/* $OpenBSD: ldasm.S,v 1.47 2019/05/10 13:29:21 guenther Exp $ */ /* $NetBSD: rtld_start.S,v 1.5 2001/08/14 22:17:48 eeh Exp $ */ /* * Copyright (c) 2001 Jason L. Wright (jason@thought.net) * 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. * * 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. */ /*- * Copyright (c) 2000 Eduardo Horvath. * Copyright (c) 1999 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Christos Zoulas and Paul Kranenburg. * * 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. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the NetBSD * Foundation, Inc. and its contributors. * 4. Neither the name of The NetBSD Foundation nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``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 FOUNDATION OR CONTRIBUTORS * 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 <sys/syscall.h> #include <machine/trap.h> #include <machine/asm.h> #define _LOCORE #include <machine/frame.h> /* * ELF: * On startup the stack should contain 16 extended word register save * area, followed by the arg count, etc. * * _rtld() expects the stack pointer to point to two longwords for argument * return followed by argc, etc. We need to create a pointer to * &argc + 16 and pass that in. The return args will be in those * locations. */ /* Offset of ARGC from bottom of stack */ #define ARGC CC64FSZ /* XXX - DL_DATA_SIZE should be (9*8), but I can't think right now. */ #define DL_DATA_SIZE (16*8) .section .boot.text,"ax",@progbits .align 16 .register %g2,#scratch _ENTRY(_dl_start) sub %g0, %g0, %fp ! clear frame sub %sp, 48 + DL_DATA_SIZE, %sp ! make room for dl_data add %sp, BIAS + ARGC, %l3 add %l3, DL_DATA_SIZE, %o0 mov %o0, %l0 /* * need to figure out where _DYNAMIC is located, newer binutils * does not fill in GOT to read _DYNAMIC before relocation. */ call 0f nop call _DYNAMIC+8 ! not executed (no delay needed) 0: ld [%o7+8], %o2 ! load stub call instruction sll %o2, 2, %o2 ! extract PC offset sra %o2, 0, %o2 ! sign-extend add %o2, %o7, %o2 ! real &_DYNAMIC call _dl_boot_bind ! _dl_boot_bind(sp,dl_data,dynamicp) mov %l3, %o1 mov %l3, %o3 ldx [%l0], %l3 ! argc = *sp sllx %l3, 3, %l3 ! argc *= sizeof(long) addx %l0, 8, %o0 ! argv = [sp + argc] addx %l0, 16, %o1 ! envp = sp + 16 + addx %o1, %l3, %o1 ! + argc addx %o3, (7*8), %l2 ldx [%l2], %o2 ! loff = dl_data[AUX_base]; call _dl_boot ! _dl_boot(argv,envp,loff,dl_data) nop add %sp, 48 + DL_DATA_SIZE, %sp ! restore stack 1: call 2f sethi %hi(_GLOBAL_OFFSET_TABLE_+(.-1b)), %l7 2: or %l7, %lo(_GLOBAL_OFFSET_TABLE_+(.-1b)), %l7 add %l7, %o7, %l7 jmp %o0 ldx [%l7 + _dl_dtors], %g1 ! %g1 = cleanup END(_dl_start) /* * We have two separate entry points to the runtime linker. * I'm implementing this following the SPARC v9 ABI spec. * * _dl_bind_start_0(x, y) is called from .PLT0, and is used for * PLT entries above 32768. * * _dl_bind_start_1(x, y) is called from .PLT1, and is used for * PLT entries below 32768. * * The first two entries of PLT2 contain the xword object pointer. * * These routines are called with two longword arguments, * x and y. To calculate the address of the entry, * _dl_bind_start_1(x, y) does: * * n = x >> 15; * * and _dl_bind_start_0(x, y) does: * * i = x - y + 8 - 32768*32; * n = 32768 + (i/5120)*160 + (i%5120)/24; * * Neither routine needs to issue a save since it's already been * done in the PLT entry. */ .text _ENTRY(_dl_bind_start_0) # (x, y) sethi %hi(32768*32-8), %l1 sub %o0, %o1, %l0 /* x - y */ or %l1, %lo(32768*32-8), %l1 sub %l0, %l1, %l0 /* x - y + 8 - 32768*32 */ sethi %hi(5120), %l1 sdivx %l0, %l1, %l1 /* Calculate i/5120 */ ldx [%o1 + (10*4)], %o0 /* Load object pointer from PLT2 */ sllx %l1, 2, %l2 add %l1, %l2, %l2 sllx %l2, 10, %l2 sub %l0, %l2, %l2 /* And i%5120 */ /* Let the division churn for a bit. */ sdivx %l2, 24, %l4 /* (i%5120)/24 */ /* 160 is (32 * 5) or (32 * (4 + 1)) */ sllx %l1, 2, %l3 /* 4 * (i/5120) */ add %l1, %l3, %l3 /* 5 * (i/5120) */ sllx %l3, 5, %l3 /* 32 * 5 * (i/5120) */ sethi %hi(32768), %l6 add %l3, %l4, %l5 /* %l5 = (i/5120)*160 + (i%5120)/24; */ add %l5, %l6, %l5 call _dl_bind /* Call _dl_bind(obj, offset) */ mov %l5, %o1 jmp %o0 /* return value == function address */ restore /* Dump our stack frame */ END(_dl_bind_start_0) _ENTRY(_dl_bind_start_1) # (x, y) srax %o0, 15, %o2 /* %o0 is the index to our PLT slot */ ldx [%o1 + 8], %o0 /* The object pointer is at [%o1 + 8] */ call _dl_bind /* Call _dl_bind(obj, offset) */ mov %o2, %o1 jmp %o0 /* return value == function address */ restore /* Dump our stack frame */ END(_dl_bind_start_1)
