Beginning with DDI 8, the first non-comment line should be:
$maxchan xThis specifies the maximum supported channel number for a DDI driver of version 8 or greater, and should be set to the number of device nodes needed per instance of a device, minus 1. This value must match the value passed to the drv_attach(D3) function in the
drv_maxchanmember of the drvinfo(D4) structure.
For example, an 8-port serial board usually requires at least 16 nodes, two for each port to indicate modem or non-modem control, so $maxchan would be set to 15.
Drivers that use open redirection (``cloning'') should create one channel for the initial open plus one for each clone channel. See open(D2) for more information about open redirection.
For drivers that use only one channel, set $maxchan 0; channel numbers begin at 0. Use a non-zero value only for drivers that support multiple device files per device instance, such as drivers that support multiple operating modes (such as with or without flow control), or multiple sub-parts (such as slices on a disk).
$maxchan must be specified in the Node file as well as for the drv_attach( ) function because the system must compute the number of channels the driver uses before it can create its special defice node files. The device files must be created before the driver can be opened, and the driver may not be loaded until an open( ) call causes an automatic load, so drv_attach( ) may not be called until after the open( ) occurs.
Following the $maxchan line, if any, must be one or more lines in the following format:
module-name node-name type channel user group permissions level
All fields are positional and must be separated by white space. The first four fields are required; the last four fields are optional. Blank lines and lines beginning with ````#'''' or ````*'''' are considered comments and are ignored.
The node file fields are:
The device must be defined as a block and/or character device (Master file characteristics flag set to b or c). When the device node is created, the Master file bmaj or cmaj field values will be used as the major number for the created node.
Beginning with DDI 8, if the name contains %i, one such node file will be created for each instance of this driver's device, with a unique instance number (in variable-width decimal) substituted for the %i. %i is required for DDI 8 drivers prior to UnixWare 7 Release 7.1.
Drivers using a DDI version prior to version 8 may use multiple major numbers. To do this, you specify a value of the form:
type:offsetwhere type is the type of node (b or c) and offset gives the offset to this particular device within the range of major numbers specified for this device type in the Master file. For example, the value ``c:2'' refers to a character major offset 2, which, given a major device type specification of ``15-18'', would translate to a character major number of 17.
config(D2) in the HDK documentation set.
``Device instance'' in HDK Technical Reference in the HDK documentation set.
Make character device files /dev/tty0s, /dev/tty0h, /dev/tty1s, /dev/tty1h, and so forth for a DDI 8 driver, foo:
$maxchan 1 foo tty%is c 0 foo tty%ih c 1
Make pre-DDI 8 character device iasy using minor device 0:
iasy tty00 c 0
Make pre-DDI 8 /dev/net/nau/clone for character device clone. The minor device number is set to the major device number of device nau:
clone net/nau/clone c nau
For a pre-DDI 8 driver, make /dev/imx586_1 for character device clone. The minor device number is set to the major device number of device imx586 plus 1:
clone imx586_1 c:1 imx586
For a DDI 8 or later driver that supports 8 device instances per board, there must be 8 device files for each board. The following Node file causes these devices to be created:
$maxchan 7 mymodname mydev%i/0 c 0 mymodname mydev%i/1 c 1 mymodname mydev%i/2 c 2 mymodname mydev%i/3 c 3 mymodname mydev%i/4 c 4 mymodname mydev%i/5 c 5 mymodname mydev%i/6 c 6 mymodname mydev%i/7 c 7A user-level process can then open the /dev/mydev<N>/<session_number>file, which calls the driver associated with mymodname. The driver is called with the idata for the selected board and the channel number set to the session number. N is a unique number assigned by the system to each new board; no assumptions should be made about the order in which these numbers will be assigned, but once assigned, they will stay the same at least until a reboot. The system will try to keep board instance numbers the same across reboots as well, but if the hardware and/or hardware configuration changes significantly, the system may not be able to preserve the numbers.
The idata is returned by the CFG_ADD subfunction of the config(D2) entry point routine.