man pages section 9: DDI and DKI Kernel Functions

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Updated: July 2014



ddi_create_minor_node - Create a minor node for this device


#include <sys/stat.h> 
#include <sys/sunddi.h> 

int ddi_create_minor_node(dev_info_t *dip, char *name, int spec_type,
     minor_t minor_num, char *node_type, int flag);

Interface Level

Solaris DDI specific (Solaris DDI).



A pointer to the device's dev_info structure.


The name of this particular minor device.


S_IFCHR or S_IFBLK for character or block minor devices respectively.


The minor number for this particular minor device.


Any string literal that uniquely identifies the type of node. The following predefined node types are provided with this release:


For serial ports


For on board serial ports


For dial out ports


For on board dial out ports


For hard disks


For hard disks with channel or target numbers


For CDROM drives


For CDROM drives with channel or target numbers


For tape drives


For DLPI style 1 or style 2 network devices


For display devices


For pseudo devices


If the device is a clone device then this flag is set to CLONE_DEV else it is set to 0.


ddi_create_minor_node() provides the necessary information to enable the system to create the /dev and /devices hierarchies. The name is used to create the minor name of the block or character special file under the /devices hierarchy. At-sign (@), slash (/), and space are not allowed. The spec_type specifies whether this is a block or character device. The minor_num is the minor number for the device. The node_type is used to create the names in the /dev hierarchy that refers to the names in the /devices hierarchy. See disks(1M) , ports(1M), tapes(1M) , devlinks(1M). Finally flag determines if this is a clone device or not, and what device class the node belongs to.

Return Values

ddi_create_minor_node() returns:


Was able to allocate memory, create the minor data structure, and place it into the linked list of minor devices for this driver.


Minor node creation failed.


The ddi_create_minor_node() function can be called from user context. It is typically called from attach(9E) or ioctl(9E).


Example 1 Create Data Structure Describing Minor Device with Minor Number of 0

The following example creates a data structure describing a minor device called foo which has a minor number of 0. It is of type DDI_NT_BLOCK (a block device) and it is not a clone device.

ddi_create_minor_node(dip, "foo", S_IFBLK, 0, DDI_NT_BLOCK, 0);

See also

add_drv(1M), devlinks(1M), disks(1M), drvconfig(1M), ports(1M), tapes(1M), attach(9E), ddi_remove_minor_node(9F)

Writing Device Drivers for Oracle Solaris 11.2


If the driver is for a network device (node_type DDI_NT_NET), note that the driver name will undergo the driver name constraints identified in the NOTES section of dlpi (7P). Additionally, the minor name must match the driver name for a DLPI style 2 provider. If the driver is a DLPI style 1 provider, the minor name must also match the driver name with the exception that the ppa is appended to the minor name.

Non-gld(7D)-based DLPI network streams drivers are encouraged to switch to gld (7D). Failing this, a driver that creates DLPI style-2 minor nodes must specify CLONE_DEV for its style-2 ddi_create_minor_node() nodes and use qassociate(9F). A driver that supports both style-1 and style-2 minor nodes should return DDI_FAILURE for DDI_INFO_DEVT2INSTANCE and DDI_INFO_DEVT2DEVINFO getinfo(9E) calls to style-2 minor nodes. (The correct association is already established by qassociate(9F)). A driver that only supports style-2 minor nodes can use ddi_no_info(9F) for its getinfo(9E) implementation. For drivers that do not follow these rules, the results of a modunload(1M) of the driver or a cfgadm(1M) remove of hardware controlled by the driver are undefined.



Drivers must remove references to GLOBAL_DEV, NODEBOUND_DEV, NODESPECIFIC_DEV, and ENUMERATED_DEV to compile under Solaris 10 and later versions.