/* * 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 either directly from * exec() upon invocation of a dynamically linked program specifying ld.so * as its interpreter, or from the "a.out compatibility ld.so". Entry * vector at "_rt_boot" used to discriminate between the two. * * 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 * * In the case of being invoked from the a.out compatibility ld.so, the stack * has the appearance above but also several frames pushed by the compatibility * routine. An "elf_boot" structure is available in %o1 on entry, which * has been "pre-evaluated" to hold much of the information needed from the * original stack frame -- we pass this directly into the main portion of the * ld.so bootstrap. */ #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 ! +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