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
patch64_mb2(multiboot2_header_t * mbh2,int file_offset,Elf64_Addr ptload_start,Elf32_Off ptload_offset)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
patch64(Elf64_Ehdr * eh)105 patch64(Elf64_Ehdr *eh)
106 {
107 Elf64_Phdr *phdr;
108 caddr_t phdrs = NULL;
109 int 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
main(int argc,char ** argv)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