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#ifdef __i386__ 36#define ElfW_Rel Elf32_Rel 37#define ElfW_Dyn Elf32_Dyn 38#define ELFW_R_TYPE ELF32_R_TYPE 39#elif __amd64__ 40#define ElfW_Rel Elf64_Rel 41#define ElfW_Dyn Elf64_Dyn 42#define ELFW_R_TYPE ELF64_R_TYPE 43#endif 44 45/* 46 * A simple relocator for IA32/AMD64 EFI binaries. 47 */ 48EFI_STATUS 49_reloc(unsigned long ImageBase, ElfW_Dyn *dynamic, EFI_HANDLE image_handle, 50 EFI_SYSTEM_TABLE *system_table) 51{ 52 unsigned long relsz, relent; 53 unsigned long *newaddr; 54 ElfW_Rel *rel; 55 ElfW_Dyn *dynp; 56 57 /* 58 * Find the relocation address, its size and the relocation entry. 59 */ 60 relsz = 0; 61 relent = 0; 62 for (dynp = dynamic; dynp->d_tag != DT_NULL; dynp++) { 63 switch (dynp->d_tag) { 64 case DT_RELA: 65 case DT_REL: 66 rel = (ElfW_Rel *) ((unsigned long) dynp->d_un.d_ptr + 67 ImageBase); 68 break; 69 case DT_RELSZ: 70 case DT_RELASZ: 71 relsz = dynp->d_un.d_val; 72 break; 73 case DT_RELENT: 74 case DT_RELAENT: 75 relent = dynp->d_un.d_val; 76 break; 77 default: 78 break; 79 } 80 } 81 82 /* 83 * Perform the actual relocation. 84 * XXX: We are reusing code for the amd64 version of this, but 85 * we must make sure the relocation types are the same. 86 */ 87 CTASSERT(R_386_NONE == R_X86_64_NONE); 88 CTASSERT(R_386_RELATIVE == R_X86_64_RELATIVE); 89 for (; relsz > 0; relsz -= relent) { 90 switch (ELFW_R_TYPE(rel->r_info)) { 91 case R_386_NONE: 92 /* No relocation needs be performed. */ 93 break; 94 case R_386_RELATIVE: 95 /* Address relative to the base address. */ 96 newaddr = (unsigned long *)(ImageBase + rel->r_offset); 97 *newaddr += ImageBase; 98 break; 99 default: 100 /* XXX: do we need other relocations ? */ 101 break; 102 } 103 rel = (ElfW_Rel *) ((caddr_t) rel + relent); 104 } 105 106 return (EFI_SUCCESS); 107} 108