Initial variable sector size support

This commit is contained in:
Vladimir 'phcoder' Serbinenko 2011-03-29 02:02:55 +02:00
parent f329eda79e
commit 09573499ff
7 changed files with 155 additions and 96 deletions

View File

@ -536,8 +536,13 @@ grub_efidisk_open (const char *name, struct grub_disk *disk)
and total sectors should be replaced with total blocks. */
grub_dprintf ("efidisk", "m = %p, last block = %llx, block size = %x\n",
m, (unsigned long long) m->last_block, m->block_size);
disk->total_sectors = (m->last_block
* (m->block_size >> GRUB_DISK_SECTOR_BITS));
disk->total_sectors = m->last_block;
if (m->blocksize & (m->blocksize - 1) || !m->blocksize)
return grub_error (GRUB_ERR_IO, "invalid sector size %d",
m->blocksize);
for (disk->log_sector_size = 0;
(1 << disk->log_sector_size) < m->blocksize;
disk->log_sector_size++);
disk->data = d;
grub_dprintf ("efidisk", "opening %s succeeded\n", name);
@ -571,8 +576,8 @@ grub_efidisk_read (struct grub_disk *disk, grub_disk_addr_t sector,
(unsigned long) size, (unsigned long long) sector, disk->name);
status = efi_call_5 (dio->read, dio, bio->media->media_id,
(grub_efi_uint64_t) sector << GRUB_DISK_SECTOR_BITS,
(grub_efi_uintn_t) size << GRUB_DISK_SECTOR_BITS,
(grub_efi_uint64_t) sector << disk->log_sector_size,
(grub_efi_uintn_t) size << disk->log_sector_size,
buf);
if (status != GRUB_EFI_SUCCESS)
return grub_error (GRUB_ERR_READ_ERROR, "efidisk read error");
@ -599,8 +604,8 @@ grub_efidisk_write (struct grub_disk *disk, grub_disk_addr_t sector,
(unsigned long) size, (unsigned long long) sector, disk->name);
status = efi_call_5 (dio->write, dio, bio->media->media_id,
(grub_efi_uint64_t) sector << GRUB_DISK_SECTOR_BITS,
(grub_efi_uintn_t) size << GRUB_DISK_SECTOR_BITS,
(grub_efi_uint64_t) sector << disk->log_sector_size,
(grub_efi_uintn_t) size << disk->log_sector_size,
(void *) buf);
if (status != GRUB_EFI_SUCCESS)
return grub_error (GRUB_ERR_WRITE_ERROR, "efidisk write error");

View File

@ -338,7 +338,8 @@ grub_biosdisk_open (const char *name, grub_disk_t disk)
if ((cd_drive) && (drive == cd_drive))
{
data->flags = GRUB_BIOSDISK_FLAG_LBA | GRUB_BIOSDISK_FLAG_CDROM;
data->sectors = 32;
data->sectors = 8;
disk->log_sector_size = 11;
/* TODO: get the correct size. */
total_sectors = GRUB_DISK_SIZE_UNKNOWN;
}
@ -347,6 +348,8 @@ grub_biosdisk_open (const char *name, grub_disk_t disk)
/* HDD */
int version;
disk->log_sector_size = 9;
version = grub_biosdisk_check_int13_extensions (drive);
if (version)
{
@ -367,6 +370,15 @@ grub_biosdisk_open (const char *name, grub_disk_t disk)
correctly but returns zero. So if it is zero, compute
it by C/H/S returned by the LBA BIOS call. */
total_sectors = drp->cylinders * drp->heads * drp->sectors;
if (drp->bytes_per_sector
&& !(drp->bytes_per_sector & (drp->bytes_per_sector - 1))
&& drp->bytes_per_sector >= 512
&& drp->bytes_per_sector <= 16384)
{
for (disk->log_sector_size = 0;
(1 << disk->log_sector_size) < drp->bytes_per_sector;
disk->log_sector_size++);
}
}
}
}
@ -429,7 +441,7 @@ grub_biosdisk_rw (int cmd, grub_disk_t disk,
dap = (struct grub_biosdisk_dap *) (GRUB_MEMORY_MACHINE_SCRATCH_ADDR
+ (data->sectors
<< GRUB_DISK_SECTOR_BITS));
<< disk->log_sector_size));
dap->length = sizeof (*dap);
dap->reserved = 0;
dap->blocks = size;
@ -443,9 +455,6 @@ grub_biosdisk_rw (int cmd, grub_disk_t disk,
if (cmd)
return grub_error (GRUB_ERR_WRITE_ERROR, "can\'t write to cdrom");
dap->blocks = ALIGN_UP (dap->blocks, 4) >> 2;
dap->block >>= 2;
for (i = 0; i < GRUB_BIOSDISK_CDROM_RETRY_COUNT; i++)
if (! grub_biosdisk_rw_int13_extensions (0x42, data->drive, dap))
break;
@ -501,10 +510,12 @@ grub_biosdisk_rw (int cmd, grub_disk_t disk,
/* Return the number of sectors which can be read safely at a time. */
static grub_size_t
get_safe_sectors (grub_disk_addr_t sector, grub_uint32_t sectors)
get_safe_sectors (grub_disk_t disk, grub_disk_addr_t sector)
{
grub_size_t size;
grub_uint32_t offset;
struct grub_biosdisk_data *data = disk->data;
grub_uint32_t sectors = data->sectors;
/* OFFSET = SECTOR % SECTORS */
grub_divmod64 (sector, sectors, &offset);
@ -512,8 +523,8 @@ get_safe_sectors (grub_disk_addr_t sector, grub_uint32_t sectors)
size = sectors - offset;
/* Limit the max to 0x7f because of Phoenix EDD. */
if (size > 0x7f)
size = 0x7f;
if (size > ((0x7fU << GRUB_DISK_SECTOR_BITS) >> disk->log_sector_size))
size = ((0x7fU << GRUB_DISK_SECTOR_BITS) >> disk->log_sector_size);
return size;
}
@ -522,21 +533,11 @@ static grub_err_t
grub_biosdisk_read (grub_disk_t disk, grub_disk_addr_t sector,
grub_size_t size, char *buf)
{
struct grub_biosdisk_data *data = disk->data;
while (size)
{
grub_size_t len;
grub_size_t cdoff = 0;
len = get_safe_sectors (sector, data->sectors);
if (data->flags & GRUB_BIOSDISK_FLAG_CDROM)
{
cdoff = (sector & 3) << GRUB_DISK_SECTOR_BITS;
len = ALIGN_UP (sector + len, 4) - (sector & ~3);
sector &= ~3;
}
len = get_safe_sectors (disk, sector);
if (len > size)
len = size;
@ -545,9 +546,10 @@ grub_biosdisk_read (grub_disk_t disk, grub_disk_addr_t sector,
GRUB_MEMORY_MACHINE_SCRATCH_SEG))
return grub_errno;
grub_memcpy (buf, (void *) (GRUB_MEMORY_MACHINE_SCRATCH_ADDR + cdoff),
len << GRUB_DISK_SECTOR_BITS);
buf += len << GRUB_DISK_SECTOR_BITS;
grub_memcpy (buf, (void *) GRUB_MEMORY_MACHINE_SCRATCH_ADDR,
len << disk->log_sector_size);
buf += len << disk->log_sector_size;
sector += len;
size -= len;
}
@ -568,18 +570,18 @@ grub_biosdisk_write (grub_disk_t disk, grub_disk_addr_t sector,
{
grub_size_t len;
len = get_safe_sectors (sector, data->sectors);
len = get_safe_sectors (disk, sector);
if (len > size)
len = size;
grub_memcpy ((void *) GRUB_MEMORY_MACHINE_SCRATCH_ADDR, buf,
len << GRUB_DISK_SECTOR_BITS);
len << disk->log_sector_size);
if (grub_biosdisk_rw (GRUB_BIOSDISK_WRITE, disk, sector, len,
GRUB_MEMORY_MACHINE_SCRATCH_SEG))
return grub_errno;
buf += len << GRUB_DISK_SECTOR_BITS;
buf += len << disk->log_sector_size;
sector += len;
size -= len;
}

View File

@ -463,15 +463,20 @@ grub_scsi_open (const char *name, grub_disk_t disk)
return err;
}
/* SCSI blocks can be something else than 512, although GRUB
wants 512 byte blocks. */
disk->total_sectors = ((grub_uint64_t)scsi->size
* (grub_uint64_t)scsi->blocksize)
>> GRUB_DISK_SECTOR_BITS;
disk->total_sectors = scsi->size;
if (scsi->blocksize & (scsi->blocksize - 1) || !scsi->blocksize)
{
grub_free (scsi);
return grub_error (GRUB_ERR_IO, "invalid sector size %d",
scsi->blocksize);
}
for (disk->log_sector_size = 0;
(1 << disk->log_sector_size) < scsi->blocksize;
disk->log_sector_size++);
grub_dprintf ("scsi", "blocks=%u, blocksize=%u\n",
scsi->size, scsi->blocksize);
grub_dprintf ("scsi", "Disk total 512 sectors = %llu\n",
grub_dprintf ("scsi", "Disk total sectors = %llu\n",
(unsigned long long) disk->total_sectors);
return GRUB_ERR_NONE;
@ -501,25 +506,6 @@ grub_scsi_read (grub_disk_t disk, grub_disk_addr_t sector,
scsi = disk->data;
/* SCSI sectors are variable in size. GRUB uses 512 byte
sectors. */
if (scsi->blocksize != GRUB_DISK_SECTOR_SIZE)
{
unsigned spb = scsi->blocksize >> GRUB_DISK_SECTOR_BITS;
if (spb == 0 || (scsi->blocksize & (GRUB_DISK_SECTOR_SIZE - 1)) != 0)
return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
"unsupported SCSI block size");
grub_uint32_t sector_mod = 0;
sector = grub_divmod64 (sector, spb, &sector_mod);
if (! (sector_mod == 0 && size % spb == 0))
return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
"unaligned SCSI read not supported");
size /= spb;
}
/* Depending on the type, select a read function. */
switch (scsi->devtype)
{

View File

@ -247,6 +247,7 @@ grub_disk_open (const char *name)
disk = (grub_disk_t) grub_zalloc (sizeof (*disk));
if (! disk)
return 0;
disk->log_sector_size = GRUB_DISK_SECTOR_BITS;
p = find_part_sep (name);
if (p)
@ -266,7 +267,6 @@ grub_disk_open (const char *name)
if (! disk->name)
goto fail;
for (dev = grub_disk_dev_list; dev; dev = dev->next)
{
if ((dev->open) (raw, disk) == GRUB_ERR_NONE)
@ -282,6 +282,14 @@ grub_disk_open (const char *name)
grub_error (GRUB_ERR_UNKNOWN_DEVICE, "no such disk");
goto fail;
}
if (disk->log_sector_size > GRUB_DISK_CACHE_BITS + GRUB_DISK_SECTOR_BITS
|| disk->log_sector_size < GRUB_DISK_SECTOR_BITS)
{
grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
"sector sizes of %d bytes aren't supported yet",
(1 << disk->log_sector_size));
goto fail;
}
disk->dev = dev;
@ -373,14 +381,23 @@ grub_disk_adjust_range (grub_disk_t disk, grub_disk_addr_t *sector,
*sector += start;
}
if (disk->total_sectors <= *sector
|| ((*offset + size + GRUB_DISK_SECTOR_SIZE - 1)
>> GRUB_DISK_SECTOR_BITS) > disk->total_sectors - *sector)
if (disk->total_sectors != GRUB_DISK_SIZE_UNKNOWN
&& ((disk->total_sectors << (disk->log_sector_size - GRUB_DISK_SECTOR_BITS)) <= *sector
|| ((*offset + size + GRUB_DISK_SECTOR_SIZE - 1)
>> GRUB_DISK_SECTOR_BITS) > (disk->total_sectors
<< (disk->log_sector_size
- GRUB_DISK_SECTOR_BITS)) - *sector))
return grub_error (GRUB_ERR_OUT_OF_RANGE, "out of disk");
return GRUB_ERR_NONE;
}
static inline grub_disk_addr_t
transform_sector (grub_disk_t disk, grub_disk_addr_t sector)
{
return sector >> (disk->log_sector_size - GRUB_DISK_SECTOR_BITS);
}
/* Read data from the disk. */
grub_err_t
grub_disk_read (grub_disk_t disk, grub_disk_addr_t sector,
@ -433,27 +450,39 @@ grub_disk_read (grub_disk_t disk, grub_disk_addr_t sector,
else
{
/* Otherwise read data from the disk actually. */
if (start_sector + GRUB_DISK_CACHE_SIZE > disk->total_sectors
|| (disk->dev->read) (disk, start_sector,
GRUB_DISK_CACHE_SIZE, tmp_buf)
if ((disk->total_sectors != GRUB_DISK_SIZE_UNKNOWN
&& start_sector + GRUB_DISK_CACHE_SIZE
> (disk->total_sectors << (disk->log_sector_size - GRUB_DISK_SECTOR_BITS)))
|| (disk->dev->read) (disk, transform_sector (disk, start_sector),
1 << (GRUB_DISK_CACHE_BITS
+ GRUB_DISK_SECTOR_BITS
- disk->log_sector_size), tmp_buf)
!= GRUB_ERR_NONE)
{
/* Uggh... Failed. Instead, just read necessary data. */
unsigned num;
char *p;
grub_disk_addr_t aligned_sector;
grub_errno = GRUB_ERR_NONE;
num = ((size + real_offset + GRUB_DISK_SECTOR_SIZE - 1)
>> GRUB_DISK_SECTOR_BITS);
aligned_sector = (sector & ~((1 << (disk->log_sector_size
- GRUB_DISK_SECTOR_BITS))
- 1));
real_offset += ((sector - aligned_sector)
<< GRUB_DISK_SECTOR_BITS);
num = ((size + real_offset + (1 << (disk->log_sector_size))
- 1) >> (disk->log_sector_size));
p = grub_realloc (tmp_buf, num << GRUB_DISK_SECTOR_BITS);
p = grub_realloc (tmp_buf, num << disk->log_sector_size);
if (!p)
goto finish;
tmp_buf = p;
if ((disk->dev->read) (disk, sector, num, tmp_buf))
if ((disk->dev->read) (disk, transform_sector (disk,
aligned_sector),
num, tmp_buf))
{
grub_error_push ();
grub_dprintf ("disk", "%s read failed\n", disk->name);
@ -528,25 +557,31 @@ grub_disk_write (grub_disk_t disk, grub_disk_addr_t sector,
grub_off_t offset, grub_size_t size, const void *buf)
{
unsigned real_offset;
grub_disk_addr_t aligned_sector;
grub_dprintf ("disk", "Writing `%s'...\n", disk->name);
if (grub_disk_adjust_range (disk, &sector, &offset, size) != GRUB_ERR_NONE)
return -1;
real_offset = offset;
aligned_sector = (sector & ~((1 << (disk->log_sector_size
- GRUB_DISK_SECTOR_BITS)) - 1));
real_offset = offset + ((sector - aligned_sector) << GRUB_DISK_SECTOR_BITS);
sector = aligned_sector;
while (size)
{
if (real_offset != 0 || (size < GRUB_DISK_SECTOR_SIZE && size != 0))
if (real_offset != 0 || (size < (1U << disk->log_sector_size)
&& size != 0))
{
char tmp_buf[GRUB_DISK_SECTOR_SIZE];
char tmp_buf[1 << disk->log_sector_size];
grub_size_t len;
grub_partition_t part;
part = disk->partition;
disk->partition = 0;
if (grub_disk_read (disk, sector, 0, GRUB_DISK_SECTOR_SIZE, tmp_buf)
if (grub_disk_read (disk, sector,
0, (1 << disk->log_sector_size), tmp_buf)
!= GRUB_ERR_NONE)
{
disk->partition = part;
@ -554,7 +589,7 @@ grub_disk_write (grub_disk_t disk, grub_disk_addr_t sector,
}
disk->partition = part;
len = GRUB_DISK_SECTOR_SIZE - real_offset;
len = (1 << disk->log_sector_size) - real_offset;
if (len > size)
len = size;
@ -565,7 +600,7 @@ grub_disk_write (grub_disk_t disk, grub_disk_addr_t sector,
if ((disk->dev->write) (disk, sector, 1, tmp_buf) != GRUB_ERR_NONE)
goto finish;
sector++;
sector += (1 << (disk->log_sector_size - GRUB_DISK_SECTOR_BITS));
buf = (char *) buf + len;
size -= len;
real_offset = 0;
@ -575,8 +610,8 @@ grub_disk_write (grub_disk_t disk, grub_disk_addr_t sector,
grub_size_t len;
grub_size_t n;
len = size & ~(GRUB_DISK_SECTOR_SIZE - 1);
n = size >> GRUB_DISK_SECTOR_BITS;
len = size & ~((1 << disk->log_sector_size) - 1);
n = size >> disk->log_sector_size;
if ((disk->dev->write) (disk, sector, n, buf) != GRUB_ERR_NONE)
goto finish;
@ -599,6 +634,8 @@ grub_disk_get_size (grub_disk_t disk)
{
if (disk->partition)
return grub_partition_get_len (disk->partition);
else if (disk->total_sectors != GRUB_DISK_SIZE_UNKNOWN)
return disk->total_sectors << (disk->log_sector_size - GRUB_DISK_SECTOR_BITS);
else
return disk->total_sectors;
return GRUB_DISK_SIZE_UNKNOWN;
}

View File

@ -42,6 +42,7 @@
#ifdef __linux__
# include <sys/ioctl.h> /* ioctl */
# include <sys/mount.h>
# if !defined(__GLIBC__) || \
((__GLIBC__ < 2) || ((__GLIBC__ == 2) && (__GLIBC_MINOR__ < 1)))
/* Maybe libc doesn't have large file support. */
@ -264,6 +265,7 @@ grub_util_biosdisk_open (const char *name, grub_disk_t disk)
# else
unsigned long long nr;
# endif
int sector_size;
int fd;
fd = open (map[drive].device, O_RDONLY);
@ -295,16 +297,28 @@ grub_util_biosdisk_open (const char *name, grub_disk_t disk)
goto fail;
}
if (ioctl (fd, BLKSSZGET, &sector_size))
{
close (fd);
goto fail;
}
close (fd);
if (sector_size & (sector_size - 1) || !sector_size)
goto fail;
for (disk->log_sector_size = 0;
(1 << disk->log_sector_size) < sector_size;
disk->log_sector_size++);
# if defined (__APPLE__)
disk->total_sectors = nr;
# elif defined(__NetBSD__)
disk->total_sectors = label.d_secperunit;
# else
disk->total_sectors = nr / 512;
disk->total_sectors = nr >> disk->log_sector_size;
if (nr % 512)
if (nr & ((1 << disk->log_sector_size) - 1))
grub_util_error ("unaligned device size");
# endif
@ -321,7 +335,7 @@ grub_util_biosdisk_open (const char *name, grub_disk_t disk)
if (stat (map[drive].device, &st) < 0)
return grub_error (GRUB_ERR_UNKNOWN_DEVICE, "cannot stat `%s'", map[drive].device);
disk->total_sectors = st.st_size >> GRUB_DISK_SECTOR_BITS;
disk->total_sectors = st.st_size >> disk->log_sector_size;
grub_util_info ("the size of %s is %lu", name, disk->total_sectors);
@ -760,7 +774,7 @@ open_device (const grub_disk_t disk, grub_disk_addr_t sector, int flags)
_syscall5 (int, _llseek, uint, filedes, ulong, hi, ulong, lo,
loff_t *, res, uint, wh);
offset = (loff_t) sector << GRUB_DISK_SECTOR_BITS;
offset = (loff_t) sector << disk->log_sector_size;
if (_llseek (fd, offset >> 32, offset & 0xffffffff, &result, SEEK_SET))
{
grub_error (GRUB_ERR_BAD_DEVICE, "cannot seek `%s'", map[disk->id].device);
@ -770,7 +784,7 @@ open_device (const grub_disk_t disk, grub_disk_addr_t sector, int flags)
}
#else
{
off_t offset = (off_t) sector << GRUB_DISK_SECTOR_BITS;
off_t offset = (off_t) sector << disk->log_sector_size;
if (lseek (fd, offset, SEEK_SET) != offset)
{
@ -870,20 +884,21 @@ grub_util_biosdisk_read (grub_disk_t disk, grub_disk_addr_t sector,
sectors that are read together with the MBR in one read. It
should only remap the MBR, so we split the read in two
parts. -jochen */
if (nread (fd, buf, GRUB_DISK_SECTOR_SIZE) != GRUB_DISK_SECTOR_SIZE)
if (nread (fd, buf, (1 << disk->log_sector_size))
!= (1 << disk->log_sector_size))
{
grub_error (GRUB_ERR_READ_ERROR, "cannot read `%s'", map[disk->id].device);
close (fd);
return grub_errno;
}
buf += GRUB_DISK_SECTOR_SIZE;
buf += (1 << disk->log_sector_size);
size--;
}
#endif /* __linux__ */
if (nread (fd, buf, size << GRUB_DISK_SECTOR_BITS)
!= (ssize_t) (size << GRUB_DISK_SECTOR_BITS))
if (nread (fd, buf, size << disk->log_sector_size)
!= (ssize_t) (size << disk->log_sector_size))
grub_error (GRUB_ERR_READ_ERROR, "cannot read from `%s'", map[disk->id].device);
return grub_errno;
@ -916,8 +931,8 @@ grub_util_biosdisk_write (grub_disk_t disk, grub_disk_addr_t sector,
if (fd < 0)
return grub_errno;
if (nwrite (fd, buf, size << GRUB_DISK_SECTOR_BITS)
!= (ssize_t) (size << GRUB_DISK_SECTOR_BITS))
if (nwrite (fd, buf, size << disk->log_sector_size)
!= (ssize_t) (size << disk->log_sector_size))
grub_error (GRUB_ERR_WRITE_ERROR, "cannot write to `%s'", map[disk->id].device);
return grub_errno;

View File

@ -90,8 +90,11 @@ grub_partition_msdos_iterate (grub_disk_t disk,
{
e = mbr.entries + p.index;
p.start = p.offset + grub_le_to_cpu32 (e->start) - delta;
p.len = grub_le_to_cpu32 (e->length);
p.start = p.offset
+ (grub_le_to_cpu32 (e->start)
<< (disk->log_sector_size - GRUB_DISK_SECTOR_BITS)) - delta;
p.len = grub_le_to_cpu32 (e->length)
<< (disk->log_sector_size - GRUB_DISK_SECTOR_BITS);
p.msdostype = e->type;
grub_dprintf ("partition",
@ -126,7 +129,9 @@ grub_partition_msdos_iterate (grub_disk_t disk,
if (grub_msdos_partition_is_extended (e->type))
{
p.offset = ext_offset + grub_le_to_cpu32 (e->start);
p.offset = ext_offset
+ (grub_le_to_cpu32 (e->start)
<< (disk->log_sector_size - GRUB_DISK_SECTOR_BITS));
if (! ext_offset)
ext_offset = p.offset;
@ -204,8 +209,11 @@ pc_partition_map_embed (struct grub_disk *disk, unsigned int *nsectors,
e = mbr.entries + i;
if (!grub_msdos_partition_is_empty (e->type)
&& end > offset + grub_le_to_cpu32 (e->start))
end = offset + grub_le_to_cpu32 (e->start);
&& end > offset
+ (grub_le_to_cpu32 (e->start)
<< (disk->log_sector_size - GRUB_DISK_SECTOR_BITS)))
end = offset + (grub_le_to_cpu32 (e->start)
<< (disk->log_sector_size - GRUB_DISK_SECTOR_BITS));
/* If this is a GPT partition, this MBR is just a dummy. */
if (e->type == GRUB_PC_PARTITION_TYPE_GPT_DISK && i == 0)
@ -219,7 +227,9 @@ pc_partition_map_embed (struct grub_disk *disk, unsigned int *nsectors,
if (grub_msdos_partition_is_extended (e->type))
{
offset = ext_offset + grub_le_to_cpu32 (e->start);
offset = ext_offset
+ (grub_le_to_cpu32 (e->start)
<< (disk->log_sector_size - GRUB_DISK_SECTOR_BITS));
if (! ext_offset)
ext_offset = offset;

View File

@ -100,6 +100,9 @@ struct grub_disk
/* The total number of sectors. */
grub_uint64_t total_sectors;
/* Logarithm of sector size. */
unsigned int log_sector_size;
/* The id used by the disk cache manager. */
unsigned long id;
@ -132,9 +135,10 @@ typedef struct grub_disk_memberlist *grub_disk_memberlist_t;
/* The maximum number of disk caches. */
#define GRUB_DISK_CACHE_NUM 1021
/* The size of a disk cache in sector units. */
#define GRUB_DISK_CACHE_SIZE 8
#define GRUB_DISK_CACHE_BITS 3
/* The size of a disk cache in 512B units. Must be at least as big as the
largest supported sector size, currently 16K. */
#define GRUB_DISK_CACHE_BITS 6
#define GRUB_DISK_CACHE_SIZE (1 << GRUB_DISK_CACHE_BITS)
/* Return value of grub_disk_get_size() in case disk size is unknown. */
#define GRUB_DISK_SIZE_UNKNOWN 0xffffffffffffffffULL