diff options
Diffstat (limited to 'cpukit/libblock/src/bdpart-read.c')
| -rw-r--r-- | cpukit/libblock/src/bdpart-read.c | 348 |
1 files changed, 348 insertions, 0 deletions
diff --git a/cpukit/libblock/src/bdpart-read.c b/cpukit/libblock/src/bdpart-read.c new file mode 100644 index 0000000000..3560dbd3a3 --- /dev/null +++ b/cpukit/libblock/src/bdpart-read.c @@ -0,0 +1,348 @@ +/** + * @file + * + * @ingroup rtems_bdpart + * + * 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.com/license/LICENSE. + */ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include <rtems.h> +#include <rtems/bdbuf.h> +#include <rtems/bdpart.h> +#include <rtems/endian.h> + +#define RTEMS_BDPART_MBR_PARTITION_TYPE( type) \ + { \ + (type), 0xa2U, 0x2eU, 0x38U, \ + 0x38U, 0xb5U, 0xdeU, 0x11U, \ + 0xbcU, 0x13U, 0x00U, 0x1dU, \ + 0x09U, 0xb0U, 0x5fU, 0xa4U \ + } + +static const uuid_t RTEMS_BDPART_MBR_MASTER_TYPE = + RTEMS_BDPART_MBR_PARTITION_TYPE( RTEMS_BDPART_MBR_EMPTY); + +void rtems_bdpart_to_partition_type( uint8_t mbr_type, uuid_t type) +{ + type [0] = mbr_type; + memcpy( type + 1, RTEMS_BDPART_MBR_MASTER_TYPE + 1, sizeof( uuid_t) - 1); +} + +bool rtems_bdpart_to_mbr_partition_type( + const uuid_t type, + uint8_t *mbr_type +) +{ + *mbr_type = rtems_bdpart_mbr_partition_type( type); + + return memcmp( + type + 1, + RTEMS_BDPART_MBR_MASTER_TYPE + 1, + sizeof( uuid_t) - 1 + ) == 0; +} + +/* + * FIXME: This code should the deviceio interface and not the bdbug interface. + */ +rtems_status_code rtems_bdpart_get_disk_data( + const char *disk_name, + dev_t *disk, + rtems_blkdev_bnum *disk_end +) +{ + rtems_status_code sc = RTEMS_SUCCESSFUL; + int rv = 0; + rtems_blkdev_bnum disk_begin = 0; + rtems_blkdev_bnum block_size = 0; + rtems_disk_device *dd = NULL; + struct stat st; + + /* Get disk handle */ + rv = stat( disk_name, &st); + if (rv != 0) { + return RTEMS_INVALID_NAME; + } + *disk = st.st_rdev; + + /* Get disk begin, end and block size */ + dd = rtems_disk_obtain( *disk); + if (dd == NULL) { + return RTEMS_INVALID_NAME; + } + disk_begin = dd->start; + *disk_end = dd->size; + block_size = dd->block_size; + sc = rtems_disk_release( dd); + if (sc != RTEMS_SUCCESSFUL) { + return sc; + } + + /* Check block size */ + if (block_size < RTEMS_BDPART_BLOCK_SIZE) { + return RTEMS_IO_ERROR; + } + + /* Check that we have do not have a logical disk */ + if (disk_begin != 0) { + return RTEMS_IO_ERROR; + } + + return RTEMS_SUCCESSFUL; +} + +static bool rtems_bdpart_is_valid_record( const uint8_t *data) +{ + return data [RTEMS_BDPART_MBR_OFFSET_SIGNATURE_0] + == RTEMS_BDPART_MBR_SIGNATURE_0 + && data [RTEMS_BDPART_MBR_OFFSET_SIGNATURE_1] + == RTEMS_BDPART_MBR_SIGNATURE_1; +} + +static rtems_blkdev_bnum rtems_bdpart_next_ebr( const uint8_t *data) +{ + rtems_blkdev_bnum begin = + rtems_uint32_from_little_endian( data + RTEMS_BDPART_MBR_OFFSET_BEGIN); + uint8_t type = data [RTEMS_BDPART_MBR_OFFSET_TYPE]; + + if (type == RTEMS_BDPART_MBR_EXTENDED) { + return begin; + } else { + return 0; + } +} + +static rtems_status_code rtems_bdpart_read_mbr_partition( + const uint8_t *data, + rtems_bdpart_partition **p, + const rtems_bdpart_partition *p_end, + rtems_blkdev_bnum *ep_begin +) +{ + rtems_blkdev_bnum begin = + rtems_uint32_from_little_endian( data + RTEMS_BDPART_MBR_OFFSET_BEGIN); + rtems_blkdev_bnum size = + rtems_uint32_from_little_endian( data + RTEMS_BDPART_MBR_OFFSET_SIZE); + rtems_blkdev_bnum end = begin + size; + uint8_t type = data [RTEMS_BDPART_MBR_OFFSET_TYPE]; + + if (type == RTEMS_BDPART_MBR_EMPTY) { + return RTEMS_SUCCESSFUL; + } else if (*p == p_end) { + return RTEMS_TOO_MANY; + } else if (begin >= end) { + return RTEMS_IO_ERROR; + } else if (type == RTEMS_BDPART_MBR_EXTENDED) { + if (ep_begin != NULL) { + *ep_begin = begin; + } + } else { + /* Increment partition index */ + ++(*p); + + /* Clear partition */ + memset( *p, 0, sizeof( rtems_bdpart_partition)); + + /* Set values */ + (*p)->begin = begin; + (*p)->end = end; + rtems_bdpart_to_partition_type( type, (*p)->type); + (*p)->flags = data [RTEMS_BDPART_MBR_OFFSET_FLAGS]; + } + + return RTEMS_SUCCESSFUL; +} + +static rtems_status_code rtems_bdpart_read_record( + dev_t disk, + rtems_blkdev_bnum index, + rtems_bdbuf_buffer **block +) +{ + rtems_status_code sc = RTEMS_SUCCESSFUL; + + /* Release previous block if necessary */ + if (*block != NULL) { + sc = rtems_bdbuf_release( *block); + if (sc != RTEMS_SUCCESSFUL) { + return sc; + } + } + + /* Read the record block */ + sc = rtems_bdbuf_read( disk, index, block); + if (sc != RTEMS_SUCCESSFUL) { + return sc; + } + + /* just in case block did not get filled in */ + if ( *block == NULL ) { + return RTEMS_INVALID_ADDRESS; + } + + /* Check MBR signature */ + if (!rtems_bdpart_is_valid_record( (*block)->buffer)) { + return RTEMS_IO_ERROR; + } + + return RTEMS_SUCCESSFUL; +} + +rtems_status_code rtems_bdpart_read( + const char *disk_name, + rtems_bdpart_format *format, + rtems_bdpart_partition *pt, + size_t *count +) +{ + rtems_status_code sc = RTEMS_SUCCESSFUL; + rtems_status_code esc = RTEMS_SUCCESSFUL; + rtems_bdbuf_buffer *block = NULL; + rtems_bdpart_partition *p = pt - 1; + const rtems_bdpart_partition *p_end = pt + (count != NULL ? *count : 0); + rtems_blkdev_bnum ep_begin = 0; /* Extended partition begin */ + rtems_blkdev_bnum ebr = 0; /* Extended boot record block index */ + rtems_blkdev_bnum disk_end = 0; + dev_t disk = 0; + size_t i = 0; + const uint8_t *data = NULL; + + /* Check parameter */ + if (format == NULL || pt == NULL || count == NULL) { + return RTEMS_INVALID_ADDRESS; + } + + /* Set count to a save value */ + *count = 0; + + /* Get disk data */ + sc = rtems_bdpart_get_disk_data( disk_name, &disk, &disk_end); + if (sc != RTEMS_SUCCESSFUL) { + return sc; + } + + /* Read MBR */ + sc = rtems_bdpart_read_record( disk, 0, &block); + if (sc != RTEMS_SUCCESSFUL) { + esc = sc; + goto cleanup; + } + + /* Read the first partition entry */ + data = block->buffer + RTEMS_BDPART_MBR_OFFSET_TABLE_0; + sc = rtems_bdpart_read_mbr_partition( data, &p, p_end, &ep_begin); + if (sc != RTEMS_SUCCESSFUL) { + esc = sc; + goto cleanup; + } + + /* Determine if we have a MBR or GPT format */ + if (rtems_bdpart_mbr_partition_type( p->type) == RTEMS_BDPART_MBR_GPT) { + esc = RTEMS_NOT_IMPLEMENTED; + goto cleanup; + } + + /* Set format */ + format->type = RTEMS_BDPART_FORMAT_MBR; + format->mbr.disk_id = rtems_uint32_from_little_endian( + block->buffer + RTEMS_BDPART_MBR_OFFSET_DISK_ID + ); + format->mbr.dos_compatibility = true; + + /* Iterate through the rest of the primary partition table */ + for (i = 1; i < 4; ++i) { + data += RTEMS_BDPART_MBR_TABLE_ENTRY_SIZE; + + sc = rtems_bdpart_read_mbr_partition( data, &p, p_end, &ep_begin); + if (sc != RTEMS_SUCCESSFUL) { + esc = sc; + goto cleanup; + } + } + + /* Iterate through the logical partitions within the extended partition */ + ebr = ep_begin; + while (ebr != 0) { + rtems_blkdev_bnum tmp = 0; + + /* Read EBR */ + sc = rtems_bdpart_read_record( disk, ebr, &block); + if (sc != RTEMS_SUCCESSFUL) { + esc = sc; + goto cleanup; + } + + /* Read first partition entry */ + sc = rtems_bdpart_read_mbr_partition( + block->buffer + RTEMS_BDPART_MBR_OFFSET_TABLE_0, + &p, + p_end, + NULL + ); + if (sc != RTEMS_SUCCESSFUL) { + esc = sc; + goto cleanup; + } + + /* Adjust partition begin */ + tmp = p->begin + ebr; + if (tmp > p->begin) { + p->begin = tmp; + } else { + esc = RTEMS_IO_ERROR; + goto cleanup; + } + + /* Adjust partition end */ + tmp = p->end + ebr; + if (tmp > p->end) { + p->end = tmp; + } else { + esc = RTEMS_IO_ERROR; + goto cleanup; + } + + /* Read second partition entry for next EBR block */ + ebr = rtems_bdpart_next_ebr( + block->buffer + RTEMS_BDPART_MBR_OFFSET_TABLE_1 + ); + if (ebr != 0) { + /* Adjust partition EBR block index */ + tmp = ebr + ep_begin; + if (tmp > ebr) { + ebr = tmp; + } else { + esc = RTEMS_IO_ERROR; + goto cleanup; + } + } + } + + /* Return partition count */ + *count = (size_t) (p - pt + 1); + +cleanup: + + if (block != NULL) { + rtems_bdbuf_release( block); + } + + return esc; +} |