svrctl(2)

NAME
     svrctl - special server control functions

SYNOPSIS
     #include <sys/svrctl.h>

     int svrctl(u32_t request, void *data);

DESCRIPTION
     Svrctl allows root to control the kernel in various ways,  or  implements
     some very Minix specific system calls that don't deserve their own system
     call number.

     This system call makes it easy to add new ways  of  setting  and  getting
     kernel  parameters,  but at the same time, backwards compatibility is not
     guaranteed.  Read  the  <sys/svrctl.h>  include  file  to  see  what  the
     struct's  mentioned  below  look  like.  Most calls are root-only, unless
     specified otherwise.

     The only way to know how to properly use these  calls  is  to  study  the
     associated  kernel or server code, or the programs that already use these
     calls.

     Current requests are:

     MMSIGNON
          Inform MM that the current process wants to become a server.

     MMSWAPON
          Instruct MM to mount a file or device as swapspace.

     MMSWAPOFF
          Tell MM to stop using swapspace.

     FSSIGNON
          Register a new device with FS.

     SYSSIGNON
          Inform the kernel that the process want to  become  a  server.   The
          processes task number is filled-in in a struct systaskinfo.

     SYSGETENV
          Request the value of one or all boot parameters.   Can  be  used  by
          non-root.

RETURN VALUES
     Svrctl returns 0 upon success and -1 upon failure.



AUTHOR
     Philip Homburg <philip@cs.vu.nl>