reloc.c revision 206376
1206376Srpaulo/*- 2206376Srpaulo * Copyright (c) 2008-2010 Rui Paulo <rpaulo@FreeBSD.org> 3206376Srpaulo * All rights reserved. 4206376Srpaulo * 5206376Srpaulo * Redistribution and use in source and binary forms, with or without 6206376Srpaulo * modification, are permitted provided that the following conditions 7206376Srpaulo * are met: 8206376Srpaulo * 1. Redistributions of source code must retain the above copyright 9206376Srpaulo * notice, this list of conditions and the following disclaimer. 10206376Srpaulo * 2. Redistributions in binary form must reproduce the above copyright 11206376Srpaulo * notice, this list of conditions and the following disclaimer in the 12206376Srpaulo * documentation and/or other materials provided with the distribution. 13206376Srpaulo * 14206376Srpaulo * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15206376Srpaulo * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16206376Srpaulo * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17206376Srpaulo * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18206376Srpaulo * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19206376Srpaulo * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20206376Srpaulo * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21206376Srpaulo * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22206376Srpaulo * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23206376Srpaulo * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24206376Srpaulo * SUCH DAMAGE. 25206376Srpaulo */ 26206376Srpaulo 27206376Srpaulo#include <sys/cdefs.h> 28206376Srpaulo__FBSDID("$FreeBSD: head/sys/boot/i386/efi/reloc.c 206376 2010-04-07 18:16:05Z rpaulo $"); 29206376Srpaulo 30206376Srpaulo#include <sys/types.h> 31206376Srpaulo#include <sys/elf32.h> 32206376Srpaulo#include <efi.h> 33206376Srpaulo 34206376Srpaulo/* 35206376Srpaulo * XXX: we can't include sys/systm.h. 36206376Srpaulo */ 37206376Srpaulo#ifndef CTASSERT /* Allow lint to override */ 38206376Srpaulo#define CTASSERT(x) _CTASSERT(x, __LINE__) 39206376Srpaulo#define _CTASSERT(x, y) __CTASSERT(x, y) 40206376Srpaulo#define __CTASSERT(x, y) typedef char __assert ## y[(x) ? 1 : -1] 41206376Srpaulo#endif 42206376Srpaulo 43206376Srpaulo 44206376Srpaulo/* 45206376Srpaulo * A simple relocator for IA32 EFI binaries. 46206376Srpaulo */ 47206376SrpauloEFI_STATUS 48206376Srpaulo_reloc(unsigned long ImageBase, Elf32_Dyn *dynamic, EFI_HANDLE image_handle, 49206376Srpaulo EFI_SYSTEM_TABLE *system_table) 50206376Srpaulo{ 51206376Srpaulo unsigned long relsz, relent; 52206376Srpaulo unsigned long *newaddr; 53206376Srpaulo Elf32_Rel *rel; 54206376Srpaulo Elf32_Dyn *dynp; 55206376Srpaulo 56206376Srpaulo /* 57206376Srpaulo * Find the relocation address, its size and the relocation entry. 58206376Srpaulo */ 59206376Srpaulo relsz = 0; 60206376Srpaulo relent = 0; 61206376Srpaulo for (dynp = dynamic; dynp->d_tag != DT_NULL; dynp++) { 62206376Srpaulo switch (dynp->d_tag) { 63206376Srpaulo case DT_REL: 64206376Srpaulo rel = (Elf32_Rel *) ((unsigned long) dynp->d_un.d_ptr + 65206376Srpaulo ImageBase); 66206376Srpaulo break; 67206376Srpaulo case DT_RELSZ: 68206376Srpaulo relsz = dynp->d_un.d_val; 69206376Srpaulo break; 70206376Srpaulo case DT_RELENT: 71206376Srpaulo relent = dynp->d_un.d_val; 72206376Srpaulo break; 73206376Srpaulo default: 74206376Srpaulo break; 75206376Srpaulo } 76206376Srpaulo } 77206376Srpaulo 78206376Srpaulo /* 79206376Srpaulo * Perform the actual relocation. 80206376Srpaulo * XXX: We are reusing code for the amd64 version of this, but 81206376Srpaulo * we must make sure the relocation types are the same. 82206376Srpaulo */ 83206376Srpaulo CTASSERT(R_386_NONE == R_X86_64_NONE); 84206376Srpaulo CTASSERT(R_386_RELATIVE == R_X86_64_RELATIVE); 85206376Srpaulo for (; relsz > 0; relsz -= relent) { 86206376Srpaulo switch (ELF32_R_TYPE(rel->r_info)) { 87206376Srpaulo case R_386_NONE: 88206376Srpaulo /* No relocation needs be performed. */ 89206376Srpaulo break; 90206376Srpaulo case R_386_RELATIVE: 91206376Srpaulo /* Address relative to the base address. */ 92206376Srpaulo newaddr = (unsigned long *)(ImageBase + rel->r_offset); 93206376Srpaulo *newaddr += ImageBase; 94206376Srpaulo break; 95206376Srpaulo default: 96206376Srpaulo /* XXX: do we need other relocations ? */ 97206376Srpaulo return (EFI_LOAD_ERROR); 98206376Srpaulo } 99206376Srpaulo rel = (Elf32_Rel *) ((caddr_t) rel + relent); 100206376Srpaulo } 101206376Srpaulo 102206376Srpaulo return (EFI_SUCCESS); 103206376Srpaulo} 104