/**
* @file
*
* @ingroup rtems_bdpart
*
* @brief Block Device Partition Management
*/
/*
* Copyright (c) 2009, 2010
* embedded brains GmbH
* Obere Lagerstr. 30
* D-82178 Puchheim
* Germany
* <rtems@embedded-brains.de>
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <string.h>
#include <rtems.h>
#include <rtems/bdbuf.h>
#include <rtems/bdpart.h>
#include <rtems/endian.h>
static void rtems_bdpart_write_mbr_partition(
uint8_t *data,
uint32_t begin,
uint32_t size,
uint8_t type,
uint8_t flags
)
{
rtems_uint32_to_little_endian( begin, data + RTEMS_BDPART_MBR_OFFSET_BEGIN);
rtems_uint32_to_little_endian( size, data + RTEMS_BDPART_MBR_OFFSET_SIZE);
data [RTEMS_BDPART_MBR_OFFSET_TYPE] = type;
data [RTEMS_BDPART_MBR_OFFSET_FLAGS] = flags;
}
static rtems_status_code rtems_bdpart_new_record(
rtems_disk_device *dd,
rtems_blkdev_bnum index,
rtems_bdbuf_buffer **block
)
{
rtems_status_code sc = RTEMS_SUCCESSFUL;
/* Synchronize previous block if necessary */
if (*block != NULL) {
sc = rtems_bdbuf_sync( *block);
if (sc != RTEMS_SUCCESSFUL) {
return sc;
}
}
/* Read the new record block (this accounts for disk block sizes > 512) */
sc = rtems_bdbuf_read( dd, index, block);
if (sc != RTEMS_SUCCESSFUL) {
return sc;
}
/* just in case block did not get filled in */
if ( *block == NULL ) {
return RTEMS_INVALID_ADDRESS;
}
/* Clear record */
memset( (*block)->buffer, 0, RTEMS_BDPART_BLOCK_SIZE);
/* Write signature */
(*block)->buffer [RTEMS_BDPART_MBR_OFFSET_SIGNATURE_0] =
RTEMS_BDPART_MBR_SIGNATURE_0;
(*block)->buffer [RTEMS_BDPART_MBR_OFFSET_SIGNATURE_1] =
RTEMS_BDPART_MBR_SIGNATURE_1;
return RTEMS_SUCCESSFUL;
}
rtems_status_code rtems_bdpart_write(
const char *disk_name,
const rtems_bdpart_format *format,
const rtems_bdpart_partition *pt,
size_t count
)
{
rtems_status_code sc = RTEMS_SUCCESSFUL;
rtems_status_code esc = RTEMS_SUCCESSFUL;
bool dos_compatibility = format != NULL
&& format->type == RTEMS_BDPART_FORMAT_MBR
&& format->mbr.dos_compatibility;
rtems_bdbuf_buffer *block = NULL;
rtems_blkdev_bnum disk_end = 0;
rtems_blkdev_bnum record_space =
dos_compatibility ? RTEMS_BDPART_MBR_CYLINDER_SIZE : 1;
size_t ppc = 0; /* Primary partition count */
size_t i = 0;
uint8_t *data = NULL;
int fd = -1;
rtems_disk_device *dd = NULL;
/* Check if we have something to do */
if (count == 0) {
/* Nothing to do */
return RTEMS_SUCCESSFUL;
}
/* Check parameter */
if (format == NULL || pt == NULL) {
return RTEMS_INVALID_ADDRESS;
}
/* Get disk data */
sc = rtems_bdpart_get_disk_data( disk_name, &fd, &dd, &disk_end);
if (sc != RTEMS_SUCCESSFUL) {
return sc;
}
/* Align end of disk on cylinder boundary if necessary */
if (dos_compatibility) {
disk_end -= (disk_end % record_space);
}
/* Check that we have a consistent partition table */
for (i = 0; i < count; ++i) {
const rtems_bdpart_partition *p = pt + i;
/* Check that begin and end are proper within the disk */
if (p->begin >= disk_end || p->end > disk_end) {
esc = RTEMS_INVALID_NUMBER;
goto cleanup;
}
/* Check that begin and end are valid */
if (p->begin >= p->end) {
esc = RTEMS_INVALID_NUMBER;
goto cleanup;
}
/* Check that partitions do not overlap */
if (i > 0 && pt [i - 1].end > p->begin) {
esc = RTEMS_INVALID_NUMBER;
goto cleanup;
}
}
/* Check format */
if (format->type != RTEMS_BDPART_FORMAT_MBR) {
esc = RTEMS_NOT_IMPLEMENTED;
goto cleanup;
}
/*
* Set primary partition count. If we have more than four partitions we need
* an extended partition which will contain the partitions of number four and
* above as logical partitions. If we have four or less partitions we can
* use the primary partition table.
*/
ppc = count <= 4 ? count : 3;
/*
* Check that the first primary partition starts at head one and sector one
* under the virtual one head and 63 sectors geometry if necessary.
*/
if (dos_compatibility && pt [0].begin != RTEMS_BDPART_MBR_CYLINDER_SIZE) {
esc = RTEMS_INVALID_NUMBER;
goto cleanup;
}
/*
* Check that we have enough space for the EBRs. The partitions with number
* four and above are logical partitions if we have more than four partitions
* in total. The logical partitions are contained in the extended partition.
* Each logical partition is described via one EBR preceding the partition.
* The space for the EBR and maybe some space which is needed for DOS
* compatibility resides between the partitions. So there have to be gaps of
* the appropriate size between the partitions.
*/
for (i = ppc; i < count; ++i) {
if ((pt [i].begin - pt [i - 1].end) < record_space) {
esc = RTEMS_INVALID_NUMBER;
goto cleanup;
}
}
/* Check that we can convert the parition descriptions to the MBR format */
for (i = 0; i < count; ++i) {
uint8_t type = 0;
const rtems_bdpart_partition *p = pt + i;
/* Check type */
if (!rtems_bdpart_to_mbr_partition_type( p->type, &type)) {
esc = RTEMS_INVALID_ID;
goto cleanup;
}
/* Check flags */
if (p->flags > 0xffU) {
esc = RTEMS_INVALID_ID;
goto cleanup;
}
/* Check ID */
/* TODO */
}
/* New MBR */
sc = rtems_bdpart_new_record( dd, 0, &block);
if (sc != RTEMS_SUCCESSFUL) {
esc = sc;
goto cleanup;
}
/* Write disk ID */
rtems_uint32_to_little_endian(
format->mbr.disk_id,
block->buffer + RTEMS_BDPART_MBR_OFFSET_DISK_ID
);
/* Write primary partition table */
data = block->buffer + RTEMS_BDPART_MBR_OFFSET_TABLE_0;
for (i = 0; i < ppc; ++i) {
const rtems_bdpart_partition *p = pt + i;
/* Write partition entry */
rtems_bdpart_write_mbr_partition(
data,
p->begin,
p->end - p->begin,
rtems_bdpart_mbr_partition_type( p->type),
(uint8_t) p->flags
);
data += RTEMS_BDPART_MBR_TABLE_ENTRY_SIZE;
}
/* Write extended partition with logical partitions if necessary */
if (ppc != count) {
rtems_blkdev_bnum ebr = 0; /* Extended boot record block index */
/* Begin of extended partition */
rtems_blkdev_bnum ep_begin = pt [ppc].begin - record_space;
/* Write extended partition */
rtems_bdpart_write_mbr_partition(
data,
ep_begin,
disk_end - ep_begin,
RTEMS_BDPART_MBR_EXTENDED,
0
);
/* Write logical partitions */
for (i = ppc; i < count; ++i) {
const rtems_bdpart_partition *p = pt + i;
/* Write second partition entry */
if (i > ppc) {
rtems_blkdev_bnum begin = p->begin - record_space;
rtems_bdpart_write_mbr_partition(
block->buffer + RTEMS_BDPART_MBR_OFFSET_TABLE_1,
begin - ep_begin,
disk_end - begin,
RTEMS_BDPART_MBR_EXTENDED,
0
);
}
/* New EBR */
ebr = p->begin - record_space;
sc = rtems_bdpart_new_record( dd, ebr, &block);
if (sc != RTEMS_SUCCESSFUL) {
esc = sc;
goto cleanup;
}
/* Write first partition entry */
rtems_bdpart_write_mbr_partition(
block->buffer + RTEMS_BDPART_MBR_OFFSET_TABLE_0,
record_space,
p->end - p->begin,
rtems_bdpart_mbr_partition_type( p->type),
(uint8_t) p->flags
);
}
}
cleanup:
if (fd >= 0) {
close( fd);
}
if (block != NULL) {
rtems_bdbuf_sync( block);
}
return esc;
}
