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/*  Special support for trampolines
 *
 *   Copyright (C) 1996, 1997, 2000 Free Software Foundation, Inc.
 *   Written By Michael Meissner
 * 
 * This file is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2, or (at your option) any
 * later version.
 * 
 * In addition to the permissions in the GNU General Public License, the
 * Free Software Foundation gives you unlimited permission to link the
 * compiled version of this file with other programs, and to distribute
 * those programs without any restriction coming from the use of this
 * file.  (The General Public License restrictions do apply in other
 * respects; for example, they cover modification of the file, and
 * distribution when not linked into another program.)
 * 
 * This file is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; see the file COPYING.  If not, write to
 * the Free Software Foundation, 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 * 
 *    As a special exception, if you link this library with files
 *    compiled with GCC to produce an executable, this does not cause
 *    the resulting executable to be covered by the GNU General Public License.
 *    This exception does not however invalidate any other reasons why
 *    the executable file might be covered by the GNU General Public License.
 */ 

/* Set up trampolines.  */

        .file   "tramp.asm"
        .section ".text"
        #include "ppc-asm.h"

#ifndef __powerpc64__
        .type   trampoline_initial,@object
        .align  2
trampoline_initial:
        mflr    r0
        bcl     20,31,1f
.Lfunc = .-trampoline_initial
        .long   0                        /* will be replaced with function address */
.Lchain = .-trampoline_initial
        .long   0                        /* will be replaced with static chain */
1:      mflr    r11
        mtlr    r0
        lwz     r0,0(r11)               /* function address */
        lwz     r11,4(r11)              /* static chain */
        mtctr   r0
        bctr

trampoline_size = .-trampoline_initial
        .size   trampoline_initial,trampoline_size


/* R3 = stack address to store trampoline */
/* R4 = length of trampoline area */
/* R5 = function address */
/* R6 = static chain */

FUNC_START(__trampoline_setup)
        mflr    r0              /* save return address */
        bcl     20,31,.LCF0     /* load up __trampoline_initial into r7 */
.LCF0:
        mflr    r11
        addi    r7,r11,trampoline_initial-4-.LCF0 /* trampoline address -4 */

        li      r8,trampoline_size      /* verify that the trampoline is big enough */
        cmpw    cr1,r8,r4
        srwi    r4,r4,2         /* # words to move */
        addi    r9,r3,-4        /* adjust pointer for lwzu */
        mtctr   r4
        blt     cr1,.Labort

        mtlr    r0

        /* Copy the instructions to the stack */
.Lmove:
        lwzu    r10,4(r7)
        stwu    r10,4(r9)
        bdnz    .Lmove

        /* Store correct function and static chain */
        stw     r5,.Lfunc(r3)
        stw     r6,.Lchain(r3)

        /* Now flush both caches */
        mtctr   r4
.Lcache:
        icbi    0,r3
        dcbf    0,r3
        addi    r3,r3,4
        bdnz    .Lcache

        /* Finally synchronize things & return */
        sync
        isync
        blr

.Labort:
#if defined SHARED && defined HAVE_AS_REL16
        bcl     20,31,1f
1:      mflr    r30
        addis   r30,r30,_GLOBAL_OFFSET_TABLE_-1b@ha
        addi    r30,r30,_GLOBAL_OFFSET_TABLE_-1b@l
#endif
        bl      JUMP_TARGET(abort)
FUNC_END(__trampoline_setup)

#endif