NAME
param —
common parameters
SYNOPSIS
#include <sys/param.h>
size
MAX(
size a,
size b);
size
MIN(
size a,
size b);
DESCRIPTION
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 following list
summarizes the provided definitions and macros.
- 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.
- 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).
- Numerous miscellaneous definitions such as limits,
constants for the kernel
memoryallocators(9),
scale factors used by the scheduler,
kthread(9) priorities, and
many others.
- Definitions provided for historical and compatibility
reasons. Examples range from definitions such as “#define BSD”
to old priority levels used in the kernel.
SEE ALSO
bitops(3),
cdefs(3),
types(3),
unistd(3)
HISTORY
A
<param.h> header appeared already in
the
Version 4 AT&T UNIX.