IFCHR, curproc);
if (error) {
/* XXX What to do here? */
#ifdef DEBUG
printf("dkcsum: %s open failed (%d)\n",
dv->dv_xname, error);
#endif
continue;
}
/* Read blocks to cksum. XXX maybe a d_read should be used. */
bp->b_blkno = 0;
bp->b_bcount = bios_cksumlen * DEV_BSIZE;
bp->b_error = 0; /* B_ERROR and b_error may have stale data. */
CLR(bp->b_flags, B_READ | B_WRITE | B_DONE | B_ERROR);
SET(bp->b_flags, B_BUSY | B_READ | B_RAW);
(*bdsw->d_strategy)(bp);
if ((error = biowait(bp))) {
/* XXX What to do here? */
#ifdef DEBUG
printf("dkcsum: %s read failed (%d)\n",
dv->dv_xname, error);
#endif
error = (*bdsw->d_close)(dev, 0, S_IFCHR, curproc);
#ifdef DEBUG
if (error)
printf("dkcsum: %s close failed (%d)\n",
dv->dv_xname, error);
#endif
continue;
}
error = (*bdsw->d_close)(dev, FREAD, S_IFCHR, curproc);
if (error) {
/* XXX What to do here? */
#ifdef DEBUG
printf("dkcsum: %s closed failed (%d)\n",
dv->dv_xname, error);
#endif
continue;
}
csum = adler32(0, bp->b_data, bios_cksumlen * DEV_BSIZE);
#ifdef DEBUG
printf("dkcsum: %s checksum is %#x\n", dv->dv_xname, csum);
#endif
/* Find the BIOS device */
hit = 0;
for (bdi = bios_diskinfo; bdi->bios_number != -1; bdi++) {
/* Skip non-harddrives */
if (!(bdi->bios_number & 0x80))
continue;
if (bdi->checksum != csum)
continue;
picked = hit || (bdi->flags & BDI_PICKED);
if (!picked)
hit = bdi;
#ifdef DEBUG
printf("dkcsum: %s matches BIOS drive %#x%s\n",
dv->dv_xname, bdi->bios_number,
(picked ? " IGNORED" : ""));
#endif
}
/*
* If we have no hit, that's OK, we can see a lot more devices
* than the BIOS can, so this case is pretty normal.
*/
if (!hit) {
#ifdef DEBUG
printf("dkcsum: %s has no matching BIOS drive\n",
dv->dv_xname);
#endif
continue;
}
/*
* Fixup bootdev if units match. This means that all of
* hd*, sd*, wd*, will be interpreted the same. Not 100%
* backwards compatible, but sd* and wd* should be phased-
* out in the bootblocks.
*/
/* B_TYPE dependent hd unit counting bootblocks */
if ((B_ADAPTOR(bootdev) == B_ADAPTOR(hit->bsd_dev)) &&
(B_CONTROLLER(bootdev) == B_CONTROLLER(hit->bsd_dev)) &&
(B_TYPE(bootdev) == B_TYPE(hit->bsd_dev)) &&
(B_UNIT(bootdev) == B_UNIT(hit->bsd_dev))) {
int type, ctrl, adap, part, unit;
type = major(bp->b_dev);
adap = B_ADAPTOR(bootdev);
ctrl = B_CONTROLLER(bootdev);
unit = DISKUNIT(bp->b_dev);
part = B_PARTITION(bootdev);
pribootdev = MAKEBOOTDEV(type, ctrl, adap, unit, part);
#ifdef DEBUG
printf("dkcsum: %s is primary boot disk\n",
dv->dv_xname);
#endif
}
/* B_TYPE independent hd unit counting bootblocks */
if (B_UNIT(bootdev) == (hit->bios_number & 0x7F)) {
int type, ctrl, adap, part, unit;
type = major(bp->b_dev);
adap = B_ADAPTOR(bootdev);
ctrl = B_CONTROLLER(bootdev);
unit = DISKUNIT(bp->b_dev);
part = B_PARTITION(bootdev);
altbootdev = MAKEBOOTDEV(type, ctrl, adap, unit, part);
#ifdef DEBUG
printf("dkcsum: %s is alternate boot disk\n",
dv->dv_xname);
#endif
}
/* This will overwrite /boot's guess, just so you remember */
hit->bsd_dev = MAKEBOOTDEV(major(bp->b_dev), 0, 0,
DISKUNIT(bp->b_dev), RAW_PART);
hit->flags |= BDI_PICKED;
}
bootdev = pribootdev ? pribootdev : altbootdev ? altbootdev : bootdev;
bp->b_flags |= B_INVAL;
brelse(bp);
}