/* $NetBSD: linux_sp_wrap_powerpc.S,v 1.2 2001/01/19 12:49:22 manu Exp $ */ /*- * Copyright (c) 2001 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Emmanuel Dreyfus. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the NetBSD * Foundation, Inc. and its contributors. * 4. Neither the name of The NetBSD Foundation nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include /* * See linux_exec_powerpc.c. Since the executable expects its arguments 16 * bytes lower than the place ld.so expects them, and since it was not * possible to just duplicate the argument (ld.so erases the pace where * the executable looks for the arguments), then we try to adjust the * stack pointer after ld.so has done its job, and before the executable * is actually run. * * This code is copied onto the stack before program startup, then * ld.so is fooled in thinking this is the actual program. This code adjust * the stack pointer so that the programm will find its arguments and then * transfer control to the real program. The adjustment is of 16 bytes * * XXX This is really a ugly hack, and it should die. */ #define LINUX_SP_WRAP_OFFSET 0x10 .globl _C_LABEL(linux_sp_wrap_start) .globl _C_LABEL(linux_sp_wrap_end) .globl _C_LABEL(linux_sp_wrap_entry) _C_LABEL(linux_sp_wrap_start): addi 1,1,LINUX_SP_WRAP_OFFSET mflr 12 bl 1f 1: mflr 11 mtlr 12 lwz 12, _C_LABEL(linux_sp_wrap_entry)-1b(11) mtctr 12 bctr _C_LABEL(linux_sp_wrap_entry): .long 0 /* orginal prog entry point. setup by kernel */ _C_LABEL(linux_sp_wrap_end):