1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2007 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #pragma ident "%Z%%M% %I% %E% SMI" 28 29 #include <stdlib.h> 30 #include <errno.h> 31 #include <fcntl.h> 32 #include <strings.h> 33 #include <stdio.h> 34 #include <sys/types.h> 35 #include <sys/inttypes.h> 36 #include <sys/elf.h> 37 #include <sys/elf_notes.h> 38 #include <sys/mman.h> 39 #include <sys/stat.h> 40 #include "sys/multiboot.h" 41 42 static char *pname; 43 static char *fname; 44 static char *image; /* pointer to the ELF file in memory */ 45 46 #define ELFSEEK(offset) ((void *)(image + offset)) 47 48 /* 49 * patch the load address / entry address 50 * Find the physical load address of the 1st PT_LOAD segment. 51 * Find the amount that e_entry exceeds that amount. 52 * Now go back and subtract the excess from the p_paddr of the LOAD segment. 53 */ 54 static int 55 patch64(Elf64_Ehdr *eh) 56 { 57 Elf64_Phdr *phdr; 58 caddr_t phdrs = NULL; 59 int ndx, mem; 60 multiboot_header_t *mbh; 61 62 /* 63 * Verify some ELF basics - this must be an executable with program 64 * headers. 65 */ 66 if (eh->e_type != ET_EXEC) { 67 (void) fprintf(stderr, "%s: %s: not ET_EXEC, e_type = 0x%x\n", 68 pname, fname, eh->e_type); 69 return (1); 70 } 71 if ((eh->e_phnum == 0) || (eh->e_phoff == 0)) { 72 (void) fprintf(stderr, "%s: %s: no program headers\n", pname, 73 fname); 74 return (1); 75 } 76 77 /* 78 * Get the program headers. 79 */ 80 if ((phdrs = ELFSEEK(eh->e_phoff)) == NULL) { 81 (void) fprintf(stderr, "%s: %s: failed to get %d program " 82 "hdrs\n", pname, fname, eh->e_phnum); 83 return (1); 84 } 85 86 /* 87 * Look for multiboot header. It must be 32-bit aligned and 88 * completely contained in the 1st 8K of the file. 89 */ 90 for (mem = 0; mem < 8192 - sizeof (multiboot_header_t); mem += 4) { 91 mbh = ELFSEEK(mem); 92 if (mbh->magic == MB_HEADER_MAGIC) 93 break; 94 } 95 96 if (mem >= 8192 - sizeof (multiboot_header_t)) { 97 (void) fprintf(stderr, "%s: %s: Didn't find multiboot header\n", 98 pname, fname); 99 return (1); 100 } 101 102 /* 103 * Find the 1:1 mapped PT_LOAD section 104 */ 105 for (ndx = 0; ndx < eh->e_phnum; ndx++) { 106 /*LINTED [ELF program header alignment]*/ 107 phdr = (Elf64_Phdr *)(phdrs + eh->e_phentsize * ndx); 108 109 /* 110 * Find the low memory 1:1 PT_LOAD section! 111 */ 112 if (phdr->p_type != PT_LOAD) 113 continue; 114 115 if (phdr->p_memsz == 0) 116 continue; 117 118 if (phdr->p_paddr != phdr->p_vaddr) 119 continue; 120 121 /* 122 * Make sure the multiboot header is part of the first PT_LOAD 123 * segment, and that the executables entry point starts at the 124 * same segment. 125 */ 126 if ((mem < phdr->p_offset) || 127 (mem >= (phdr->p_offset + phdr->p_filesz))) { 128 (void) fprintf(stderr, "%s: %s: identity mapped " 129 "PT_LOAD wasn't 1st PT_LOAD\n", pname, fname); 130 return (1); 131 } 132 if (eh->e_entry != phdr->p_paddr) { 133 (void) fprintf(stderr, "%s: %s: entry != paddr\n", 134 pname, fname); 135 return (1); 136 } 137 138 /* 139 * Patch the multiboot header fields to get entire file loaded. 140 * Grub uses the MB header for 64 bit loading. 141 */ 142 mbh->load_addr = phdr->p_paddr - phdr->p_offset; 143 mbh->entry_addr = phdr->p_paddr; 144 mbh->header_addr = mbh->load_addr + mem; 145 #ifdef VERBOSE 146 (void) printf(" %s: ELF64 MB header patched\n", fname); 147 (void) printf("\tload_addr now: 0x%x\n", mbh->load_addr); 148 (void) printf("\tentry_addr now: 0x%x\n", mbh->entry_addr); 149 (void) printf("\theader_addr now: 0x%x\n", mbh->header_addr); 150 #endif 151 return (0); 152 } 153 154 (void) fprintf(stderr, "%s: %s: Didn't find 1:1 mapped PT_LOAD " 155 "section\n", pname, fname); 156 return (1); 157 } 158 159 int 160 main(int argc, char **argv) 161 { 162 int fd; 163 uchar_t *ident; 164 void *hdr = NULL; 165 166 /* 167 * we expect one argument -- the elf file 168 */ 169 if (argc != 2) { 170 (void) fprintf(stderr, "usage: %s <unix-elf-file>\n", argv[0]); 171 return (1); 172 } 173 174 pname = strrchr(argv[0], '/'); 175 if (pname == NULL) 176 pname = argv[0]; 177 else 178 ++pname; 179 180 fname = argv[1]; 181 if ((fd = open(fname, O_RDWR)) < 0) { 182 (void) fprintf(stderr, "%s: open(%s, O_RDWR) failed: %s\n", 183 pname, fname, strerror(errno)); 184 return (1); 185 } 186 187 /* 188 * mmap just the 1st 8K -- since that's where the GRUB 189 * multiboot header must be located. 190 */ 191 image = mmap(NULL, 8192, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); 192 if (image == MAP_FAILED) { 193 (void) fprintf(stderr, "%s: mmap() of %s failed: %s\n", 194 pname, fname, strerror(errno)); 195 return (1); 196 } 197 198 ident = ELFSEEK(0); 199 if (ident[EI_MAG0] != ELFMAG0 || ident[EI_MAG1] != ELFMAG1 || 200 ident[EI_MAG2] != ELFMAG2 || ident[EI_MAG3] != ELFMAG3) { 201 (void) fprintf(stderr, "%s: %s: not an ELF file!\n", pname, 202 fname); 203 return (1); 204 } 205 206 if (ident[EI_CLASS] == ELFCLASS64) { 207 hdr = ELFSEEK(0); 208 return (patch64(hdr)); 209 } 210 if (ident[EI_CLASS] != ELFCLASS32) { 211 (void) fprintf(stderr, "%s: Unknown ELF class 0x%x\n", pname, 212 ident[EI_CLASS]); 213 return (1); 214 } 215 return (0); 216 } 217