.\" Copyright (c) 1980 Regents of the University of California.
.\" All rights reserved. The Berkeley software License Agreement
.\" specifies the terms and conditions for redistribution.
.\" @(#)syscall.2 4.1 (Berkeley) %G%
syscall \- indirect system call
.BR "syscall(number, r0, r1, arg ...)" \ \ (PDP-11)
.BR "syscall(number, arg, ...)" \ \ (VAX-11)
performs the system call whose assembly language
interface has the specified
(on the PDP-11, regardless of whether the entry point really
uses them) and further arguments
The r0 value of the system call is returned.
There is no way to simulate system calls
which return values in register r1.
The system call at the location
Execution resumes after the
On the PDP-11, the main purpose of
store arguments in system calls and execute them
out of line in the data segment.
This preserves the purity of the text segment.
If the instruction at the indirect
location is not a system call,
returns error code EINVAL;