1 /* 2 * Copyright (C) 2008 Michael Brown <mbrown (at) 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/nap.h> 22 #include <gpxe/efi/efi.h> 23 24 /** @file 25 * 26 * gPXE CPU sleeping API for EFI 27 * 28 */ 29 30 /** 31 * Sleep until next interrupt 32 * 33 */ 34 static void efix86_cpu_nap ( void ) { 35 /* 36 * I can't find any EFI API that allows us to put the CPU to 37 * sleep. The CpuSleep() function is defined in CpuLib.h, but 38 * isn't part of any exposed protocol so we have no way to 39 * call it. 40 * 41 * The EFI shell doesn't seem to bother sleeping the CPU; it 42 * just sits there idly burning power. 43 * 44 */ 45 __asm__ __volatile__ ( "hlt" ); 46 } 47 48 PROVIDE_NAP ( efix86, cpu_nap, efix86_cpu_nap ); 49
