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/* $FreeBSD$ */
/* From: NetBSD: rtld_start.S,v 1.1 1996/12/16 20:38:09 cgd Exp */
/*
* Copyright 1996 Matt Thomas <matt@3am-software.com>
* Copyright 2000 John D. Polstra
* All rights reserved.
*
* 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. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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>
#include <machine/pal.h>
.extern _GLOBAL_OFFSET_TABLE_
LEAF(_rtld_start, 0) /* XXX */
.set noreorder
br pv, $33
$33: LDGP(pv)
/* save away the stack pointer */
lda s0, 0(sp) /* get argc from stack */
lda sp, -16(sp) /* space for arguments */
/* save ps_strings pointer */
mov a3, s1
/* Step 1 -- Figure out the displacement */
br t2, $34 /* get our PC */
$34: ldiq t3, $34 /* get where the linker thought we were */
subq t2, t3, t8 /* calculate the displacement */
/* Step 2 -- Find bounds of global offset table */
lda t5, _GLOBAL_OFFSET_TABLE_
addq t8, t5, t9 /* add the displacement */
lda t4, _DYNAMIC
addq t8, t4, t10 /* add the displacement */
/*
* Step 3 -- Every entry in the global offset table needs to
* modified for the displacement before any code will work.
*/
$35: ldq t1, 0(t9) /* load the value */
addq t8, t1, t1 /* add the displacement */
stq t1, 0(t9) /* save the new value */
lda t9, 8(t9) /* point to next entry */
cmpult t9, t10, t1 /* are we done? */
bne t1, $35 /* no, do more */
/*
* Ya! Things are far enough so we can do some dynamic linking!
*/
lda a0, 0(s0) /* initial sp */
lda a1, -16(s0) /* address for exit proc */
lda a2, -8(s0) /* address for obj_main */
CALL(_rtld) /* v0 = _rtld(sp, &exit_proc, &obj_main); */
ldq a1, -16(s0) /* our atexit function */
ldq a2, -8(s0) /* obj_main entry */
lda sp, 16(sp) /* readjust our stack */
mov s0, a0 /* stack pointer */
mov s1, a3 /* ps_strings pointer */
mov v0, t12
jsr ra, (v0), 0 /* (*_start)(sp, cleanup, obj); */
ldgp gp, 0(ra)
CALL(exit)
halt
END(_rtld_start)
.set noat
.globl _rtld_bind_start
.ent _rtld_bind_start
_rtld_bind_start:
lda sp, -168(sp)
.frame sp, 168, $26
/* Preserve all registers that C normally doesn't. */
stq $26, 0(sp)
stq $0, 8(sp)
stq $1, 16(sp)
stq $2, 24(sp)
stq $3, 32(sp)
stq $4, 40(sp)
stq $5, 48(sp)
stq $6, 56(sp)
stq $7, 64(sp)
stq $8, 72(sp)
stq $16, 80(sp)
stq $17, 88(sp)
stq $18, 96(sp)
stq $19, 104(sp)
stq $20, 112(sp)
stq $21, 120(sp)
stq $22, 128(sp)
stq $23, 136(sp)
stq $24, 144(sp)
stq $25, 152(sp)
stq $29, 160(sp)
.mask 0x27ff01ff, -168
/* Set up our $gp */
br gp, $100
$100: ldgp gp, 0(gp)
.prologue 1
/* Set up the arguments for _rtld_bind. */
subq at_reg, t12, a1 /* calculate reloc offset */
ldq a0, 8(t12) /* object structure */
subq a1, 20, a1 /* = (at - t11 - 20) / 12 * 24 */
addq a1, a1, a1
CALL(_rtld_bind)
/* Move the destination address into position. */
mov $0, $27
/* Restore program registers. */
ldq $26, 0(sp)
ldq $0, 8(sp)
ldq $1, 16(sp)
ldq $2, 24(sp)
ldq $3, 32(sp)
ldq $4, 40(sp)
ldq $5, 48(sp)
ldq $6, 56(sp)
ldq $7, 64(sp)
ldq $8, 72(sp)
ldq $16, 80(sp)
ldq $17, 88(sp)
ldq $18, 96(sp)
ldq $19, 104(sp)
ldq $20, 112(sp)
ldq $21, 120(sp)
ldq $22, 128(sp)
ldq $23, 136(sp)
ldq $24, 144(sp)
ldq $25, 152(sp)
ldq $29, 160(sp)
/* Flush the Icache after having modified the .plt code. */
imb
/* Clean up and turn control to the destination */
lda sp, 168(sp)
jmp $31, ($27)
.end _rtld_bind_start
/*
* int cmp0_and_store_int(volatile int *p, int newval);
*
* If an int holds 0, store newval into it; else do nothing. Returns
* the previous value.
*/
LEAF(cmp0_and_store_int, 2)
1: mov a1, t0
ldl_l v0, 0(a0)
bne v0, 3f
stl_c t0, 0(a0)
beq t0, 2f
mb
RET
2: br 1b
3: RET
END(cmp0_and_store_int)
LEAF(atomic_add_int, 2)
0: ldl_l t0, 0(a0)
addq t0, a1, t0
stl_c t0, 0(a0)
beq t0, 1f
mb
RET
1: br 0b
END(atomic_add_int)
/* Atomically increment an int. */
LEAF(atomic_incr_int, 1)
0: ldl_l t0, 0(a0)
addq t0, 1, t0
stl_c t0, 0(a0)
beq t0, 1f
mb
RET
1: br 0b
END(atomic_incr_int)
/* Atomically decrement an int. */
LEAF(atomic_decr_int, 1)
0: ldl_l t0, 0(a0)
subq t0, 1, t0
stl_c t0, 0(a0)
beq t0, 1f
mb
RET
1: br 0b
END(atomic_decr_int)
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