1/* Special support for trampolines 2 * 3 * Copyright (C) 1996, 1997, 2000 Free Software Foundation, Inc. 4 * Written By Michael Meissner 5 * 6 * This file is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License as published by the 8 * Free Software Foundation; either version 2, or (at your option) any 9 * later version. 10 * 11 * In addition to the permissions in the GNU General Public License, the 12 * Free Software Foundation gives you unlimited permission to link the 13 * compiled version of this file with other programs, and to distribute 14 * those programs without any restriction coming from the use of this 15 * file. (The General Public License restrictions do apply in other 16 * respects; for example, they cover modification of the file, and 17 * distribution when not linked into another program.) 18 * 19 * This file is distributed in the hope that it will be useful, but 20 * WITHOUT ANY WARRANTY; without even the implied warranty of 21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 22 * General Public License for more details. 23 * 24 * You should have received a copy of the GNU General Public License 25 * along with this program; see the file COPYING. If not, write to 26 * the Free Software Foundation, 59 Temple Place - Suite 330, 27 * Boston, MA 02111-1307, USA. 28 * 29 * As a special exception, if you link this library with files 30 * compiled with GCC to produce an executable, this does not cause 31 * the resulting executable to be covered by the GNU General Public License. 32 * This exception does not however invalidate any other reasons why 33 * the executable file might be covered by the GNU General Public License. 34 */ 35 36/* Set up trampolines. */ 37 38 .file "tramp.asm" 39 .section ".text" 40 #include "rs6000/ppc-asm.h" 41 42 .type trampoline_initial,@object 43 .align 2 44trampoline_initial: 45 mflr r0 46 bl 1f 47.Lfunc = .-trampoline_initial 48 .long 0 /* will be replaced with function address */ 49.Lchain = .-trampoline_initial 50 .long 0 /* will be replaced with static chain */ 511: mflr r11 52 mtlr r0 53 lwz r0,0(r11) /* function address */ 54 lwz r11,4(r11) /* static chain */ 55 mtctr r0 56 bctr 57 58trampoline_size = .-trampoline_initial 59 .size trampoline_initial,trampoline_size 60 61 62/* R3 = stack address to store trampoline */ 63/* R4 = length of trampoline area */ 64/* R5 = function address */ 65/* R6 = static chain */ 66 67FUNC_START(__trampoline_setup) 68 mflr r0 /* save return address */ 69 bl .LCF0 /* load up __trampoline_initial into r7 */ 70.LCF0: 71 mflr r11 72 addi r7,r11,trampoline_initial-4-.LCF0 /* trampoline address -4 */ 73 74 li r8,trampoline_size /* verify that the trampoline is big enough */ 75 cmpw cr1,r8,r4 76 srwi r4,r4,2 /* # words to move */ 77 addi r9,r3,-4 /* adjust pointer for lwzu */ 78 mtctr r4 79 blt cr1,.Labort 80 81 mtlr r0 82 83 /* Copy the instructions to the stack */ 84.Lmove: 85 lwzu r10,4(r7) 86 stwu r10,4(r9) 87 bdnz .Lmove 88 89 /* Store correct function and static chain */ 90 stw r5,.Lfunc(r3) 91 stw r6,.Lchain(r3) 92 93 /* Now flush both caches */ 94 mtctr r4 95.Lcache: 96 icbi 0,r3 97 dcbf 0,r3 98 addi r3,r3,4 99 bdnz .Lcache 100 101 /* Finally synchronize things & return */ 102 sync 103 isync 104 blr 105 106.Labort: 107 bl JUMP_TARGET(abort) 108FUNC_END(__trampoline_setup) 109 110