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Writing Device Drivers in Oracle® Solaris 11.4

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Updated: November 2020
 
 

Well Known ioctl Interfaces

Many ioctl(9E) operations are common to a class of device drivers. For example, most disk drivers implement many of the dkio(4I) family of ioctls. Many of these interfaces copy in or copy out data structures from the kernel, and some of these data structures have changed size in the LP64 data model. The following section lists the ioctlsthat now require explicit conversion in 64-bit driver ioctl routines for the dkio, fbio(4I), cdio(4I), and mtio(4I) families of ioctls.

ioctl command
Affected data structure
Reference
DKIOCGAPART
DKIOCSAPART
dk_map
dk_allmap
DKIOGVTOC
DKIOSVTOC
partition
vtoc
FBIOPUTCMAP
FBIOGETCMAP
fbcmap
FBIOPUTCMAPI
FBIOGETCMAPI
fbcmap_i
FBIOCCURSOR
FBIOSCURSOR
fbcursor
CDROMREADMODE1
CDROMREADMODE2
cdrom_read
CDROMCDDA
cdrom_cdda
CDROMCDXA
cdrom_cdxa
CDROMSUBCODE
cdrom_subcode
MTIOCTOP
mtop
MTIOCGET
mtget
MTIOCGETDRIVETYPE
mtdrivetype_request
USCSICMD
uscsi_cmd

Device Sizes

The nblocks property is exported by each slice of a block device driver. This property contains the number of 512-byte blocks that each slice of the device can support. The nblocks property is defined as a signed 32-bit quantity, which limits the maximum size of a slice to 1 Tbyte.

Disk devices that provide more than 1 Tbyte of storage per disk must define the Nblocks property, which should still contain the number of 512 byte blocks that the device can support. However, Nblocks is a signed 64-bit quantity, which removes any practical limit on disk space.

The nblocks property is now deprecated. All disk devices should provide the Nblocks property.