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 FILE_LICENCE ( GPL2_OR_LATER );
  20
  21 #include <gpxe/device.h>
  22 #include <gpxe/init.h>
  23
  24 /** @file
  25  *
  26  * Initialisation, startup and shutdown routines
  27  *
  28  */
  29
  30 /** "startup() has been called" flag */
  31 static int started = 0;
  32
  33 /**
  34  * Initialise gPXE
  35  *
  36  * This function performs the one-time-only and irreversible
  37  * initialisation steps, such as initialising the heap.  It must be
  38  * called before (almost) any other function.
  39  *
  40  * There is, by definition, no counterpart to this function on the
  41  * shutdown path.
  42  */
  43 void initialise ( void ) {
  44         struct init_fn *init_fn;
  45
  46         /* Call registered initialisation functions */
  47         for_each_table_entry ( init_fn, INIT_FNS )
  48                 init_fn->initialise ();
  49 }
  50
  51 /**
  52  * Start up gPXE
  53  *
  54  * This function performs the repeatable initialisation steps, such as
  55  * probing devices.  You may call startup() and shutdown() multiple
  56  * times (as is done via the PXE API when PXENV_START_UNDI is used).
  57  */
  58 void startup ( void ) {
  59         struct startup_fn *startup_fn;
  60
  61         if ( started )
  62                 return;
  63
  64         /* Call registered startup functions */
  65         for_each_table_entry ( startup_fn, STARTUP_FNS ) {
  66                 if ( startup_fn->startup )
  67                         startup_fn->startup();
  68         }
  69
  70         started = 1;
  71 }
  72
  73 /**
  74  * Shut down gPXE
  75  *
  76  * @v flags             Shutdown behaviour flags
  77  *
  78  * This function reverses the actions of startup(), and leaves gPXE in
  79  * a state ready to be removed from memory.  You may call startup()
  80  * again after calling shutdown().
  81  *
  82  * Call this function only once, before either exiting main() or
  83  * starting up a non-returnable image.
  84  */
  85 void shutdown ( int flags ) {
  86         struct startup_fn *startup_fn;
  87
  88         if ( ! started )
  89                 return;
  90
  91         /* Call registered shutdown functions (in reverse order) */
  92         for_each_table_entry_reverse ( startup_fn, STARTUP_FNS ) {
  93                 if ( startup_fn->shutdown )
  94                         startup_fn->shutdown ( flags );
  95         }
  96
  97         started = 0;
  98 }