.TH PHYS 2 PDP11.SH NAMEphys \- allow a process to access physical addresses.SH SYNOPSIS.B phys(segreg, size, physadr).SH DESCRIPTIONThe argument.I segregspecifies a process virtual (data-space) addressrange of 8K bytes startingat virtual address.IR segreg \(mu8Kbytes.This address range is mapped intophysical address.IR physadr \(mu64bytes.Only the first.IR size \(mu64bytes of this mapping is addressable.If.I sizeis zero,any previous mapping of thisvirtual address range is nullified.For example,the call.PP	phys(6, 1, 0177775);.PPwill map virtual addresses 0160000-0160077 intophysical addresses 017777500-017777577.In particular,virtual address 0160060 is the PDP-11 consolelocated at physical address 017777560..PPThis call may only be executed by the super-user..SH "SEE ALSO"PDP-11 segmentation hardware.SH DIAGNOSTICSThe function value zero is returned ifthe physical mapping is in effect.The value \-1 is returnedif not super-user,if.I segregis not in the range 0-7,if.I sizeis not in the range 0-127,or ifthe specified.I segregis already used for other thana previous call to.IR phys ..SH BUGSThis system call is obviously very machinedependent and very dangerous.This system call is not considereda permanent part of the system..SH ASSEMBLER(phys = 52.).br.B sys phys; segreg; size; physadr