1/* $NetBSD: rtld_start.S,v 1.15 2002/10/05 11:59:06 mycroft Exp $ */ 2 3/* 4 * Copyright 1996 Matt Thomas <matt@3am-software.com> 5 * Portions copyright 2002 Charles M. Hannum <root@ihack.net> 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. The name of the author may not be used to endorse or promote products 17 * derived from this software without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31#include <machine/asm.h> 32 33 .data 34.L1: .long _DYNAMIC 35 36/* R9 contains the address of PS_STRINGS and since its caller saved, 37 * we can just use it. R6 has a backup copy of the stack pointer which 38 * we can use as well. Since the VAX has perfectly PIC code, we don't 39 * need to relocate anything upon startup. 40 */ 41ENTRY(_rtld_start, 0) 42 /* Allocate space on the stack for the cleanup and obj_main 43 * entries that _rtld() will provide for us. 44 */ 45 clrl %fp 46 subl2 $8,%sp 47 48 movab _DYNAMIC,%r0 49 subl3 .L1,%r0,%r10 50 pushl %r10 /* relocbase */ 51 pushl %r0 /* &_DYNAMIC */ 52 calls $2,_rtld_relocate_nonplt_self 53 54 pushl %r10 /* relocbase */ 55 pushal 4(%sp) /* sp */ 56 calls $2,_rtld /* entry = _rtld(sp, relocbase) */ 57 58 movq (%sp)+,%r7 /* grab cleanup and obj_main into %r7/%r8 */ 59 jmp 2(%r0) /* jump to entry point + 2 */ 60 61/* 62 * Lazy binding entry point, called via PLT. 63 * 64 * Note: Some functions rely on there not being an additional call frame; 65 * hence the `optimization' to avoid the callg opportunistically. 66 */ 67ALTENTRY(_rtld_bind_start) 68 pushr $0x3f /* save R0-R5 */ 69 movq 24(%sp),%r0 /* get addresses of plt.got & reloc index */ 70 pushl (%r1) /* push relocation index */ 71 pushl %r0 /* push address of obj entry */ 72 calls $2,_rtld_bind 73 movl %r0,28(%sp) /* save return address onto stack */ 74 bicw3 6(%fp),(%r0),%r0/* does the entry mask save any additional regs */ 75 popr $0x3f /* restore R0-R5 (cond flags not modified) */ 76 bneq 4f /* yes? do it the hard way */ 77 addl2 $4,%sp /* no? skip past plt.got on stack */ 78 addl2 $2,(%sp) /* skip past the mask */ 79 rsb /* and jump to it */ 804: addl2 $4,%sp 81 callg (%ap),*(%sp)+ /* return value from _rtld_bind() == actual */ 82 ret 83