68        O_NDELAY. See open(2).
  69 
  70 
  71        The nparts argument specifies the number of desired partitions.
  72 
  73 
  74        The vtoc argument is a dk_gpt_t structure that describes an EFI
  75        partition table and contains at least the following members:
  76 
  77          uint_t          efi_version;     /* set to EFI_VERSION_CURRENT */
  78          uint_t          efi_nparts;      /* no. of partitions in efi_parts */
  79          uint_t          efi_lbasize;     /* size of block in bytes */
  80          diskaddr_t      efi_last_lba;    /* last block on the disk */
  81          diskaddr_t      efi_first_u_lba; /* first block after labels */
  82          diskaddr_t      efi_last_u_lba;  /* last block before backup labels */
  83          struct dk_part  efi_parts[];     /* array of partitions */
  84 
  85 
  86    Protective Master Boot Record
  87        When a disk receives an EFI label, a protective MBR (PMBR) is also
  88        written containing a single partiton of type EEh and spanning the
  89        entire disk (up to the limit of what can be represented in an MBR). By
  90        default that partition is placed in slot 0 of the PMBR and not marked
  91        as active. Some BIOS implementations contain bugs that require the
  92        entry to be placed into a different slot or to be made active in order
  93        for the system to boot successfully. The default behaviour is modified
  94        for systems with known firmware bugs, refer to
  95        /usr/share/hwdata/efi.fixes for more information.
  96 
  97 
  98 RETURN VALUES
  99        Upon successful completion, efi_alloc_and_init() returns 0. Otherwise
 100        it returns VT_EIO if an I/O operation to the disk fails.
 101 
 102 
 103        Upon successful completion, efi_alloc_and_read() returns a positive
 104        integer indicating the slice index associated with the open file
 105        descriptor.  Otherwise, it returns a negative integer to indicate one
 106        of the following:
 107 
 108        VT_EIO

 169 ATTRIBUTES
 170        See attributes(5) for descriptions of the following attributes:
 171 
 172 
 173 
 174 
 175        +--------------------+-----------------+
 176        |  ATTRIBUTE TYPE    | ATTRIBUTE VALUE |
 177        +--------------------+-----------------+
 178        |Interface Stability | Committed       |
 179        +--------------------+-----------------+
 180        |MT-Level            | Unsafe          |
 181        +--------------------+-----------------+
 182 
 183 SEE ALSO
 184        fmthard(1M), format(1M), prtvtoc(1M), ioctl(2), open(2), libefi(3LIB),
 185        read_vtoc(3EXT), attributes(5), dkio(7I)
 186 
 187 
 188 
 189                                November 20, 2019      EFI_ALLOC_AND_INIT(3EXT)

  68        O_NDELAY. See open(2).
  69 
  70 
  71        The nparts argument specifies the number of desired partitions.
  72 
  73 
  74        The vtoc argument is a dk_gpt_t structure that describes an EFI
  75        partition table and contains at least the following members:
  76 
  77          uint_t          efi_version;     /* set to EFI_VERSION_CURRENT */
  78          uint_t          efi_nparts;      /* no. of partitions in efi_parts */
  79          uint_t          efi_lbasize;     /* size of block in bytes */
  80          diskaddr_t      efi_last_lba;    /* last block on the disk */
  81          diskaddr_t      efi_first_u_lba; /* first block after labels */
  82          diskaddr_t      efi_last_u_lba;  /* last block before backup labels */
  83          struct dk_part  efi_parts[];     /* array of partitions */
  84 
  85 
  86    Protective Master Boot Record
  87        When a disk receives an EFI label, a protective MBR (PMBR) is also
  88        written containing a single partition of type EEh and spanning the
  89        entire disk (up to the limit of what can be represented in an MBR). By
  90        default that partition is placed in slot 0 of the PMBR and not marked
  91        as active. Some BIOS implementations contain bugs that require the
  92        entry to be placed into a different slot or to be made active in order
  93        for the system to boot successfully. The default behaviour is modified
  94        for systems with known firmware bugs, refer to
  95        /usr/share/hwdata/efi.fixes for more information.
  96 
  97 
  98 RETURN VALUES
  99        Upon successful completion, efi_alloc_and_init() returns 0. Otherwise
 100        it returns VT_EIO if an I/O operation to the disk fails.
 101 
 102 
 103        Upon successful completion, efi_alloc_and_read() returns a positive
 104        integer indicating the slice index associated with the open file
 105        descriptor.  Otherwise, it returns a negative integer to indicate one
 106        of the following:
 107 
 108        VT_EIO

 169 ATTRIBUTES
 170        See attributes(5) for descriptions of the following attributes:
 171 
 172 
 173 
 174 
 175        +--------------------+-----------------+
 176        |  ATTRIBUTE TYPE    | ATTRIBUTE VALUE |
 177        +--------------------+-----------------+
 178        |Interface Stability | Committed       |
 179        +--------------------+-----------------+
 180        |MT-Level            | Unsafe          |
 181        +--------------------+-----------------+
 182 
 183 SEE ALSO
 184        fmthard(1M), format(1M), prtvtoc(1M), ioctl(2), open(2), libefi(3LIB),
 185        read_vtoc(3EXT), attributes(5), dkio(7I)
 186 
 187 
 188 
 189                                  May 16, 2020         EFI_ALLOC_AND_INIT(3EXT)