1/*- 2 * Copyright (c) 2015-2018 Ruslan Bukin <br@bsdpad.com> 3 * All rights reserved. 4 * 5 * This software was developed by SRI International and the University of 6 * Cambridge Computer Laboratory under DARPA/AFRL contract FA8750-10-C-0237 7 * ("CTSRD"), as part of the DARPA CRASH research programme. 8 * 9 * This software was developed by the University of Cambridge Computer 10 * Laboratory as part of the CTSRD Project, with support from the UK Higher 11 * Education Innovation Fund (HEIF). 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35#include <machine/asm.h> 36/* 37 * func_ptr_type 38 * _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp) 39 */ 40 41ENTRY(.rtld_start) 42 mv s0, a0 /* Put ps_strings in a callee-saved register */ 43 mv s1, sp /* And the stack pointer */ 44 45 addi sp, sp, -16 /* Make room for obj_main & exit proc */ 46 47 mv a1, sp /* exit_proc */ 48 addi a2, a1, 8 /* obj_main */ 49 jal _rtld /* Call the loader */ 50 mv t0, a0 /* Backup the entry point */ 51 52 ld a2, 0(sp) /* Load cleanup */ 53 ld a1, 8(sp) /* Load obj_main */ 54 mv a0, s0 /* Restore ps_strings */ 55 mv sp, s1 /* Restore the stack pointer */ 56 jr t0 /* Jump to the entry point */ 57END(.rtld_start) 58 59/* 60 * t0 = obj pointer 61 * t1 = reloc offset 62 */ 63ENTRY(_rtld_bind_start) 64 /* Save the arguments and ra */ 65 /* We require 17 dwords, but the stack must be aligned to 16-bytes */ 66 addi sp, sp, -(8 * 18) 67 sd a0, (8 * 0)(sp) 68 sd a1, (8 * 1)(sp) 69 sd a2, (8 * 2)(sp) 70 sd a3, (8 * 3)(sp) 71 sd a4, (8 * 4)(sp) 72 sd a5, (8 * 5)(sp) 73 sd a6, (8 * 6)(sp) 74 sd a7, (8 * 7)(sp) 75 sd ra, (8 * 8)(sp) 76 77#ifdef __riscv_float_abi_double 78 /* Save any floating-point arguments */ 79 fsd fa0, (8 * 9)(sp) 80 fsd fa1, (8 * 10)(sp) 81 fsd fa2, (8 * 11)(sp) 82 fsd fa3, (8 * 12)(sp) 83 fsd fa4, (8 * 13)(sp) 84 fsd fa5, (8 * 14)(sp) 85 fsd fa6, (8 * 15)(sp) 86 fsd fa7, (8 * 16)(sp) 87#endif 88 89 /* Reloc offset is 3x of the .got.plt offset */ 90 slli a1, t1, 1 /* Mult items by 2 */ 91 add a1, a1, t1 /* Plus item */ 92 93 /* Load obj */ 94 mv a0, t0 95 96 /* Call into rtld */ 97 jal _rtld_bind 98 99 /* Backup the address to branch to */ 100 mv t0, a0 101 102 /* Restore the arguments and ra */ 103 ld a0, (8 * 0)(sp) 104 ld a1, (8 * 1)(sp) 105 ld a2, (8 * 2)(sp) 106 ld a3, (8 * 3)(sp) 107 ld a4, (8 * 4)(sp) 108 ld a5, (8 * 5)(sp) 109 ld a6, (8 * 6)(sp) 110 ld a7, (8 * 7)(sp) 111 ld ra, (8 * 8)(sp) 112 113#ifdef __riscv_float_abi_double 114 /* Restore floating-point arguments */ 115 fld fa0, (8 * 9)(sp) 116 fld fa1, (8 * 10)(sp) 117 fld fa2, (8 * 11)(sp) 118 fld fa3, (8 * 12)(sp) 119 fld fa4, (8 * 13)(sp) 120 fld fa5, (8 * 14)(sp) 121 fld fa6, (8 * 15)(sp) 122 fld fa7, (8 * 16)(sp) 123#endif 124 addi sp, sp, (8 * 18) 125 126 /* Call into the correct function */ 127 jr t0 128END(_rtld_bind_start) 129