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 #include <stdlib.h> 28 #include <errno.h> 29 #include <fcntl.h> 30 #include <strings.h> 31 #include <stdio.h> 32 #include <sys/types.h> 33 #include <sys/inttypes.h> 34 #include <sys/elf.h> 35 #include <sys/elf_notes.h> 36 #include <sys/mman.h> 37 #include <sys/stat.h> 38 #include <sys/sysmacros.h> 39 #include "sys/multiboot.h" 40 #include "sys/multiboot2.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 * Find MB2 header tags for entry and patch it. 50 * The first tag is right after header. 51 */ 52 static int 53 patch64_mb2(multiboot2_header_t *mbh2, int file_offset, 54 Elf64_Addr ptload_start, Elf32_Off ptload_offset) 55 { 56 multiboot_header_tag_t *tagp = mbh2->mb2_tags; 57 multiboot_header_tag_address_t *mbaddr = NULL; 58 multiboot_header_tag_entry_address_t *mbentry = NULL; 59 60 /* 61 * Loop until we get end TAG or we have both tags. 62 */ 63 while (tagp->mbh_type != MULTIBOOT_HEADER_TAG_END && 64 (mbaddr == NULL || mbentry == NULL)) { 65 switch (tagp->mbh_type) { 66 case MULTIBOOT_HEADER_TAG_ADDRESS: 67 mbaddr = (multiboot_header_tag_address_t *)tagp; 68 break; 69 case MULTIBOOT_HEADER_TAG_ENTRY_ADDRESS: 70 mbentry = (multiboot_header_tag_entry_address_t *)tagp; 71 break; 72 } 73 tagp = (multiboot_header_tag_t *) 74 ((uintptr_t)tagp + 75 P2ROUNDUP(tagp->mbh_size, MULTIBOOT_TAG_ALIGN)); 76 } 77 78 if (mbaddr == NULL || mbentry == NULL) { 79 (void) fprintf(stderr, "Missing multiboot2 %s tag\n", 80 (mbaddr == NULL)? "address" : "entry"); 81 return (1); 82 } 83 84 /* Patch it. */ 85 mbaddr->mbh_load_addr = ptload_start - ptload_offset; 86 mbaddr->mbh_header_addr = mbaddr->mbh_load_addr + file_offset; 87 mbentry->mbh_entry_addr = ptload_start; 88 89 #ifdef VERBOSE 90 (void) printf(" ELF64 MB2 header patched\n"); 91 (void) printf("\tload_addr now: 0x%x\n", mbaddr->mbh_load_addr); 92 (void) printf("\theader_addr now: 0x%x\n", mbaddr->mbh_header_addr); 93 (void) printf("\tentry_addr now: 0x%x\n", mbentry->mbh_entry_addr); 94 #endif 95 return (0); 96 } 97 98 /* 99 * Patch the load address / entry address for MB1 and MB2 if present. 100 * Find the physical load address of the 1st PT_LOAD segment. 101 * Find the amount that e_entry exceeds that amount. 102 * Now go back and subtract the excess from the p_paddr of the LOAD segment. 103 */ 104 static int 105 patch64(Elf64_Ehdr *eh) 106 { 107 Elf64_Phdr *phdr; 108 caddr_t phdrs = NULL; 109 unsigned ndx, mem, mem2; 110 multiboot_header_t *mbh; 111 multiboot2_header_t *mbh2; 112 113 /* 114 * Verify some ELF basics - this must be an executable with program 115 * headers. 116 */ 117 if (eh->e_type != ET_EXEC) { 118 (void) fprintf(stderr, "%s: %s: not ET_EXEC, e_type = 0x%x\n", 119 pname, fname, eh->e_type); 120 return (1); 121 } 122 if ((eh->e_phnum == 0) || (eh->e_phoff == 0)) { 123 (void) fprintf(stderr, "%s: %s: no program headers\n", pname, 124 fname); 125 return (1); 126 } 127 128 /* 129 * Get the program headers. 130 */ 131 if ((phdrs = ELFSEEK(eh->e_phoff)) == NULL) { 132 (void) fprintf(stderr, "%s: %s: failed to get %d program " 133 "hdrs\n", pname, fname, eh->e_phnum); 134 return (1); 135 } 136 137 /* 138 * Look for multiboot1 header. It must be 32-bit aligned and 139 * completely contained in the 1st 8K of the file. 140 */ 141 for (mem = 0; mem < 8192 - sizeof (multiboot_header_t); mem += 4) { 142 mbh = ELFSEEK(mem); 143 if (mbh->magic == MB_HEADER_MAGIC) 144 break; 145 } 146 147 if (mem >= 8192 - sizeof (multiboot_header_t)) { 148 (void) fprintf(stderr, "%s: %s: Didn't find multiboot header\n", 149 pname, fname); 150 return (1); 151 } 152 153 /* 154 * Look for multiboot2 header. It must be 64-bit aligned and 155 * completely contained in the 1st 32K of the file. 156 * We do not require it to be present. 157 */ 158 ndx = 0; 159 for (mem2 = 0; 160 mem2 <= MULTIBOOT_SEARCH - sizeof (multiboot2_header_t); 161 mem2 += MULTIBOOT_HEADER_ALIGN) { 162 mbh2 = ELFSEEK(mem2); 163 ndx = mbh2->mb2_header_length; 164 if (mbh2->mb2_magic == MULTIBOOT2_HEADER_MAGIC) 165 break; 166 ndx = 0; 167 } 168 169 if (ndx == 0 || mem2 + ndx > MULTIBOOT_SEARCH) { 170 #ifdef VERBOSE 171 (void) fprintf(stderr, "%s: %s: Didn't find multiboot2 " 172 "header\n", pname, fname); 173 #endif 174 mbh2 = NULL; 175 } 176 177 /* 178 * Find the 1:1 mapped PT_LOAD section 179 */ 180 for (ndx = 0; ndx < eh->e_phnum; ndx++) { 181 /*LINTED [ELF program header alignment]*/ 182 phdr = (Elf64_Phdr *)(phdrs + eh->e_phentsize * ndx); 183 184 /* 185 * Find the low memory 1:1 PT_LOAD section! 186 */ 187 if (phdr->p_type != PT_LOAD) 188 continue; 189 190 if (phdr->p_memsz == 0) 191 continue; 192 193 if (phdr->p_paddr != phdr->p_vaddr) 194 continue; 195 196 /* 197 * Make sure the multiboot header is part of the first PT_LOAD 198 * segment, and that the executables entry point starts at the 199 * same segment. 200 */ 201 if ((mem < phdr->p_offset) || 202 (mem >= (phdr->p_offset + phdr->p_filesz))) { 203 (void) fprintf(stderr, "%s: %s: identity mapped " 204 "PT_LOAD wasn't 1st PT_LOAD\n", pname, fname); 205 return (1); 206 } 207 if (eh->e_entry != phdr->p_paddr) { 208 (void) fprintf(stderr, "%s: %s: entry != paddr\n", 209 pname, fname); 210 return (1); 211 } 212 213 if (mbh2 != NULL && ((mem2 < phdr->p_offset) || 214 (mem2 >= (phdr->p_offset + phdr->p_filesz)))) { 215 #ifdef VERBOSE 216 (void) fprintf(stderr, "%s: %s: multiboot2 header not" 217 " in 1st PT_LOAD\n", pname, fname); 218 #endif 219 mem2 = 0; 220 mbh2 = NULL; 221 } 222 223 /* 224 * Patch the multiboot header fields to get entire file loaded. 225 * Grub uses the MB header for 64 bit loading. 226 */ 227 mbh->load_addr = phdr->p_paddr - phdr->p_offset; 228 mbh->entry_addr = phdr->p_paddr; 229 mbh->header_addr = mbh->load_addr + mem; 230 #ifdef VERBOSE 231 (void) printf(" %s: ELF64 MB header patched\n", fname); 232 (void) printf("\tload_addr now: 0x%x\n", mbh->load_addr); 233 (void) printf("\tentry_addr now: 0x%x\n", mbh->entry_addr); 234 (void) printf("\theader_addr now: 0x%x\n", mbh->header_addr); 235 #endif 236 if (mbh2 != NULL) 237 return (patch64_mb2(mbh2, mem2, phdr->p_paddr, 238 phdr->p_offset)); 239 return (0); 240 } 241 242 (void) fprintf(stderr, "%s: %s: Didn't find 1:1 mapped PT_LOAD " 243 "section\n", pname, fname); 244 return (1); 245 } 246 247 int 248 main(int argc, char **argv) 249 { 250 int fd; 251 uchar_t *ident; 252 void *hdr = NULL; 253 struct stat sb; 254 255 /* 256 * We expect one argument -- the elf file. 257 */ 258 if (argc != 2) { 259 (void) fprintf(stderr, "usage: %s <unix-elf-file>\n", argv[0]); 260 return (1); 261 } 262 263 pname = strrchr(argv[0], '/'); 264 if (pname == NULL) 265 pname = argv[0]; 266 else 267 ++pname; 268 269 fname = argv[1]; 270 if ((fd = open(fname, O_RDWR)) < 0) { 271 (void) fprintf(stderr, "%s: open(%s, O_RDWR) failed: %s\n", 272 pname, fname, strerror(errno)); 273 return (1); 274 } 275 276 if (fstat(fd, &sb) != 0) { 277 (void) fprintf(stderr, "%s: fstat failed: %s\n", 278 pname, strerror(errno)); 279 return (1); 280 } 281 282 /* Make sure we have at least MULTIBOOT_SEARCH bytes. */ 283 if (sb.st_size < MULTIBOOT_SEARCH) { 284 (void) fprintf(stderr, "%s: %s is too small for a kernel\n", 285 pname, fname); 286 return (1); 287 } 288 289 /* 290 * mmap the 1st 32K -- MB1 header is within first 8k and MB2 header 291 * is within 32k. 292 */ 293 image = mmap(NULL, MULTIBOOT_SEARCH, PROT_READ | PROT_WRITE, 294 MAP_SHARED, fd, 0); 295 if (image == MAP_FAILED) { 296 (void) fprintf(stderr, "%s: mmap() of %s failed: %s\n", 297 pname, fname, strerror(errno)); 298 return (1); 299 } 300 301 ident = ELFSEEK(0); 302 if (ident[EI_MAG0] != ELFMAG0 || ident[EI_MAG1] != ELFMAG1 || 303 ident[EI_MAG2] != ELFMAG2 || ident[EI_MAG3] != ELFMAG3) { 304 (void) fprintf(stderr, "%s: %s: not an ELF file!\n", pname, 305 fname); 306 return (1); 307 } 308 309 if (ident[EI_CLASS] == ELFCLASS64) { 310 hdr = ELFSEEK(0); 311 return (patch64(hdr)); 312 } 313 if (ident[EI_CLASS] != ELFCLASS32) { 314 (void) fprintf(stderr, "%s: Unknown ELF class 0x%x\n", pname, 315 ident[EI_CLASS]); 316 return (1); 317 } 318 return (0); 319 } 320