455 lines
11 KiB
C
455 lines
11 KiB
C
/*
|
|
* GRUB -- GRand Unified Bootloader
|
|
* Copyright (C) 1999,2000,2001,2002,2003,2004,2005,2006,2007,2008 Free Software Foundation, Inc.
|
|
*
|
|
* GRUB is free software: you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation, either version 3 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* GRUB is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#include <grub/machine/biosdisk.h>
|
|
#include <grub/machine/memory.h>
|
|
#include <grub/machine/kernel.h>
|
|
#include <grub/machine/int.h>
|
|
#include <grub/disk.h>
|
|
#include <grub/dl.h>
|
|
#include <grub/mm.h>
|
|
#include <grub/types.h>
|
|
#include <grub/misc.h>
|
|
#include <grub/err.h>
|
|
#include <grub/term.h>
|
|
|
|
static int cd_drive = 0;
|
|
static int grub_biosdisk_rw_int13_extensions (int ah, int drive, void *dap);
|
|
|
|
static int grub_biosdisk_get_num_floppies (void)
|
|
{
|
|
struct grub_cpu_int_registers regs;
|
|
int drive;
|
|
|
|
/* reset the disk system first */
|
|
regs.ax = 0;
|
|
regs.dx = 0;
|
|
regs.flags = GRUB_CPU_INT_FLAGS_DEFAULT;
|
|
|
|
grub_cpu_interrupt (0x13, ®s);
|
|
|
|
for (drive = 0; drive < 2; drive++)
|
|
{
|
|
regs.flags = GRUB_CPU_INT_FLAGS_DEFAULT | GRUB_CPU_INT_FLAGS_CARRY;
|
|
regs.dx = drive;
|
|
|
|
/* call GET DISK TYPE */
|
|
regs.ax = 0x1500;
|
|
grub_cpu_interrupt (0x13, ®s);
|
|
if (regs.flags & GRUB_CPU_INT_FLAGS_CARRY)
|
|
break;
|
|
|
|
/* check if this drive exists */
|
|
if (!(regs.ax & 0x300))
|
|
break;
|
|
}
|
|
|
|
return drive;
|
|
}
|
|
|
|
/*
|
|
* Call IBM/MS INT13 Extensions (int 13 %ah=AH) for DRIVE. DAP
|
|
* is passed for disk address packet. If an error occurs, return
|
|
* non-zero, otherwise zero.
|
|
*/
|
|
|
|
static int
|
|
grub_biosdisk_rw_int13_extensions (int ah, int drive, void *dap)
|
|
{
|
|
struct grub_cpu_int_registers regs;
|
|
regs.ax = ah << 8;
|
|
/* compute the address of disk_address_packet */
|
|
regs.ds = (((grub_addr_t) dap) & 0xffff0000) >> 4;
|
|
regs.si = (((grub_addr_t) dap) & 0xffff);
|
|
regs.dx = drive;
|
|
regs.flags = GRUB_CPU_INT_FLAGS_DEFAULT;
|
|
|
|
grub_cpu_interrupt (0x13, ®s);
|
|
return regs.ax >> 8;
|
|
}
|
|
|
|
static int
|
|
grub_biosdisk_get_drive (const char *name)
|
|
{
|
|
unsigned long drive;
|
|
|
|
if ((name[0] != 'f' && name[0] != 'h') || name[1] != 'd')
|
|
goto fail;
|
|
|
|
drive = grub_strtoul (name + 2, 0, 10);
|
|
if (grub_errno != GRUB_ERR_NONE)
|
|
goto fail;
|
|
|
|
if (name[0] == 'h')
|
|
drive += 0x80;
|
|
|
|
return (int) drive ;
|
|
|
|
fail:
|
|
grub_error (GRUB_ERR_UNKNOWN_DEVICE, "not a biosdisk");
|
|
return -1;
|
|
}
|
|
|
|
static int
|
|
grub_biosdisk_call_hook (int (*hook) (const char *name), int drive)
|
|
{
|
|
char name[10];
|
|
|
|
grub_sprintf (name, (drive & 0x80) ? "hd%d" : "fd%d", drive & (~0x80));
|
|
return hook (name);
|
|
}
|
|
|
|
static int
|
|
grub_biosdisk_iterate (int (*hook) (const char *name))
|
|
{
|
|
int drive;
|
|
int num_floppies;
|
|
|
|
/* For hard disks, attempt to read the MBR. */
|
|
for (drive = 0x80; drive < 0x90; drive++)
|
|
{
|
|
if (grub_biosdisk_rw_standard (0x02, drive, 0, 0, 1, 1,
|
|
GRUB_MEMORY_MACHINE_SCRATCH_SEG) != 0)
|
|
{
|
|
grub_dprintf ("disk", "Read error when probing drive 0x%2x\n", drive);
|
|
break;
|
|
}
|
|
|
|
if (grub_biosdisk_call_hook (hook, drive))
|
|
return 1;
|
|
}
|
|
|
|
if (cd_drive)
|
|
{
|
|
if (grub_biosdisk_call_hook (hook, cd_drive))
|
|
return 1;
|
|
}
|
|
|
|
/* For floppy disks, we can get the number safely. */
|
|
num_floppies = grub_biosdisk_get_num_floppies ();
|
|
for (drive = 0; drive < num_floppies; drive++)
|
|
if (grub_biosdisk_call_hook (hook, drive))
|
|
return 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static grub_err_t
|
|
grub_biosdisk_open (const char *name, grub_disk_t disk)
|
|
{
|
|
grub_uint64_t total_sectors = 0;
|
|
int drive;
|
|
struct grub_biosdisk_data *data;
|
|
|
|
drive = grub_biosdisk_get_drive (name);
|
|
if (drive < 0)
|
|
return grub_errno;
|
|
|
|
disk->has_partitions = ((drive & 0x80) && (drive != cd_drive));
|
|
disk->id = drive;
|
|
|
|
data = (struct grub_biosdisk_data *) grub_zalloc (sizeof (*data));
|
|
if (! data)
|
|
return grub_errno;
|
|
|
|
data->drive = drive;
|
|
|
|
if ((cd_drive) && (drive == cd_drive))
|
|
{
|
|
data->flags = GRUB_BIOSDISK_FLAG_LBA | GRUB_BIOSDISK_FLAG_CDROM;
|
|
data->sectors = 32;
|
|
total_sectors = GRUB_ULONG_MAX; /* TODO: get the correct size. */
|
|
}
|
|
else if (drive & 0x80)
|
|
{
|
|
/* HDD */
|
|
int version;
|
|
|
|
version = grub_biosdisk_check_int13_extensions (drive);
|
|
if (version)
|
|
{
|
|
struct grub_biosdisk_drp *drp
|
|
= (struct grub_biosdisk_drp *) GRUB_MEMORY_MACHINE_SCRATCH_ADDR;
|
|
|
|
/* Clear out the DRP. */
|
|
grub_memset (drp, 0, sizeof (*drp));
|
|
drp->size = sizeof (*drp);
|
|
if (! grub_biosdisk_get_diskinfo_int13_extensions (drive, drp))
|
|
{
|
|
data->flags = GRUB_BIOSDISK_FLAG_LBA;
|
|
|
|
if (drp->total_sectors)
|
|
total_sectors = drp->total_sectors;
|
|
else
|
|
/* Some buggy BIOSes doesn't return the total sectors
|
|
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 (! (data->flags & GRUB_BIOSDISK_FLAG_CDROM))
|
|
{
|
|
if (grub_biosdisk_get_diskinfo_standard (drive,
|
|
&data->cylinders,
|
|
&data->heads,
|
|
&data->sectors) != 0)
|
|
{
|
|
if (total_sectors && (data->flags & GRUB_BIOSDISK_FLAG_LBA))
|
|
{
|
|
data->sectors = 63;
|
|
data->heads = 255;
|
|
data->cylinders
|
|
= grub_divmod64 (total_sectors
|
|
+ data->heads * data->sectors - 1,
|
|
data->heads * data->sectors, 0);
|
|
}
|
|
else
|
|
{
|
|
grub_free (data);
|
|
return grub_error (GRUB_ERR_BAD_DEVICE, "%s cannot get C/H/S values", disk->name);
|
|
}
|
|
}
|
|
|
|
if (! total_sectors)
|
|
total_sectors = data->cylinders * data->heads * data->sectors;
|
|
}
|
|
|
|
disk->total_sectors = total_sectors;
|
|
disk->data = data;
|
|
|
|
return GRUB_ERR_NONE;
|
|
}
|
|
|
|
static void
|
|
grub_biosdisk_close (grub_disk_t disk)
|
|
{
|
|
grub_free (disk->data);
|
|
}
|
|
|
|
/* For readability. */
|
|
#define GRUB_BIOSDISK_READ 0
|
|
#define GRUB_BIOSDISK_WRITE 1
|
|
|
|
#define GRUB_BIOSDISK_CDROM_RETRY_COUNT 3
|
|
|
|
static grub_err_t
|
|
grub_biosdisk_rw (int cmd, grub_disk_t disk,
|
|
grub_disk_addr_t sector, grub_size_t size,
|
|
unsigned segment)
|
|
{
|
|
struct grub_biosdisk_data *data = disk->data;
|
|
|
|
if (data->flags & GRUB_BIOSDISK_FLAG_LBA)
|
|
{
|
|
struct grub_biosdisk_dap *dap;
|
|
|
|
dap = (struct grub_biosdisk_dap *) (GRUB_MEMORY_MACHINE_SCRATCH_ADDR
|
|
+ (data->sectors
|
|
<< GRUB_DISK_SECTOR_BITS));
|
|
dap->length = sizeof (*dap);
|
|
dap->reserved = 0;
|
|
dap->blocks = size;
|
|
dap->buffer = segment << 16; /* The format SEGMENT:ADDRESS. */
|
|
dap->block = sector;
|
|
|
|
if (data->flags & GRUB_BIOSDISK_FLAG_CDROM)
|
|
{
|
|
int i;
|
|
|
|
if (cmd)
|
|
return grub_error (GRUB_ERR_WRITE_ERROR, "can\'t write to cdrom");
|
|
|
|
dap->blocks = (dap->blocks + 3) >> 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;
|
|
|
|
if (i == GRUB_BIOSDISK_CDROM_RETRY_COUNT)
|
|
return grub_error (GRUB_ERR_READ_ERROR, "cdrom read error");
|
|
}
|
|
else
|
|
if (grub_biosdisk_rw_int13_extensions (cmd + 0x42, data->drive, dap))
|
|
{
|
|
/* Fall back to the CHS mode. */
|
|
data->flags &= ~GRUB_BIOSDISK_FLAG_LBA;
|
|
disk->total_sectors = data->cylinders * data->heads * data->sectors;
|
|
return grub_biosdisk_rw (cmd, disk, sector, size, segment);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
unsigned coff, hoff, soff;
|
|
unsigned head;
|
|
|
|
/* It is impossible to reach over 8064 MiB (a bit less than LBA24) with
|
|
the traditional CHS access. */
|
|
if (sector >
|
|
1024 /* cylinders */ *
|
|
256 /* heads */ *
|
|
63 /* spt */)
|
|
return grub_error (GRUB_ERR_OUT_OF_RANGE, "%s out of disk", disk->name);
|
|
|
|
soff = ((grub_uint32_t) sector) % data->sectors + 1;
|
|
head = ((grub_uint32_t) sector) / data->sectors;
|
|
hoff = head % data->heads;
|
|
coff = head / data->heads;
|
|
|
|
if (coff >= data->cylinders)
|
|
return grub_error (GRUB_ERR_OUT_OF_RANGE, "%s out of disk", disk->name);
|
|
|
|
if (grub_biosdisk_rw_standard (cmd + 0x02, data->drive,
|
|
coff, hoff, soff, size, segment))
|
|
{
|
|
switch (cmd)
|
|
{
|
|
case GRUB_BIOSDISK_READ:
|
|
return grub_error (GRUB_ERR_READ_ERROR, "%s read error", disk->name);
|
|
case GRUB_BIOSDISK_WRITE:
|
|
return grub_error (GRUB_ERR_WRITE_ERROR, "%s write error", disk->name);
|
|
}
|
|
}
|
|
}
|
|
|
|
return GRUB_ERR_NONE;
|
|
}
|
|
|
|
/* 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)
|
|
{
|
|
grub_size_t size;
|
|
grub_uint32_t offset;
|
|
|
|
/* OFFSET = SECTOR % SECTORS */
|
|
grub_divmod64 (sector, sectors, &offset);
|
|
|
|
size = sectors - offset;
|
|
|
|
/* Limit the max to 0x7f because of Phoenix EDD. */
|
|
if (size > 0x7f)
|
|
size = 0x7f;
|
|
|
|
return size;
|
|
}
|
|
|
|
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;
|
|
|
|
len = get_safe_sectors (sector, data->sectors);
|
|
if (len > size)
|
|
len = size;
|
|
|
|
if (grub_biosdisk_rw (GRUB_BIOSDISK_READ, disk, sector, len,
|
|
GRUB_MEMORY_MACHINE_SCRATCH_SEG))
|
|
return grub_errno;
|
|
|
|
grub_memcpy (buf, (void *) GRUB_MEMORY_MACHINE_SCRATCH_ADDR,
|
|
len << GRUB_DISK_SECTOR_BITS);
|
|
buf += len << GRUB_DISK_SECTOR_BITS;
|
|
sector += len;
|
|
size -= len;
|
|
}
|
|
|
|
return grub_errno;
|
|
}
|
|
|
|
static grub_err_t
|
|
grub_biosdisk_write (grub_disk_t disk, grub_disk_addr_t sector,
|
|
grub_size_t size, const char *buf)
|
|
{
|
|
struct grub_biosdisk_data *data = disk->data;
|
|
|
|
while (size)
|
|
{
|
|
grub_size_t len;
|
|
|
|
len = get_safe_sectors (sector, data->sectors);
|
|
if (len > size)
|
|
len = size;
|
|
|
|
grub_memcpy ((void *) GRUB_MEMORY_MACHINE_SCRATCH_ADDR, buf,
|
|
len << GRUB_DISK_SECTOR_BITS);
|
|
|
|
if (grub_biosdisk_rw (GRUB_BIOSDISK_WRITE, disk, sector, len,
|
|
GRUB_MEMORY_MACHINE_SCRATCH_SEG))
|
|
return grub_errno;
|
|
|
|
buf += len << GRUB_DISK_SECTOR_BITS;
|
|
sector += len;
|
|
size -= len;
|
|
}
|
|
|
|
return grub_errno;
|
|
}
|
|
|
|
static struct grub_disk_dev grub_biosdisk_dev =
|
|
{
|
|
.name = "biosdisk",
|
|
.id = GRUB_DISK_DEVICE_BIOSDISK_ID,
|
|
.iterate = grub_biosdisk_iterate,
|
|
.open = grub_biosdisk_open,
|
|
.close = grub_biosdisk_close,
|
|
.read = grub_biosdisk_read,
|
|
.write = grub_biosdisk_write,
|
|
.next = 0
|
|
};
|
|
|
|
static void
|
|
grub_disk_biosdisk_fini (void)
|
|
{
|
|
grub_disk_dev_unregister (&grub_biosdisk_dev);
|
|
}
|
|
|
|
GRUB_MOD_INIT(biosdisk)
|
|
{
|
|
struct grub_biosdisk_cdrp *cdrp
|
|
= (struct grub_biosdisk_cdrp *) GRUB_MEMORY_MACHINE_SCRATCH_ADDR;
|
|
|
|
if (grub_disk_firmware_is_tainted)
|
|
{
|
|
grub_printf ("Firmware is marked as tainted, refusing to initialize.\n");
|
|
return;
|
|
}
|
|
grub_disk_firmware_fini = grub_disk_biosdisk_fini;
|
|
|
|
grub_memset (cdrp, 0, sizeof (*cdrp));
|
|
cdrp->size = sizeof (*cdrp);
|
|
cdrp->media_type = 0xFF;
|
|
if ((! grub_biosdisk_get_cdinfo_int13_extensions (grub_boot_drive, cdrp)) &&
|
|
((cdrp->media_type & GRUB_BIOSDISK_CDTYPE_MASK)
|
|
== GRUB_BIOSDISK_CDTYPE_NO_EMUL))
|
|
cd_drive = cdrp->drive_no;
|
|
|
|
grub_disk_dev_register (&grub_biosdisk_dev);
|
|
}
|
|
|
|
GRUB_MOD_FINI(biosdisk)
|
|
{
|
|
grub_disk_biosdisk_fini ();
|
|
}
|