2015-10-15 10:25:28 +02:00

109 lines
3.8 KiB
ArmAsm

/* $NetBSD: rtld_start.S,v 1.1 2014/08/10 05:47:37 matt Exp $ */
/*-
* Copyright (c) 2014 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Matt Thomas of 3am Software Foundry.
*
* 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.
*
* 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 <machine/asm.h>
RCSID("$NetBSD: rtld_start.S,v 1.1 2014/08/10 05:47:37 matt Exp $")
/*
* void _rtld_start(void (*cleanup)(void), const Obj_Entry *obj,
* struct ps_strings *ps_strings);
*
* X0 = NULL
* X1 = NULL
* X2 = ps_strings
* X30 (LR) = 0
* X29 (FP) = 0
*/
ENTRY_NP(_rtld_start)
mov x24, x2 /* save ps_strings */
#if 1
adrp x1, _PROCEDURE_LINKAGE_TABLE_ /* load _DYNAMIC offset from GOT */
ldr x1, [x1, #:got_lo12:_PROCEDURE_LINKAGE_TABLE_]
#else
adrp x1, :got:_DYNAMIC /* load _DYNAMIC offset from GOT */
ldr x1, [x1, #:got_lo12:_DYNAMIC]
#endif
adrp x0, _DYNAMIC /* get &_DYNAMIC */
add x0, x0, #:lo12:_DYNAMIC
sub x25, x0, x1 /* relocbase = &_DYNAMIC - GOT:_DYNAMIC */
mov x1, x25 /* pass as 2nd argument */
bl _rtld_relocate_nonplt_self
sub sp, sp, #16 /* reserve space for returns */
mov x0, sp /* pointer to reserved space */
mov x1, x25 /* pass relocbase */
bl _rtld
mov x17, x0 /* save entry point */
ldp x0, x1, [sp], #16 /* pop cleanup & obj_main */
mov x2, x24 /* restore ps_strings */
br x17 /* call saved entry point */
END(_rtld_start)
/*
* Upon entry from plt0 entry:
* X17 = &PLTGOT[n]
* X16 = &PLTGOT[2]
*/
ENTRY_NP(_rtld_bind_start)
sub sp, sp, #96 /* reserve stack space */
stp x29, x30, [sp, #80] /* save FP & LR */
add x29, sp, #80 /* get new FP */
str x24, [sp, #64] /* save caller-saved register */
stp x6, x7, [sp, #48] /* save arguments */
stp x4, x5, [sp, #32] /* save arguments */
stp x2, x3, [sp, #16] /* save arguments */
stp x0, x1, [sp, #0] /* save arguments */
sub x16, x16, #16 /* adjust to &PLTGOT[0] */
mov x24, x17 /* preserve across _rtld_bind */
sub x1, x17, x16 /* x1 = &PLTGOT[N] - &PLTGOT[2] */
lsr x1, x1, #3 /* x1 = N - 2 */
ldr x0, [x16, #8] /* get obj ptr from &PLTGOT[1] */
bl _rtld_bind
str x0, [x24] /* save address in PLTGOT[N] */
mov x17, x0 /* save address */
ldp x0, x1, [sp, #0] /* restore arguments */
ldp x2, x3, [sp, #16] /* restore arguments */
ldp x4, x5, [sp, #32] /* restore arguments */
ldp x6, x7, [sp, #48] /* restore arguments */
ldr x24, [sp, #64] /* save caller-saved register */
ldp x29, x30, [sp, #80] /* restore FP & LR */
add sp, sp, #96 /* reclaim stack */
br x17 /* call bound function */
END(_rtld_bind_start)