get external major device number
Synopsis (Not in current DDI version)
major_t getemajor(dev_t dev);
getemajor returns the external major number
given a device number, dev.
External device number.
The external major number.
External major numbers are visible to the user.
Internal major numbers are only visible in the kernel.
Since, on some architectures,
the range of major numbers may be large and sparsely populated,
the kernel keeps a mapping between external and internal major numbers
to save space.
All driver entry points are passed device numbers
using external major numbers.
Usually, a driver with more than one external major number will
have only one internal major number.
However, some system implementations
map one-to-one between external and internal major numbers.
Here, the internal major number is the same as the external major number
and the driver may have more than one internal major number.
Context and synchronization
1, 2, 3, 4, 5, 5mp, 6, 6mp, 7, 7mp, 7.1, 7.1mp
Differences between versions
is not supported in DDI 8;
drivers can access similar information
through the resmgr key and channel number. See
``Device number'' in HDK Technical Reference.
19 June 2005
© 2005 The SCO Group, Inc. All rights reserved.
OpenServer 6 and UnixWare (SVR5) HDK - June 2005