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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 1988 AT&T
* All Rights Reserved
*
* Copyright 2007 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
/*
* Bootstrap routine for ld.so. Control arrives here directly from
* exec() upon invocation of a dynamically linked program specifying ld.so
* as its interpreter.
*
* On entry, the stack appears as:
*
* !_______________________! high addresses
* ! 0 word !
* !_______________________!
* ! !
* ! Information !
* ! Block !
* ! (size varies) !
* !_______________________!
* ! Auxiliary !
* ! vector !
* ! 2 word entries !
* ! !
* !_______________________!
* ! 0 word !
* !_______________________!
* ! Environment !
* ! pointers !
* ! ... !
* ! (one word each) !
* !_______________________!
* ! 0 word !
* !_______________________!
* ! Argument ! low addresses
* ! pointers !
* ! Argc words !
* !_______________________!
* ! !
* ! Argc !
* !_______________________! <- %sp + STACK_BIAS + WINDOWSIZE
* ! !
* ! Window save area !
* !_______________________! <- %sp + STACK_BIAS
*/
#if defined(lint)
extern unsigned long _setup();
extern void atexit_fini();
void
main()
{
(void) _setup();
atexit_fini();
}
#else
#include <sys/asm_linkage.h>
#include <sys/param.h>
#include <link.h>
.file "boot.s"
.seg ".text"
.global _rt_boot, _setup, atexit_fini
.type _rt_boot, #function
.align 4
! Entry vector
! +0: normal start
! +4: normal start
! +8: alias start (frame exists) XX64 what's this for?
_rt_boot:
nop
ba,a _elf_start
ba,a _alias_start
! Start up routines
_elf_start:
! Create a stack frame, perform PIC set up. We have
! to determine a bunch of things from our "environment" and
! construct an Elf64_Boot attribute value vector.
save %sp, -SA(MINFRAME + (EB_MAX * 16)), %sp
_alias_start:
1: ! PIC prologue
call 2f
sethi %hh(_GLOBAL_OFFSET_TABLE_ + (. - 1b)), %g1
2: or %g1, %hm(_GLOBAL_OFFSET_TABLE_ + (. - 1b)), %g1
sllx %g1, 32, %g5
sethi %lm(_GLOBAL_OFFSET_TABLE_ + (. - 1b)), %l7
or %l7, %lo(_GLOBAL_OFFSET_TABLE_ + (. - 1b)), %l7
or %g5, %l7, %l7
add %l7, %o7, %l7 ! finish PIC prologue
! %fp points to the root of our ELF bootstrap vector, use it to construct
! the vector and send it to _setup.
!
! The resulting Elf64_Boot vector looks like this:
!
! Offset Contents
! +0x0 EB_ARGV
! +0x8 argv[]
! +0x10 EB_ENVP
! +0x18 envp[]
! +0x20 EB_AUXV
! +0x28 auxv[]
! +0x30 EB_NULL
add %sp, STACK_BIAS + SA(MINFRAME), %o0
! &eb[0] == %sp + frame size
mov EB_ARGV, %l0 ! code for this entry
stx %l0, [%o0] ! store it
add %fp, WINDOWSIZE + 8 + STACK_BIAS, %l0
! argument vector
stx %l0, [%o0 + 0x8] ! store that
ldx [%fp + WINDOWSIZE + STACK_BIAS], %l1
! get argument count (argc)
inc %l1 ! account for last element of 0
sllx %l1, 3, %l1 ! multiply by 8
add %l0, %l1, %l0 ! and get address of first env ptr
stx %l0, [%o0 + 0x18] ! store it in the vector
mov EB_ENVP, %l1 ! code for environment base
stx %l1, [%o0 + 0x10] ! store it
mov EB_AUXV, %l1 ! get code for auxiliary vector
stx %l1, [%o0 + 0x20] ! store it
3: ldx [%l0], %l1 ! get an entry
brnz,pt %l1, 3b ! if not at end, go back and look again
add %l0, 8, %l0 ! incrementing pointer in delay
stx %l0, [%o0 + 0x28] ! store aux vector pointer
mov EB_NULL, %l0 ! set up for the last pointer
stx %l0, [%o0 + 0x30] ! and store it
mov %g0, %g2 ! clear globals
mov %g0, %g3
! Call _setup. Two arguments, the ELF bootstrap vector and our (unrelocated)
! _DYNAMIC address. The _DYNAMIC address is located in entry 0 of the GOT
call _setup ! call it
ldx [%l7], %o1
! On return, give callee the exit function in %g1, and jump to the
! target program, clearing out the reserved globals as we go.
ldx [%l7 + atexit_fini], %g1! get function address
restore %o0, %g0, %l1 ! release frame
jmpl %l1, %g0 ! call main program
mov %g0, %g4 ! clear one last global in delay
.size _rt_boot, . - _rt_boot
#endif
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