src/core/init.c

   1 /*
   2  * Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License as
   6  * published by the Free Software Foundation; either version 2 of the
   7  * License, or any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17  */
  18
  19 #include <gpxe/device.h>
  20 #include <gpxe/init.h>
  21
  22 /** @file
  23  *
  24  * Initialisation, startup and shutdown routines
  25  *
  26  */
  27
  28 /** Registered initialisation functions */
  29 static struct init_fn init_fns[0]
  30         __table_start ( struct init_fn, init_fns );
  31 static struct init_fn init_fns_end[0]
  32         __table_end ( struct init_fn, init_fns );
  33
  34 /** Registered startup/shutdown functions */
  35 static struct startup_fn startup_fns[0]
  36         __table_start ( struct startup_fn, startup_fns );
  37 static struct startup_fn startup_fns_end[0]
  38         __table_end ( struct startup_fn, startup_fns );
  39
  40 /** "startup() has been called" flag */
  41 static int started = 0;
  42
  43 /**
  44  * Initialise gPXE
  45  *
  46  * This function performs the one-time-only and irreversible
  47  * initialisation steps, such as initialising the heap.  It must be
  48  * called before (almost) any other function.
  49  *
  50  * There is, by definition, no counterpart to this function on the
  51  * shutdown path.
  52  */
  53 void initialise ( void ) {
  54         struct init_fn *init_fn;
  55
  56         /* Call registered initialisation functions */
  57         for ( init_fn = init_fns ; init_fn < init_fns_end ; init_fn++ ) {
  58                 init_fn->initialise ();
  59         }
  60 }
  61
  62 /**
  63  * Start up gPXE
  64  *
  65  * This function performs the repeatable initialisation steps, such as
  66  * probing devices.  You may call startup() and shutdown() multiple
  67  * times (as is done via the PXE API when PXENV_START_UNDI is used).
  68  */
  69 void startup ( void ) {
  70         struct startup_fn *startup_fn;
  71
  72         if ( started )
  73                 return;
  74
  75         /* Call registered startup functions */
  76         for ( startup_fn = startup_fns ; startup_fn < startup_fns_end ;
  77               startup_fn++ ) {
  78                 if ( startup_fn->startup )
  79                         startup_fn->startup();
  80         }
  81
  82         started = 1;
  83 }
  84
  85 /**
  86  * Shut down gPXE
  87  *
  88  * @v flags             Shutdown behaviour flags
  89  *
  90  * This function reverses the actions of startup(), and leaves gPXE in
  91  * a state ready to be removed from memory.  You may call startup()
  92  * again after calling shutdown().
  93
  94  * Call this function only once, before either exiting main() or
  95  * starting up a non-returnable image.
  96  */
  97 void shutdown ( int flags ) {
  98         struct startup_fn *startup_fn;
  99
 100         if ( ! started )
 101                 return;
 102
 103         /* Call registered shutdown functions (in reverse order) */
 104         for ( startup_fn = startup_fns_end - 1 ; startup_fn >= startup_fns ;
 105               startup_fn-- ) {
 106                 if ( startup_fn->shutdown )
 107                         startup_fn->shutdown ( flags );
 108         }
 109
 110         started = 0;
 111 }