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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.
*/
/*
* Bootstrap routine for ld.so. Control arrives here either directly from
* exec() upon invocation of a dynamically linked program specifying ld.so
* as its interpreter.
*
* On entry, the stack appears as:
*
* !_______________________! high addresses
* ! !
* ! Information !
* ! Block !
* ! (size varies) !
* !_______________________!
* ! 0 word !
* !_______________________!
* ! Auxiliary !
* ! vector !
* ! 2 word entries !
* ! !
* !_______________________!
* ! 0 word !
* !_______________________!
* ! Environment !
* ! pointers !
* ! ... !
* ! (one word each) !
* !_______________________!
* ! 0 word !
* !_______________________!
* ! Argument ! low addresses
* ! pointers !
* ! Argc words !
* !_______________________!
* ! !
* ! Argc !
* !_______________________! <- %sp + 64
* ! !
* ! Window save area !
* !_______________________! <- %sp
*/
#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: compatibility start, now an error
! +8: alias start (frame exists)
_rt_boot:
ba,a _elf_start
ba,a _aout_start
ba,a _alias_start
! Start up routines -- the aout_start will have a pointer in %o0 that we'll
! want to save -- the elf can be zeroed.
_elf_start:
clr %o0 ! 0 in %o0 == ELF
_aout_start: ! (falls through)
! Create a stack frame, perform PIC set up. If we're a "normal" start, we have
! to determine a bunch of things from our "environment" and construct an ELF
! boot attribute value vector. Otherwise, it's already been done and we can
! skip it.
save %sp, -SA(MINFRAME + (EB_MAX * 8)), %sp
_alias_start:
1: ! PIC prologue
call 2f
sethi %hi(_GLOBAL_OFFSET_TABLE_ + (. - 1b)), %l7
2:
or %l7, %lo(_GLOBAL_OFFSET_TABLE_ + (. - 1b)), %l7
! If %i0 (was %o0) is non-zero, we're in compatibility and we can
! skip construction of the ELF boot attribute vector.
addcc %i0, %g0, %o0 ! set condition codes
bne 1f ! if non-zero, skip setup
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.
add %sp, SA(MINFRAME), %o0 ! &eb[0] == %sp + frame size
set EB_ARGV, %l0 ! code for this entry
st %l0, [%o0] ! store it
add %fp, 68, %l0 ! argument vector is at %fp+68
st %l0, [%o0 + 4] ! store that
ld [%fp + 64], %l1 ! get argument count
inc %l1 ! account for last element of 0
sll %l1, 2, %l1 ! multiply by 4
add %l0, %l1, %l0 ! and get address of first env ptr
st %l0, [%o0 + 12] ! store it in the vector
set EB_ENVP, %l1 ! code for environment base
st %l1, [%o0 + 8] ! store it
set EB_AUXV, %l1 ! get code for auxiliary vector
st %l1, [%o0 + 16] ! store it
2:
ld [%l0], %l1 ! get an entry
tst %l1 ! are we at a "0" entry in environment?
bne 2b ! no, go back and look again
add %l0, 4, %l0 ! incrementing pointer in delay
st %l0, [%o0 + 20] ! store aux vector pointer
set EB_NULL, %l0 ! set up for the last pointer
st %l0, [%o0 + 24] ! and store it
! Call _setup. Two arguments, the ELF bootstrap vector and our (unrelocated)
! _DYNAMIC address. The _DYNAMIC address is located in entry 0 of the GOT
1:
mov %g0, %g2 ! clear globals
mov %g0, %g3
call _setup ! call it
ld [%l7], %o1 ! 2nd parameter
! On return, give callee the exit function in %g1, and either jump to the
! target program (normal), or if return value of _setup is "0" we have
! to return to the compatibility bootstrap. In either case, clear out
! reserved globals.
ld [%l7 + atexit_fini], %g1! get function address
restore %o0, %g0, %l1 ! release frame
tst %l1 ! compatibility return?
be 1f ! yes,
mov %g0, %g4 ! but clear one last global in delay
jmpl %l1, %g0 ! call main program
nop
1:
retl ! compatibility return
nop
.size _rt_boot, . - _rt_boot
#endif
|
