geteminor(D3)geteminor(D3)NAMEgeteminor - get external minor device number
SYNOPSIS
#include <sys/types.h>
#include <sys/ddi.h>
minor_t geteminor(dev_t dev);
Arguments
dev External device number.
DESCRIPTIONgeteminor returns the external minor number given a device number, dev.
Return Values
The external minor number.
USAGE
External minor numbers are visible to the user. Internal minor numbers
are only visible in the kernel. Since, on some architectures, a driver
can support more than one external major device that maps to the same
internal major device, the kernel keeps a mapping between external minor
numbers and internal minor numbers to allow drivers to index arrays more
easily. For example, a driver may support two devices, each with five
minor numbers. The user may see each set of minor numbers numbered from
zero to four, but the driver sees them as one set of minor numbers
numbered from zero to nine.
All driver entry points are passed device numbers using external minor
numbers.
Systems that map external major device numbers one-to-one with internal
major numbers also map external minor numbers one-to-one with internal
minor numbers.
Level
Initialization, Base or Interrupt.
Synchronization Constraints
Does not sleep.
Driver-defined basic locks, read/write locks, and sleep locks may be held
across calls to this function.
REFERENCESetoimajor(D3), getemajor(D3), getmajor(D3), getminor(D3), makedevice(D3)
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