static int
read_sector(mbr_args_t *a, uint sector, int count)
{
int error;
error = disk_read_sectors(a->strat, a->lp, a->bp, sector, count);
if (error != 0)
a->error = error;
return error;
}
static struct disk_gpt_header *try_gpt_hdr(const struct disk_info *di, int sec)
{
const char *desc = sec ? "backup" : "primary";
uint64_t gpt_cur = sec ? di->lbacnt - 1 : 1;
struct disk_gpt_header *gpth;
char errbuf[64];
gpth = disk_read_sectors(di, gpt_cur, 1);
if (!gpth) {
sprintf(errbuf, "Unable to read %s GPT header.", desc);
try_gpt_we(errbuf, sec);
return NULL;
}
if(!valid_crc_hdr(gpth)) {
sprintf(errbuf, "Invalid checksum of %s GPT header.", desc);
try_gpt_we(errbuf, sec);
free(gpth);
return NULL;
}
return gpth;
}
static struct disk_gpt_part_entry *try_gpt_list(const struct disk_info *di, const struct disk_gpt_header *gpth, int alt)
{
int pri = gpth->lba_cur < gpth->lba_alt;
const char *desc = alt ? "alternative" : "main";
struct disk_gpt_part_entry *gptl;
char errbuf[64];
uint64_t gpt_lsiz; /* size of GPT partition list in bytes */
uint64_t gpt_lcnt; /* size of GPT partition in sectors */
uint64_t gpt_loff; /* offset to GPT partition list in sectors */
gpt_lsiz = (uint64_t)gpth->part_size * gpth->part_count;
gpt_lcnt = (gpt_lsiz + di->bps - 1) / di->bps;
if (!alt) {
/* prefer header value for partition table if not asking for alternative */
gpt_loff = gpth->lba_table;
} else {
/* try to read alternative, we have to calculate its position */
if (!pri)
gpt_loff = gpth->lba_alt + 1;
else
gpt_loff = gpth->lba_alt - gpt_lcnt;
}
gptl = disk_read_sectors(di, gpt_loff, gpt_lcnt);
if (!gptl) {
sprintf(errbuf, "Unable to read %s GPT partition list.", desc);
try_gpt_we(errbuf, alt);
return NULL;
}
if (!valid_crc(gpth->table_chksum, (const uint8_t *)gptl, gpt_lsiz)) {
sprintf(errbuf, "Invalid checksum of %s GPT partition list.", desc);
try_gpt_we(errbuf, alt);
free(gptl);
return NULL;
}
return gptl;
}
/**
* pi_begin() - check disk, validate, and get proper iterator
* @di: diskinfo struct pointer
*
* This function checks the disk for GPT or legacy partition table and allocates
* an appropriate iterator.
**/
struct part_iter *pi_begin(const struct disk_info *di, int stepall)
{
int setraw = 0;
struct part_iter *iter = NULL;
struct disk_dos_mbr *mbr = NULL;
struct disk_gpt_header *gpth = NULL;
struct disk_gpt_part_entry *gptl = NULL;
/* Read MBR */
if (!(mbr = disk_read_sectors(di, 0, 1))) {
error("Couldn't read first disk sector.\n");
goto bail;
}
setraw = -1;
/* Check for MBR magic*/
if (mbr->sig != disk_mbr_sig_magic) {
error("No MBR magic.\n");
goto bail;
}
/* Check for GPT protective MBR */
if (mbr->table[0].ostype == 0xEE) {
if (!(gpth = disk_read_sectors(di, 1, 1))) {
error("Couldn't read potential GPT header.\n");
goto bail;
}
}
if (gpth && gpth->rev.uint32 == 0x00010000 &&
!memcmp(gpth->sig, disk_gpt_sig_magic, sizeof(disk_gpt_sig_magic))) {
/* looks like GPT v1.0 */
uint64_t gpt_loff; /* offset to GPT partition list in sectors */
uint64_t gpt_lsiz; /* size of GPT partition list in bytes */
uint64_t gpt_lcnt; /* size of GPT partition in sectors */
#ifdef DEBUG
puts("Looks like a GPT v1.0 disk.");
disk_gpt_header_dump(gpth);
#endif
/* Verify checksum, fallback to backup, then bail if invalid */
if (gpt_check_hdr_crc(di, &gpth))
goto bail;
gpt_loff = gpth->lba_table;
gpt_lsiz = (uint64_t)gpth->part_size * gpth->part_count;
gpt_lcnt = (gpt_lsiz + di->bps - 1) / di->bps;
/*
* disk_read_sectors allows reading of max 255 sectors, so we use
* it as a sanity check base. EFI doesn't specify max (AFAIK).
* Apart from that, some extensive sanity checks.
*/
if (!gpt_loff || !gpt_lsiz || gpt_lcnt > 255u ||
gpth->lba_first_usable > gpth->lba_last_usable ||
!sane(gpt_loff, gpt_lcnt) ||
gpt_loff + gpt_lcnt > gpth->lba_first_usable ||
!sane(gpth->lba_last_usable, gpt_lcnt) ||
gpth->lba_last_usable + gpt_lcnt >= gpth->lba_alt ||
gpth->lba_alt >= di->lbacnt ||
gpth->part_size < sizeof(struct disk_gpt_part_entry)) {
error("Invalid GPT header's values.\n");
goto bail;
}
if (!(gptl = disk_read_sectors(di, gpt_loff, (uint8_t)gpt_lcnt))) {
error("Couldn't read GPT partition list.\n");
goto bail;
}
/* Check array checksum(s). */
if (check_crc(gpth->table_chksum, (const uint8_t *)gptl, (unsigned int)gpt_lsiz)) {
error("WARNING: GPT partition list checksum invalid, trying backup.\n");
free(gptl);
/* secondary array directly precedes secondary header */
if (!(gptl = disk_read_sectors(di, gpth->lba_alt - gpt_lcnt, (uint8_t)gpt_lcnt))) {
error("Couldn't read backup GPT partition list.\n");
goto bail;
}
if (check_crc(gpth->table_chksum, (const uint8_t *)gptl, (unsigned int)gpt_lsiz)) {
error("Backup GPT partition list checksum invalid.\n");
goto bail;
}
}
/* allocate iterator and exit */
iter = pi_new(typegpt, di, stepall, gpth, gptl);
} else {
/* looks like MBR */
iter = pi_new(typedos, di, stepall, mbr);
}
setraw = 0;
bail:
if (setraw) {
error("WARNING: treating disk as raw.\n");
iter = pi_new(typeraw, di, stepall);
}
free(mbr);
free(gpth);
free(gptl);
return iter;
}
const char *
convertdisklabel(struct disklabel *lp, void (*strat)(struct buf *),
struct buf *bp, uint32_t secperunit)
{
struct partition rp, *altp, *p;
int geom_ok;
const char *str;
memset(&rp, 0, sizeof(rp));
rp.p_size = secperunit;
rp.p_fstype = FS_UNUSED;
/* If we can seek to d_secperunit - 1, believe the disk geometry. */
if (secperunit != 0 &&
disk_read_sectors(strat, lp, bp, secperunit - 1, 1) == 0)
geom_ok = 1;
else
geom_ok = 0;
#if 0
printf("%s: secperunit (%" PRIu32 ") %s\n", __func__,
secperunit, geom_ok ? "ok" : "not ok");
#endif
p = &lp->d_partitions[RAW_PART];
if (RAW_PART == 'c' - 'a')
altp = &lp->d_partitions['d' - 'a'];
else
altp = &lp->d_partitions['c' - 'a'];
if (lp->d_npartitions > RAW_PART && p->p_offset == 0 && p->p_size != 0)
return NULL; /* already a raw partition */
else if (lp->d_npartitions > MAX('c', 'd') - 'a' &&
altp->p_offset == 0 && altp->p_size != 0) {
/* alternate partition ('c' or 'd') is suitable for raw slot,
* swap with 'd' or 'c'.
*/
rp = *p;
*p = *altp;
*altp = rp;
return NULL;
} else if (lp->d_npartitions <= RAW_PART &&
lp->d_npartitions > 'c' - 'a') {
/* No raw partition is present, but the alternate is present.
* Copy alternate to raw partition.
*/
lp->d_npartitions = RAW_PART + 1;
*p = *altp;
return NULL;
} else if (!geom_ok)
str = "no raw partition and disk reports bad geometry";
else if (lp->d_npartitions <= RAW_PART) {
memset(&lp->d_partitions[lp->d_npartitions], 0,
sizeof(struct partition) * (RAW_PART - lp->d_npartitions));
*p = rp;
lp->d_npartitions = RAW_PART + 1;
return NULL;
} else if (lp->d_npartitions < MAXPARTITIONS) {
memmove(p + 1, p,
sizeof(struct partition) * (lp->d_npartitions - RAW_PART));
*p = rp;
lp->d_npartitions++;
return NULL;
} else
str = "no raw partition and partition table is full";
#ifdef DIAGNOSTIC
printf("Bad partition: %s\n", str);
printf("type = %u, subtype = %u, typename = %s\n",
lp->d_type, lp->d_subtype, lp->d_typename);
printf("secsize = %u, nsectors = %u, ntracks = %u\n",
lp->d_secsize, lp->d_nsectors, lp->d_ntracks);
printf("ncylinders = %u, secpercyl = %u, secperunit = %u\n",
lp->d_ncylinders, lp->d_secpercyl, lp->d_secperunit);
printf("npartitions = %u\n", lp->d_npartitions);
for (size_t i = 0; i < MIN(lp->d_npartitions, MAXPARTITIONS); i++) {
p = &lp->d_partitions[i];
printf("\t%c: offset = %u size = %u fstype = %u\n",
(char)(i + 'a'), p->p_offset, p->p_size, p->p_fstype);
}
#endif
return str;
}
int main(int argc, char *argv[])
{
struct part_iter *iter = NULL;
void *sbck = NULL;
struct data_area fdat, hdat, sdat, data[3];
int ndata = 0;
console_ansi_raw();
memset(&fdat, 0, sizeof fdat);
memset(&hdat, 0, sizeof hdat);
memset(&sdat, 0, sizeof sdat);
opt_set_defs();
if (opt_parse_args(argc, argv))
goto bail;
#if 0
/* Get max fixed disk number */
fixed_cnt = *(uint8_t *)(0x475);
/*
* hmm, looks like we can't do that -
* some bioses/vms just set it to 1
* and go on living happily
* any better options than hardcoded 0x80 - 0xFF ?
*/
#endif
/* Get disk/part iterator matching user supplied options */
if (find_dp(&iter))
goto bail;
/* Perform initial partition entry mangling */
if (manglepe_fixchs(iter))
goto bail;
if (manglepe_hide(iter))
goto bail;
/* Load the boot file */
if (opt.file) {
fdat.base = (opt.fseg << 4) + opt.foff;
if (loadfile(opt.file, &fdat.data, &fdat.size)) {
error("Couldn't read the boot file.");
goto bail;
}
if (fdat.base + fdat.size > dosmax) {
error("The boot file is too big to load at this address.");
goto bail;
}
}
/* Load the sector */
if (opt.sect) {
sdat.base = (opt.sseg << 4) + opt.soff;
sdat.size = iter->di.bps;
if (sdat.base + sdat.size > dosmax) {
error("The sector cannot be loaded at such high address.");
goto bail;
}
if (!(sdat.data = disk_read_sectors(&iter->di, iter->abs_lba, 1))) {
error("Couldn't read the sector.");
goto bail;
}
if (opt.save) {
if (!(sbck = malloc(sdat.size))) {
critm();
goto bail;
}
memcpy(sbck, sdat.data, sdat.size);
}
if (opt.file && opt.maps && overlap(&fdat, &sdat)) {
warn("The sector won't be mmapped, as it would conflict with the boot file.");
opt.maps = false;
}
}
/* Prep the handover */
if (opt.hand) {
if (setup_handover(iter, &hdat))
goto bail;
/* Verify possible conflicts */
if ( ( opt.file && overlap(&fdat, &hdat)) ||
( opt.maps && overlap(&sdat, &hdat)) ) {
warn("Handover area won't be prepared,\n"
"as it would conflict with the boot file and/or the sector.");
opt.hand = false;
}
}
/* Adjust registers */
mangler_init(iter);
mangler_handover(iter, &hdat);
mangler_grldr(iter);
/* Patching functions */
if (manglef_isolinux(&fdat))
goto bail;
if (manglef_grub(iter, &fdat))
goto bail;
#if 0
if (manglef_drmk(&fdat))
goto bail;
#endif
if (manglef_bpb(iter, &fdat))
goto bail;
if (mangles_bpb(iter, &sdat))
goto bail;
if (mangles_save(iter, &sdat, sbck))
goto bail;
if (manglesf_bss(&sdat, &fdat))
goto bail;
/* This *must* be after BPB saving or copying */
if (mangles_cmldr(&sdat))
goto bail;
/*
* Prepare boot-time mmap data. We should to it here, as manglers could
* potentially alter some of the data.
*/
if (opt.file)
memcpy(data + ndata++, &fdat, sizeof fdat);
if (opt.maps)
memcpy(data + ndata++, &sdat, sizeof sdat);
if (opt.hand)
memcpy(data + ndata++, &hdat, sizeof hdat);
#ifdef DEBUG
dprintf("iter->di dsk, bps: %X, %u\niter->di lbacnt, C*H*S: %"PRIu64", %u\n"
"iter->di C, H, S: %u, %u, %u\n",
iter->di.disk, iter->di.bps,
iter->di.lbacnt, iter->di.cyl * iter->di.head * iter->di.spt,
iter->di.cyl, iter->di.head, iter->di.spt);
dprintf("iter idx: %d\n", iter->index);
dprintf("iter lba: %"PRIu64"\n", iter->abs_lba);
if (opt.hand)
dprintf("hand lba: %u\n",
((struct disk_dos_part_entry *)hdat.data)->start_lba);
#endif
if (opt.warn) {
puts("Press any key to continue booting...");
wait_key();
}
if (ndata && !opt.brkchain) /* boot only if we actually chainload */
do_boot(data, ndata);
else
puts("Service-only run completed, exiting.");
bail:
pi_del(&iter);
/* Free allocated areas */
free(fdat.data);
free(sdat.data);
free(hdat.data);
free(sbck);
return 255;
}
/* pi_begin() - validate and and get proper iterator for a disk described by di */
struct part_iter *pi_begin(const struct disk_info *di, int flags)
{
int gptprot, ret = -1;
struct part_iter *iter;
struct disk_dos_mbr *mbr = NULL;
struct disk_gpt_header *gpth = NULL;
struct disk_gpt_part_entry *gptl = NULL;
/* Preallocate iterator */
if (!(iter = pi_alloc()))
goto bail;
/* Read MBR */
if (!(mbr = disk_read_sectors(di, 0, 1))) {
error("Couldn't read the first disk sector.");
goto bail;
}
/* Check for MBR magic */
if (mbr->sig != disk_mbr_sig_magic) {
warn("No MBR magic, treating disk as raw.");
/* looks like RAW */
ret = pi_ctor(iter, di, flags);
goto bail;
}
/* Check for GPT protective MBR */
gptprot = 0;
for (size_t i = 0; i < 4; i++)
gptprot |= (mbr->table[i].ostype == 0xEE);
if (gptprot && !(flags & PIF_PREFMBR)) {
if (!(gpth = disk_read_sectors(di, 1, 1))) {
error("Couldn't read potential GPT header.");
goto bail;
}
}
if (gpth && gpth->rev.uint32 == 0x00010000 &&
!memcmp(gpth->sig, disk_gpt_sig_magic, sizeof gpth->sig)) {
/* looks like GPT v1.0 */
uint64_t gpt_loff; /* offset to GPT partition list in sectors */
uint64_t gpt_lsiz; /* size of GPT partition list in bytes */
uint64_t gpt_lcnt; /* size of GPT partition in sectors */
#ifdef DEBUG
dprintf("Looks like a GPT v1.0 disk.\n");
disk_gpt_header_dump(gpth);
#endif
/* Verify checksum, fallback to backup, then bail if invalid */
if (gpt_check_hdr_crc(di, &gpth))
goto bail;
gpt_loff = gpth->lba_table;
gpt_lsiz = (uint64_t)gpth->part_size * gpth->part_count;
gpt_lcnt = (gpt_lsiz + di->bps - 1) / di->bps;
/*
* disk_read_sectors allows reading of max 255 sectors, so we use
* it as a sanity check base. EFI doesn't specify max (AFAIK).
* Apart from that, some extensive sanity checks.
*/
if (!(flags & PIF_RELAX) && (
!gpt_loff || !gpt_lsiz || gpt_lcnt > 255u ||
gpth->lba_first_usable > gpth->lba_last_usable ||
!sane(gpt_loff, gpt_lcnt) ||
gpt_loff + gpt_lcnt > gpth->lba_first_usable ||
!sane(gpth->lba_last_usable, gpt_lcnt) ||
gpth->lba_last_usable + gpt_lcnt >= gpth->lba_alt ||
gpth->lba_alt >= di->lbacnt ||
gpth->part_size < sizeof *gptl)) {
error("Invalid GPT header's values.");
goto bail;
}
if (!(gptl = disk_read_sectors(di, gpt_loff, gpt_lcnt))) {
error("Couldn't read GPT partition list.");
goto bail;
}
/* Check array checksum(s). */
if (!valid_crc(gpth->table_chksum, (const uint8_t *)gptl, (unsigned int)gpt_lsiz)) {
warn("Checksum of the main GPT partition list is invalid, trying backup.");
free(gptl);
/* secondary array directly precedes secondary header */
if (!(gptl = disk_read_sectors(di, gpth->lba_alt - gpt_lcnt, gpt_lcnt))) {
error("Couldn't read backup GPT partition list.");
goto bail;
}
if (!valid_crc(gpth->table_chksum, (const uint8_t *)gptl, gpt_lsiz)) {
error("Checksum of the backup GPT partition list is invalid, giving up.");
goto bail;
}
}
/* looks like GPT */
ret = pi_gpt_ctor(iter, di, flags, gpth, gptl);
} else {
/* looks like MBR */
ret = pi_dos_ctor(iter, di, flags, mbr);
}
bail:
if (ret < 0)
free(iter);
free(mbr);
free(gpth);
free(gptl);
return iter;
}
/*
* Attempt to read a disk label from a device
* using the indicated strategy routine.
* The label must be partly set up before this:
* secpercyl and anything required in the strategy routine
* (e.g., sector size) must be filled in before calling us.
* Returns null on success and an error string on failure.
*/
const char *
readdisklabel(dev_t dev, void (*strat)(struct buf *), struct disklabel *lp,
struct cpu_disklabel *clp)
{
struct buf *bp;
struct disklabel *dlp;
struct dkbad *bdp;
const char *msg = NULL;
uint32_t secperunit;
int i;
/* minimal requirements for archtypal disk label */
if (lp->d_secsize == 0)
lp->d_secsize = DEV_BSIZE;
if (lp->d_secperunit == 0)
lp->d_secperunit = 0x1fffffff;
lp->d_npartitions = RAW_PART + 1;
if (lp->d_partitions[RAW_PART].p_size == 0)
lp->d_partitions[RAW_PART].p_size = lp->d_secperunit;
lp->d_partitions[RAW_PART].p_offset = 0;
secperunit = lp->d_secperunit;
/* obtain buffer to probe drive with */
bp = geteblk((int)lp->d_secsize);
bp->b_dev = dev;
/* Next, dig out disk label. If successful, locate disk
* label within block and validate.
*/
if (disk_read_sectors(strat, lp, bp, LABELSECTOR, 1) != 0) {
msg = "disk label read error";
goto done;
}
for (dlp = (struct disklabel *)bp->b_data;
dlp <= (struct disklabel *)((char *)bp->b_data + lp->d_secsize -
sizeof(*dlp));
dlp = (struct disklabel *)((char *)dlp + sizeof(long))) {
if (dlp->d_magic != DISKMAGIC || dlp->d_magic2 != DISKMAGIC) {
if (msg == NULL)
msg = "no disk label";
} else if (dlp->d_npartitions > MAXPARTITIONS ||
dkcksum(dlp) != 0)
msg = "disk label corrupted";
else {
*lp = *dlp;
msg = NULL;
break;
}
}
if (msg)
goto done;
if ((msg = convertdisklabel(lp, strat, bp, secperunit)) != NULL)
goto done;
/* obtain bad sector table if requested and present */
if (clp && (bdp = &clp->bad) != NULL && (lp->d_flags & D_BADSECT)) {
struct dkbad *db;
i = 0;
do {
/* read a bad sector table */
bp->b_oflags &= ~(BO_DONE);
bp->b_flags |= B_READ;
bp->b_blkno = lp->d_secperunit - lp->d_nsectors + i;
if (lp->d_secsize > DEV_BSIZE)
bp->b_blkno *= lp->d_secsize / DEV_BSIZE;
else
bp->b_blkno /= DEV_BSIZE / lp->d_secsize;
bp->b_bcount = lp->d_secsize;
bp->b_cylinder = lp->d_ncylinders - 1;
(*strat)(bp);
/* if successful, validate, otherwise try another */
if (biowait(bp)) {
msg = "bad sector table I/O error";
} else {
db = (struct dkbad *)(bp->b_data);
#define DKBAD_MAGIC 0x4321
if (db->bt_mbz == 0
&& db->bt_flag == DKBAD_MAGIC) {
msg = NULL;
*bdp = *db;
break;
} else
msg = "bad sector table corrupted";
}
} while (bp->b_error != 0 && (i += 2) < 10 &&
i < lp->d_nsectors);
}
done:
brelse(bp, 0);
return (msg);
}
/* pi_begin() - validate and and get proper iterator for a disk described by di */
struct part_iter *pi_begin(const struct disk_info *di, int flags)
{
int isgpt = 0, ret = -1;
struct part_iter *iter;
struct disk_dos_mbr *mbr = NULL;
struct disk_gpt_header *gpth = NULL;
struct disk_gpt_part_entry *gptl = NULL;
/* Preallocate iterator */
if (!(iter = pi_alloc()))
goto out;
/* Read MBR */
if (!(mbr = disk_read_sectors(di, 0, 1))) {
error("Unable to read the first disk sector.");
goto out;
}
/* Check for MBR magic */
if (mbr->sig != disk_mbr_sig_magic) {
warn("No MBR magic, treating disk as raw.");
/* looks like RAW */
ret = pi_ctor(iter, di, flags);
goto out;
}
/* Check for GPT protective MBR */
for (size_t i = 0; i < 4; i++)
isgpt |= (mbr->table[i].ostype == 0xEE);
isgpt = isgpt && !(flags & PIF_PREFMBR);
/* Try to read GPT header */
if (isgpt) {
gpth = try_gpt_hdr(di, 0);
if (!gpth)
/*
* this read might fail if bios reports different disk size (different vm/pc)
* not much we can do here to avoid it
*/
gpth = try_gpt_hdr(di, 1);
if (!gpth)
goto out;
}
if (gpth && gpth->rev.uint32 == 0x00010000 &&
!memcmp(gpth->sig, disk_gpt_sig_magic, sizeof gpth->sig)) {
/* looks like GPT v1.0 */
#ifdef DEBUG
dprintf("Looks like a GPT v1.0 disk.\n");
disk_gpt_header_dump(gpth);
#endif
if (notsane_gpt_hdr(di, gpth, flags)) {
error("GPT header values are corrupted.");
goto out;
}
gptl = try_gpt_list(di, gpth, 0);
if (!gptl)
gptl = try_gpt_list(di, gpth, 1);
if (!gptl)
goto out;
/* looks like GPT */
ret = pi_gpt_ctor(iter, di, flags, gpth, gptl);
} else {
/* looks like MBR */
ret = pi_dos_ctor(iter, di, flags, mbr);
}
out:
if (ret < 0) {
free(iter);
iter = NULL;
}
free(mbr);
free(gpth);
free(gptl);
return iter;
}
const char *
convertdisklabel(struct disklabel *lp, void (*strat)(struct buf *),
struct buf *bp, uint32_t secperunit)
{
struct partition rp, *altp, *p;
int geom_ok;
memset(&rp, 0, sizeof(rp));
rp.p_size = secperunit;
rp.p_fstype = FS_UNUSED;
/* If we can seek to d_secperunit - 1, believe the disk geometry. */
if (secperunit != 0 &&
disk_read_sectors(strat, lp, bp, secperunit - 1, 1) == 0)
geom_ok = 1;
else
geom_ok = 0;
#if 0
printf("%s: secperunit (%" PRIu32 ") %s\n", __func__,
secperunit, geom_ok ? "ok" : "not ok");
#endif
p = &lp->d_partitions[RAW_PART];
if (RAW_PART == 'c' - 'a')
altp = &lp->d_partitions['d' - 'a'];
else
altp = &lp->d_partitions['c' - 'a'];
if (lp->d_npartitions > RAW_PART && p->p_offset == 0 && p->p_size != 0)
; /* already a raw partition */
else if (lp->d_npartitions > MAX('c', 'd') - 'a' &&
altp->p_offset == 0 && altp->p_size != 0) {
/* alternate partition ('c' or 'd') is suitable for raw slot,
* swap with 'd' or 'c'.
*/
rp = *p;
*p = *altp;
*altp = rp;
} else if (lp->d_npartitions <= RAW_PART &&
lp->d_npartitions > 'c' - 'a') {
/* No raw partition is present, but the alternate is present.
* Copy alternate to raw partition.
*/
lp->d_npartitions = RAW_PART + 1;
*p = *altp;
} else if (!geom_ok)
return "no raw partition and disk reports bad geometry";
else if (lp->d_npartitions <= RAW_PART) {
memset(&lp->d_partitions[lp->d_npartitions], 0,
sizeof(struct partition) * (RAW_PART - lp->d_npartitions));
*p = rp;
lp->d_npartitions = RAW_PART + 1;
} else if (lp->d_npartitions < MAXPARTITIONS) {
memmove(p + 1, p,
sizeof(struct partition) * (lp->d_npartitions - RAW_PART));
*p = rp;
lp->d_npartitions++;
} else
return "no raw partition and partition table is full";
return NULL;
}
ssize_t hd_read(minor_t minor, lbaint_t lba_start, lbaint_t count, void* buffer)
{
ssize_t read = 0;
CHS_t chs_addr_start;
chs_disk_geometry_t* dev_info = (chs_disk_geometry_t*) hd_getinfo(minor);
assert(dev_info != NULL);
// check that the number of sectors per track is not greated than what I can write in a real mode segment
assert(dev_info->NS <= (SEGMENT_SIZE_16bit_MODE / SECTOR_SIZE));
// check parameters
assert(lba_start < dev_info->Nlba);
assert(lba_start + count <= dev_info->Nlba);
uint16_t buf_rm_segment;
uint16_t buf_rm_offset;
#ifdef BOOTLOADER_PROTECTED_MODE_ENABLED
buf_rm_segment = SEGMENT_EXTRA_DATA_RM;
buf_rm_offset = 0x0000;
#else
reg_get_data_segment(&buf_rm_segment);
buf_rm_offset = (uint16_t)(uint32_t)buffer;
#endif
uint8_t nb_sectors_to_read = count;
while (count > 0) {
// convert LBA address to CHS address
lbatochs(dev_info, lba_start, &chs_addr_start);
#ifdef DEBUG_HD_DRIVER
debug_printf("hd(%u,%u): req READ (lba_start = %u <=> CHS=(%u,%u,%u), count = %u)\r\n",
HARD_DISK_DRIVER, minor, lba_start,
chs_addr_start.C, chs_addr_start.H, chs_addr_start.S, count);
#endif
// check track bounds
if (count > dev_info->NS) {
nb_sectors_to_read = dev_info->NS - chs_addr_start.S + 1;
#ifdef DEBUG_HD_DRIVER
debug_printf("hd(%u,%u): resize req to (lba_start = %u, count = %u)\r\n",
HARD_DISK_DRIVER, minor, lba_start, nb_sectors_to_read);
#endif
}
#ifdef DEBUG_HD_DRIVER
debug_printf("hd(%u,%u): [bios] disk %#02x, attempt to read %u sectors",
HARD_DISK_DRIVER, minor, BIOS_HD_DRIVE_BASE_NB + minor, nb_sectors_to_read);
#endif
uint8_t nb_read_sectors = 0;
for (uint8_t i=0; i<5 && (nb_read_sectors != nb_sectors_to_read); i++) {
nb_read_sectors = disk_read_sectors(BIOS_HD_DRIVE_BASE_NB + minor, buf_rm_segment, buf_rm_offset, &chs_addr_start, nb_sectors_to_read);
}
#ifdef DEBUG_HD_DRIVER
if (nb_read_sectors != nb_sectors_to_read) {
debug_printf(", read %u sectors [NOK]\r\n", nb_read_sectors);
} else {
debug_printf(" [OK]\r\n");
}
#endif
size_t nb_read_bytes = nb_read_sectors * SECTOR_SIZE;
#ifdef BOOTLOADER_PROTECTED_MODE_ENABLED
// copy data to buffer
memcpy(buffer, (void*)(buf_rm_segment << 4 | buf_rm_offset), nb_read_bytes);
buf_rm_offset = 0x0000;
#else
buf_rm_offset += nb_read_bytes;
#endif
read += nb_read_bytes;
count -= nb_read_sectors;
lba_start += nb_read_sectors;
}
return read;
}
