diff options
Diffstat (limited to 'cpukit/libblock/src/bdpart-write.c')
| -rw-r--r-- | cpukit/libblock/src/bdpart-write.c | 302 |
1 files changed, 302 insertions, 0 deletions
diff --git a/cpukit/libblock/src/bdpart-write.c b/cpukit/libblock/src/bdpart-write.c new file mode 100644 index 0000000000..92e80a24ec --- /dev/null +++ b/cpukit/libblock/src/bdpart-write.c @@ -0,0 +1,302 @@ +/** + * @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 <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( + dev_t disk, + 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( 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; + } + + /* 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; + dev_t disk = 0; + size_t ppc = 0; /* Primary partition count */ + size_t i = 0; + uint8_t *data = 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, &disk, &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( disk, 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( disk, 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 (block != NULL) { + rtems_bdbuf_sync( block); + } + + return esc; +} |