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grub/disk/i386/pc/biosdisk.c

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/*
* PUPA -- Preliminary Universal Programming Architecture for GRUB
* Copyright (C) 1999,2000,2001,2002 Free Software Foundation, Inc.
* Copyright (C) 2002 Yoshinori K. Okuji <okuji@enbug.org>
*
* PUPA 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 2 of the License, or
* (at your option) any later version.
*
* This program 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 PUPA; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <pupa/machine/biosdisk.h>
#include <pupa/machine/memory.h>
#include <pupa/disk.h>
#include <pupa/mm.h>
#include <pupa/types.h>
#include <pupa/misc.h>
#include <pupa/err.h>
#include <pupa/term.h>
/* Drive Parameters. */
struct pupa_biosdisk_drp
{
pupa_uint16_t size;
pupa_uint16_t flags;
pupa_uint32_t cylinders;
pupa_uint32_t heads;
pupa_uint32_t sectors;
pupa_uint64_t total_sectors;
pupa_uint16_t bytes_per_sector;
/* ver 2.0 or higher */
pupa_uint32_t EDD_configuration_parameters;
/* ver 3.0 or higher */
pupa_uint16_t signature_dpi;
pupa_uint8_t length_dpi;
pupa_uint8_t reserved[3];
pupa_uint8_t name_of_host_bus[4];
pupa_uint8_t name_of_interface_type[8];
pupa_uint8_t interface_path[8];
pupa_uint8_t device_path[8];
pupa_uint8_t reserved2;
pupa_uint8_t checksum;
/* XXX: This is necessary, because the BIOS of Thinkpad X20
writes a garbage to the tail of drive parameters,
regardless of a size specified in a caller. */
pupa_uint8_t dummy[16];
} __attribute__ ((packed));
/* Disk Address Packet. */
struct pupa_biosdisk_dap
{
pupa_uint8_t length;
pupa_uint8_t reserved;
pupa_uint16_t blocks;
pupa_uint32_t buffer;
pupa_uint64_t block;
} __attribute__ ((packed));
static int
pupa_biosdisk_get_drive (const char *name)
{
unsigned long drive;
if ((name[0] != 'f' && name[0] != 'h') || name[1] != 'd')
goto fail;
drive = pupa_strtoul (name + 2, 0, 10);
if (pupa_errno != PUPA_ERR_NONE)
goto fail;
if (name[0] == 'h')
drive += 0x80;
return (int) drive ;
fail:
pupa_error (PUPA_ERR_UNKNOWN_DEVICE, "not a biosdisk");
return -1;
}
static int
pupa_biosdisk_call_hook (int (*hook) (const char *name), int drive)
{
char name[4];
pupa_sprintf (name, (drive & 0x80) ? "hd%d" : "fd%d", drive & (~0x80));
return hook (name);
}
static int
pupa_biosdisk_iterate (int (*hook) (const char *name))
{
int drive;
int num_floppies;
/* For floppy disks, we can get the number safely. */
num_floppies = pupa_biosdisk_get_num_floppies ();
for (drive = 0; drive < num_floppies; drive++)
if (pupa_biosdisk_call_hook (hook, drive))
return 1;
/* For hard disks, attempt to read the MBR. */
for (drive = 0x80; drive < 0x88; drive++)
{
if (pupa_biosdisk_rw_standard (0x02, drive, 0, 0, 1, 1,
PUPA_MEMORY_MACHINE_SCRATCH_SEG) != 0)
break;
if (pupa_biosdisk_call_hook (hook, drive))
return 1;
}
return 0;
}
static pupa_err_t
pupa_biosdisk_open (const char *name, pupa_disk_t disk)
{
unsigned long total_sectors = 0;
int drive;
struct pupa_biosdisk_data *data;
drive = pupa_biosdisk_get_drive (name);
if (drive < 0)
return pupa_errno;
disk->has_partitions = (drive & 0x80);
disk->id = drive;
data = (struct pupa_biosdisk_data *) pupa_malloc (sizeof (*data));
if (! data)
return pupa_errno;
data->drive = drive;
data->flags = 0;
if (drive & 0x80)
{
/* HDD */
int version;
version = pupa_biosdisk_check_int13_extensions (drive);
if (version)
{
struct pupa_biosdisk_drp *drp
= (struct pupa_biosdisk_drp *) PUPA_MEMORY_MACHINE_SCRATCH_ADDR;
/* Clear out the DRP. */
pupa_memset (drp, 0, sizeof (*drp));
drp->size = sizeof (*drp);
if (pupa_biosdisk_get_diskinfo_int13_extensions (drive, drp))
{
data->flags = PUPA_BIOSDISK_FLAG_LBA;
/* FIXME: 2TB limit. */
if (drp->total_sectors)
total_sectors = drp->total_sectors & ~0L;
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 (pupa_biosdisk_get_diskinfo_standard (drive,
&data->cylinders,
&data->heads,
&data->sectors) != 0)
{
pupa_free (data);
return pupa_error (PUPA_ERR_BAD_DEVICE, "cannot get C/H/S values");
}
if (! total_sectors)
total_sectors = data->cylinders * data->heads * data->sectors;
disk->total_sectors = total_sectors;
disk->data = data;
return PUPA_ERR_NONE;
}
static void
pupa_biosdisk_close (pupa_disk_t disk)
{
pupa_free (disk->data);
}
/* For readability. */
#define PUPA_BIOSDISK_READ 0
#define PUPA_BIOSDISK_WRITE 1
static pupa_err_t
pupa_biosdisk_rw (int cmd, pupa_disk_t disk,
unsigned long sector, unsigned long size,
unsigned segment)
{
struct pupa_biosdisk_data *data = disk->data;
if (data->flags & PUPA_BIOSDISK_FLAG_LBA)
{
struct pupa_biosdisk_dap *dap;
dap = (struct pupa_biosdisk_dap *) (PUPA_MEMORY_MACHINE_SCRATCH_ADDR
+ (data->sectors
<< PUPA_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 (pupa_biosdisk_rw_int13_extensions (cmd + 0x42, data->drive, dap))
{
/* Fall back to the CHS mode. */
data->flags &= ~PUPA_BIOSDISK_FLAG_LBA;
disk->total_sectors = data->cylinders * data->heads * data->sectors;
return pupa_biosdisk_rw (cmd, disk, sector, size, segment);
}
}
else
{
unsigned coff, hoff, soff;
unsigned head;
soff = sector % data->sectors + 1;
head = sector / data->sectors;
hoff = head % data->heads;
coff = head / data->heads;
if (coff >= data->cylinders)
return pupa_error (PUPA_ERR_OUT_OF_RANGE, "out of disk");
if (pupa_biosdisk_rw_standard (cmd + 0x02, data->drive,
coff, hoff, soff, size, segment))
{
switch (cmd)
{
case PUPA_BIOSDISK_READ:
return pupa_error (PUPA_ERR_READ_ERROR, "biosdisk read error");
case PUPA_BIOSDISK_WRITE:
return pupa_error (PUPA_ERR_WRITE_ERROR, "biosdisk write error");
}
}
}
return PUPA_ERR_NONE;
}
static pupa_err_t
pupa_biosdisk_read (pupa_disk_t disk, unsigned long sector,
unsigned long size, char *buf)
{
struct pupa_biosdisk_data *data = disk->data;
while (size)
{
unsigned long len;
len = data->sectors - (sector % data->sectors);
if (len > size)
len = size;
if (pupa_biosdisk_rw (PUPA_BIOSDISK_READ, disk, sector, len,
PUPA_MEMORY_MACHINE_SCRATCH_SEG))
return pupa_errno;
pupa_memcpy (buf, (void *) PUPA_MEMORY_MACHINE_SCRATCH_ADDR,
len << PUPA_DISK_SECTOR_BITS);
buf += len << PUPA_DISK_SECTOR_BITS;
sector += len;
size -= len;
}
return pupa_errno;
}
static pupa_err_t
pupa_biosdisk_write (pupa_disk_t disk, unsigned long sector,
unsigned long size, const char *buf)
{
struct pupa_biosdisk_data *data = disk->data;
while (size)
{
unsigned long len;
len = data->sectors - (sector % data->sectors);
if (len > size)
len = size;
pupa_memcpy ((void *) PUPA_MEMORY_MACHINE_SCRATCH_ADDR, buf,
len << PUPA_DISK_SECTOR_BITS);
if (pupa_biosdisk_rw (PUPA_BIOSDISK_WRITE, disk, sector, len,
PUPA_MEMORY_MACHINE_SCRATCH_SEG))
return pupa_errno;
buf += len << PUPA_DISK_SECTOR_BITS;
sector += len;
size -= len;
}
return pupa_errno;
}
static struct pupa_disk_dev pupa_biosdisk_dev =
{
.name = "biosdisk",
.iterate = pupa_biosdisk_iterate,
.open = pupa_biosdisk_open,
.close = pupa_biosdisk_close,
.read = pupa_biosdisk_read,
.write = pupa_biosdisk_write,
.next = 0
};
void
pupa_biosdisk_init (void)
{
pupa_disk_dev_register (&pupa_biosdisk_dev);
}
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