fetchi(2) [bsd man page]

FETCHI(2)							System Calls Manual							 FETCHI(2)

NAME

       fetchi - fetch from user instruction space (2BSD)

SYNOPSIS

       fetchi(addr)
       int *addr;

DESCRIPTION

       Fetchi  fetches	the  word at addr from the caller's instruction space.	This system call is required on PDP-11's with separate instruction
       and data spaces because the mfpi instruction reads from D-space if the current and previous modes in the program status word are both user.

RETURN VALUE

       Upon successful completion the contents of the caller's instruction space at addr are returned.	Otherwise, a value of -1 is returned.

ERRORS

       [EINVAL]       The kernel has not been compiled for a processor with separate I/D.

       [EFAULT]       Addr points to an address not in the process's allocated instruction space.

BUGS

       The error indication, -1, is a legitimate function value; errno, (see intro(2)), can be used to disambiguate.

       Fetchi is a kludge and exists only to circumvent an alleged security feature on some DEC PDP-11 processors.

       Fetchi is unique to the PDP-11 and 2BSD; its use is discouraged.

3rd Berkeley Distribution					 January 22, 1987							 FETCHI(2)

PHYS(2) 							System Calls Manual							   PHYS(2)

NAME

       phys - allow a process to access physical addresses (2BSD)

SYNOPSIS

       phys(segreg, size, physaddr)
       unsigned int segreg, size, physaddr;

DESCRIPTION

       The  argument  segreg specifies a process virtual (data-space) address range of 8K bytes starting at virtual address segregx8K bytes.  This
       address range is mapped into physical address physaddrx64 bytes.  Only the first sizex64 bytes of this mapping is addressable.  If size	is
       zero, any previous mapping of this virtual address range is nullified.  For example, the call

	    phys(7, 1, 0177775);

       will  map  virtual  addresses  0160000-0160077  into physical addresses 017777500-017777577.  In particular, virtual address 0160060 is the
       PDP-11 console located at physical address 017777560.

       This call may only be executed by the super-user.

ERRORS

       [EPERM]	      The process's effective user ID is not the super-user.

       [EINVAL]       Segreg is less than 0 or greater than 7.

       [EINVAL]       Size is less than 0 or greater than 128.

SEE ALSO

       PDP-11 segmentation hardware

BUGS

       On systems with ENABLE/34(tm) memory mapping boards, phys cannot be used to map in the I/O page.

       This system call is very dangerous.  It is not considered a permanent part of the system.

       Phys is unique to the PDP-11 and 2BSD; its use is discouraged.

3rd Berkeley Distribution					 January 22, 1987							   PHYS(2)