Technical data

dkio(7I) Ioctl Requests SunOS 5.5
ioctl() returns the device’s current VTOC (volume table of contents).
DKIOCSVTOC The argument is a pointer to a vtoc structure (described below). This
ioctl() changes the VTOC associated with the device.
struct partition {
ushort p_tag; /∗ ID tag of partition ∗/
ushort p_flag; /∗ permission flags ∗/
daddr_t p_start; /∗ start sector of partition ∗/
long p_size; /∗ # of blocks in partition ∗/
};
If DKIOCSVTOC is used with a floppy diskette, the p_start field must be the first sector of
a cylinder. Multiply the number of heads by the number of sectors per track to compute
the number of sectors per cylinder.
struct vtoc {
unsigned long v_bootinfo[3]; /∗ info needed ∗/
/∗ by mboot ∗/
/∗ (unsupported) ∗/
unsigned long v_sanity; /∗ to verify vtoc ∗/
/∗ sanity ∗/
unsigned long v_version; /∗ layout version ∗/
char v_volume[LEN_DKL_VVOL]; /∗ volume name ∗/
ushort v_sectorsz; /∗ sector size in ∗/
/∗ bytes ∗/
ushort v_nparts; /∗ number of ∗/
/∗ partitions ∗/
unsigned long v_reserved[10]; /∗ free space ∗/
struct partition v_part[V_NUMPAR]; /∗ partition ∗/
/∗ headers∗/
time_t timestamp[V_NUMPAR]; /∗ partition ∗/
/∗ timestamp ∗/
/∗ (unsupported) ∗/
char v_asciilabel[LEN_DKL_ASCII]; /∗ compatibility ∗/
};
/∗
∗ Partition permission flags
∗/
#define V_UNMNT 0x01 /∗ Unmountable partition ∗/
#define V_RONLY 0x10 /∗ Read only ∗/
/∗
∗ Partition identification tags
∗/
#define V_UNASSIGNED 0x00 /∗ unassigned partition ∗/
#define V_BOOT 0x01 /∗ Boot partition ∗/
#define V_ROOT 0x02 /∗ Root filesystem ∗/
7I-82 modified 3 Mar 1995