PARAM(3) BSD Library Functions Manual PARAM(3)
param -- common parameters
MAX(size a, size b);
MIN(size a, size b);
The <sys/param.h> header includes some common definitions and macros specific to NetBSD.
The header is perhaps best characterized as a kernel equivalent of <sys/types.h>. The fol-
lowing list summarizes the provided definitions and macros.
o First and foremost, the header defines the version of NetBSD. This is defined as
#define __NetBSD_Version__ 599004800 /* 5.99.48 */
The general format is ``MMmmrrpp00'', where 'MM' and 'mm' denote the major and
minor version, respectively, 'rr' is provided for compatibility, and 'pp' defines
the patch level.
o Common utility macros such as MAX() and MIN() as well as more specific macros such
as STACK(9), ctod(9), mstohz(9), roundup(9), and setbit(9).
o Numerous miscellaneous definitions such as limits, constants for the kernel
memoryallocators(9), scale factors used by the scheduler, kthread(9) priorities,
and many others.
o Definitions provided for historical and compatibility reasons. Examples range
from definitions such as ``#define BSD'' to old priority levels used in the ker-
bitops(3), cdefs(3), types(3), unistd(3)
A <param.h> header appeared already in the Version 4 AT&T UNIX.
BSD April 10, 2011 BSD