1 /*- 2 * Copyright (c) 2008-2010 Rui Paulo <rpaulo@FreeBSD.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include <sys/types.h> 31 #include <elf.h> 32 #include <efi.h> 33 #include <bootstrap.h> 34 35 #if defined(__aarch64__) 36 #define ElfW_Rel Elf64_Rela 37 #define ElfW_Dyn Elf64_Dyn 38 #define ELFW_R_TYPE ELF64_R_TYPE 39 #define ELF_RELA 40 #elif defined(__arm__) || defined(__i386__) 41 #define ElfW_Rel Elf32_Rel 42 #define ElfW_Dyn Elf32_Dyn 43 #define ELFW_R_TYPE ELF32_R_TYPE 44 #elif defined(__amd64__) 45 #define ElfW_Rel Elf64_Rel 46 #define ElfW_Dyn Elf64_Dyn 47 #define ELFW_R_TYPE ELF64_R_TYPE 48 #else 49 #error architecture not supported 50 #endif 51 #if defined(__aarch64__) 52 #define RELOC_TYPE_NONE R_AARCH64_NONE 53 #define RELOC_TYPE_RELATIVE R_AARCH64_RELATIVE 54 #elif defined(__amd64__) 55 #define RELOC_TYPE_NONE R_X86_64_NONE 56 #define RELOC_TYPE_RELATIVE R_X86_64_RELATIVE 57 #elif defined(__arm__) 58 #define RELOC_TYPE_NONE R_ARM_NONE 59 #define RELOC_TYPE_RELATIVE R_ARM_RELATIVE 60 #elif defined(__i386__) 61 #define RELOC_TYPE_NONE R_386_NONE 62 #define RELOC_TYPE_RELATIVE R_386_RELATIVE 63 #endif 64 65 /* 66 * A simple relocator for EFI binaries. 67 */ 68 EFI_STATUS 69 _reloc(unsigned long ImageBase, ElfW_Dyn *dynamic, EFI_HANDLE image_handle, 70 EFI_SYSTEM_TABLE *system_table) 71 { 72 unsigned long relsz, relent; 73 unsigned long *newaddr; 74 ElfW_Rel *rel; 75 ElfW_Dyn *dynp; 76 77 /* 78 * Find the relocation address, its size and the relocation entry. 79 */ 80 relsz = 0; 81 relent = 0; 82 for (dynp = dynamic; dynp->d_tag != DT_NULL; dynp++) { 83 switch (dynp->d_tag) { 84 case DT_REL: 85 case DT_RELA: 86 rel = (ElfW_Rel *) ((unsigned long) dynp->d_un.d_ptr + 87 ImageBase); 88 break; 89 case DT_RELSZ: 90 case DT_RELASZ: 91 relsz = dynp->d_un.d_val; 92 break; 93 case DT_RELENT: 94 case DT_RELAENT: 95 relent = dynp->d_un.d_val; 96 break; 97 default: 98 break; 99 } 100 } 101 102 /* 103 * Perform the actual relocation. 104 */ 105 for (; relsz > 0; relsz -= relent) { 106 switch (ELFW_R_TYPE(rel->r_info)) { 107 case RELOC_TYPE_NONE: 108 /* No relocation needs be performed. */ 109 break; 110 111 case RELOC_TYPE_RELATIVE: 112 /* Address relative to the base address. */ 113 newaddr = (unsigned long *)(ImageBase + rel->r_offset); 114 *newaddr += ImageBase; 115 /* Add the addend when the ABI uses them */ 116 #ifdef ELF_RELA 117 *newaddr += rel->r_addend; 118 #endif 119 break; 120 default: 121 /* XXX: do we need other relocations ? */ 122 break; 123 } 124 rel = (ElfW_Rel *) ((caddr_t) rel + relent); 125 } 126 127 return (EFI_SUCCESS); 128 } 129