drv_getparm(9F) Kernel Functions for Drivers drv_getparm(9F)
drv_getparm - retrieve kernel state information
int drv_getparm(unsigned int parm, void *value_p);
Architecture independent level 1 (DDI/DKI).
parm The kernel parameter to be obtained. Possible values are:
"small and bold"ReadLTthe value of lbolt. lbolt is a clock_t that is unconditionally incremented by one at each clock tick. No special
treatment is applied when this value overflows the maximum value of the signed integral type clock_t. When this occurs, its
value will be negative, and its magnitude will be decreasing until it again passes zero. It can therefore not be relied
upon to provide an indication of the amount of time that passes since the last system reboot, nor should it be used to mark
an absolute time in the system. Only the difference between two measurements of lbolt is significant. It is used in this
way inside the system kernel for timing purposes.
PPGRP Read the process group identification number. This number determines which processes should receive a HANGUP or BREAK
signal when detected by a driver.
UPROCP Read the process table token value.
PPID Read process identification number.
PSID Read process session identification number.
TIME Read time in seconds.
UCRED Return a pointer to the caller's credential structure.
value_p A pointer to the data space in which the value of the parameter is to be copied.
Since the release of the Solaris 2.6 operating environment, the drv_getparm() function has been replaced by ddi_get_lbolt(9F),
ddi_get_time(9F), and ddi_get_pid(9F).
drv_getparm() function verifies that parm corresponds to a kernel parameter that may be read. If the value of parm does not correspond
to a parameter or corresponds to a parameter that may not be read, -1 is returned. Otherwise, the value of the parameter is stored in the
data space pointed to by value_p.
drv_getparm() does not explicitly check to see whether the device has the appropriate context when the function is called and the function
does not check for correct alignment in the data space pointed to by value_p. It is the responsibility of the driver writer to use this
function only when it is appropriate to do so and to correctly declare the data space needed by the driver.
drv_getparm() returns 0 to indicate success, -1 to indicate failure. The value stored in the space pointed to by value_p is the value of
the parameter if 0 is returned, or undefined if -1 is returned. -1 is returned if you specify a value other than LBOLT, PPGRP, PPID,
PSID, TIME, UCRED, or UPROCP. Always check the return code when using this function.
drv_getparm() can be called from user context only when using PPGRP, PPID, PSID, UCRED, or UPROCP. It can be called from user or interrupt
context when using the LBOLT or TIME argument.
ddi_get_lbolt(9F), ddi_get_pid(9F), ddi_get_time(9F), buf(9S)
Writing Device Drivers
SunOS 5.10 24 Jun 1997 drv_getparm(9F)