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Device driver programming
01-14-2012
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devswmgr(8) System Manager's Manual devswmgr(8) NAME
devswmgr - utility to manage the device switch database SYNOPSIS
/sbin/devswmgr [-option [parameter]] OPTIONS
Displays the following information about the device switch database: Whether a device switch database was read from the primary file or from a backup file The number of entries that are in the device switch table Displays the major numbers that have been reserved by all drivers, a named driver, or an instance of a named driver. A driver that requires more than one entry in the device switch table uses a unique instance number to reference each of its device switch table entries. Displays help for the devswmgr command. Releases all the major numbers for a device driver if just the driver name is specified. Releases one major number for a device driver if the NAME and the INSTANCENUM of the driver are speci- fied. DESCRIPTION
The devswmgr command helps you manage the device switch table by displaying information about the devices drivers in the table. You can also use the command to release device switch table entries. Typically, you release the entries for a driver after you have unloaded the driver and do not plan to reload it later. Releasing the entries frees them for use by other device drivers. EXAMPLES
The following example shows that a device switch table was loaded from the primary device and that there are 70 entries in it: % /sbin/devswmgr -display Device switch information device switch database read from primary file device switch table has 70 entries The following example shows the major numbers in the device switch table that have been reserved for the driver named cam_disk: % /sbin/devswmgr -getnum driver=cam_disk Device switch reservation list (*=entry in use) driver name instance major ------------------------------- -------- ----- cam_disk 1 8* FILES
The file that manages the device switch databases The primary device switch database file The backup device switch database file SEE ALSO
Commands: scsimgr(8) devswmgr(8)