xref: /openbmc/u-boot/tools/mkenvimage.c (revision 87a62bce)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2011 Free Electrons
4  * David Wagner <david.wagner@free-electrons.com>
5  *
6  * Inspired from envcrc.c:
7  * (C) Copyright 2001
8  * Paolo Scaffardi, AIRVENT SAM s.p.a - RIMINI(ITALY), arsenio@tin.it
9  */
10 
11 #include <errno.h>
12 #include <fcntl.h>
13 #include <stdio.h>
14 #include <stdlib.h>
15 #include <stdint.h>
16 #include <string.h>
17 #include <unistd.h>
18 #include <libgen.h>
19 #include <sys/types.h>
20 #include <sys/stat.h>
21 #include <sys/mman.h>
22 
23 #include "compiler.h"
24 #include <u-boot/crc.h>
25 #include <version.h>
26 
27 #define CRC_SIZE sizeof(uint32_t)
28 
29 static void usage(const char *exec_name)
30 {
31 	fprintf(stderr, "%s [-h] [-r] [-b] [-p <byte>] -s <environment partition size> -o <output> <input file>\n"
32 	       "\n"
33 	       "This tool takes a key=value input file (same as would a `printenv' show) and generates the corresponding environment image, ready to be flashed.\n"
34 	       "\n"
35 	       "\tThe input file is in format:\n"
36 	       "\t\tkey1=value1\n"
37 	       "\t\tkey2=value2\n"
38 	       "\t\t...\n"
39 	       "\tEmpty lines are skipped, and lines with a # in the first\n"
40 	       "\tcolumn are treated as comments (also skipped).\n"
41 	       "\t-r : the environment has multiple copies in flash\n"
42 	       "\t-b : the target is big endian (default is little endian)\n"
43 	       "\t-p <byte> : fill the image with <byte> bytes instead of 0xff bytes\n"
44 	       "\t-V : print version information and exit\n"
45 	       "\n"
46 	       "If the input file is \"-\", data is read from standard input\n",
47 	       exec_name);
48 }
49 
50 long int xstrtol(const char *s)
51 {
52 	long int tmp;
53 
54 	errno = 0;
55 	tmp = strtol(s, NULL, 0);
56 	if (!errno)
57 		return tmp;
58 
59 	if (errno == ERANGE)
60 		fprintf(stderr, "Bad integer format: %s\n",  s);
61 	else
62 		fprintf(stderr, "Error while parsing %s: %s\n", s,
63 				strerror(errno));
64 
65 	exit(EXIT_FAILURE);
66 }
67 
68 int main(int argc, char **argv)
69 {
70 	uint32_t crc, targetendian_crc;
71 	const char *txt_filename = NULL, *bin_filename = NULL;
72 	int txt_fd, bin_fd;
73 	unsigned char *dataptr, *envptr;
74 	unsigned char *filebuf = NULL;
75 	unsigned int filesize = 0, envsize = 0, datasize = 0;
76 	int bigendian = 0;
77 	int redundant = 0;
78 	unsigned char padbyte = 0xff;
79 
80 	int option;
81 	int ret = EXIT_SUCCESS;
82 
83 	struct stat txt_file_stat;
84 
85 	int fp, ep;
86 	const char *prg;
87 
88 	prg = basename(argv[0]);
89 
90 	/* Turn off getopt()'s internal error message */
91 	opterr = 0;
92 
93 	/* Parse the cmdline */
94 	while ((option = getopt(argc, argv, ":s:o:rbp:hV")) != -1) {
95 		switch (option) {
96 		case 's':
97 			datasize = xstrtol(optarg);
98 			break;
99 		case 'o':
100 			bin_filename = strdup(optarg);
101 			if (!bin_filename) {
102 				fprintf(stderr, "Can't strdup() the output filename\n");
103 				return EXIT_FAILURE;
104 			}
105 			break;
106 		case 'r':
107 			redundant = 1;
108 			break;
109 		case 'b':
110 			bigendian = 1;
111 			break;
112 		case 'p':
113 			padbyte = xstrtol(optarg);
114 			break;
115 		case 'h':
116 			usage(prg);
117 			return EXIT_SUCCESS;
118 		case 'V':
119 			printf("%s version %s\n", prg, PLAIN_VERSION);
120 			return EXIT_SUCCESS;
121 		case ':':
122 			fprintf(stderr, "Missing argument for option -%c\n",
123 				optopt);
124 			usage(prg);
125 			return EXIT_FAILURE;
126 		default:
127 			fprintf(stderr, "Wrong option -%c\n", optopt);
128 			usage(prg);
129 			return EXIT_FAILURE;
130 		}
131 	}
132 
133 	/* Check datasize and allocate the data */
134 	if (datasize == 0) {
135 		fprintf(stderr, "Please specify the size of the environment partition.\n");
136 		usage(prg);
137 		return EXIT_FAILURE;
138 	}
139 
140 	dataptr = malloc(datasize * sizeof(*dataptr));
141 	if (!dataptr) {
142 		fprintf(stderr, "Can't alloc %d bytes for dataptr.\n",
143 				datasize);
144 		return EXIT_FAILURE;
145 	}
146 
147 	/*
148 	 * envptr points to the beginning of the actual environment (after the
149 	 * crc and possible `redundant' byte
150 	 */
151 	envsize = datasize - (CRC_SIZE + redundant);
152 	envptr = dataptr + CRC_SIZE + redundant;
153 
154 	/* Pad the environment with the padding byte */
155 	memset(envptr, padbyte, envsize);
156 
157 	/* Open the input file ... */
158 	if (optind >= argc || strcmp(argv[optind], "-") == 0) {
159 		int readbytes = 0;
160 		int readlen = sizeof(*envptr) * 4096;
161 		txt_fd = STDIN_FILENO;
162 
163 		do {
164 			filebuf = realloc(filebuf, filesize + readlen);
165 			if (!filebuf) {
166 				fprintf(stderr, "Can't realloc memory for the input file buffer\n");
167 				return EXIT_FAILURE;
168 			}
169 			readbytes = read(txt_fd, filebuf + filesize, readlen);
170 			if (readbytes < 0) {
171 				fprintf(stderr, "Error while reading stdin: %s\n",
172 						strerror(errno));
173 				return EXIT_FAILURE;
174 			}
175 			filesize += readbytes;
176 		} while (readbytes == readlen);
177 
178 	} else {
179 		txt_filename = argv[optind];
180 		txt_fd = open(txt_filename, O_RDONLY);
181 		if (txt_fd == -1) {
182 			fprintf(stderr, "Can't open \"%s\": %s\n",
183 					txt_filename, strerror(errno));
184 			return EXIT_FAILURE;
185 		}
186 		/* ... and check it */
187 		ret = fstat(txt_fd, &txt_file_stat);
188 		if (ret == -1) {
189 			fprintf(stderr, "Can't stat() on \"%s\": %s\n",
190 					txt_filename, strerror(errno));
191 			return EXIT_FAILURE;
192 		}
193 
194 		filesize = txt_file_stat.st_size;
195 
196 		filebuf = mmap(NULL, sizeof(*envptr) * filesize, PROT_READ,
197 			       MAP_PRIVATE, txt_fd, 0);
198 		if (filebuf == MAP_FAILED) {
199 			fprintf(stderr, "mmap (%zu bytes) failed: %s\n",
200 					sizeof(*envptr) * filesize,
201 					strerror(errno));
202 			fprintf(stderr, "Falling back to read()\n");
203 
204 			filebuf = malloc(sizeof(*envptr) * filesize);
205 			ret = read(txt_fd, filebuf, sizeof(*envptr) * filesize);
206 			if (ret != sizeof(*envptr) * filesize) {
207 				fprintf(stderr, "Can't read the whole input file (%zu bytes): %s\n",
208 					sizeof(*envptr) * filesize,
209 					strerror(errno));
210 
211 				return EXIT_FAILURE;
212 			}
213 		}
214 		ret = close(txt_fd);
215 	}
216 
217 	/* Parse a byte at time until reaching the file OR until the environment fills
218 	 * up. Check ep against envsize - 1 to allow for extra trailing '\0'. */
219 	for (fp = 0, ep = 0 ; fp < filesize && ep < envsize - 1; fp++) {
220 		if (filebuf[fp] == '\n') {
221 			if (fp == 0 || filebuf[fp-1] == '\n') {
222 				/*
223 				 * Skip empty lines.
224 				 */
225 				continue;
226 			} else if (filebuf[fp-1] == '\\') {
227 				/*
228 				 * Embedded newline in a variable.
229 				 *
230 				 * The backslash was added to the envptr; rewind
231 				 * and replace it with a newline
232 				 */
233 				ep--;
234 				envptr[ep++] = '\n';
235 			} else {
236 				/* End of a variable */
237 				envptr[ep++] = '\0';
238 			}
239 		} else if ((fp == 0 || filebuf[fp-1] == '\n') && filebuf[fp] == '#') {
240 			/* Comment, skip the line. */
241 			while (++fp < filesize && filebuf[fp] != '\n')
242 			continue;
243 		} else {
244 			envptr[ep++] = filebuf[fp];
245 		}
246 	}
247 	/* If there are more bytes in the file still, it means the env filled up
248 	 * before parsing the whole file.  Eat comments & whitespace here to see if
249 	 * there was anything meaning full left in the file, and if so, throw a error
250 	 * and exit. */
251 	for( ; fp < filesize; fp++ )
252 	{
253 		if (filebuf[fp] == '\n') {
254 			if (fp == 0 || filebuf[fp-1] == '\n') {
255 				/* Ignore blank lines */
256 				continue;
257 			}
258 		} else if ((fp == 0 || filebuf[fp-1] == '\n') && filebuf[fp] == '#') {
259 			while (++fp < filesize && filebuf[fp] != '\n')
260 			continue;
261 		} else {
262 			fprintf(stderr, "The environment file is too large for the target environment storage\n");
263 			return EXIT_FAILURE;
264 		}
265 	}
266 	/*
267 	 * Make sure there is a final '\0'
268 	 * And do it again on the next byte to mark the end of the environment.
269 	 */
270 	if (envptr[ep-1] != '\0') {
271 		envptr[ep++] = '\0';
272 		/*
273 		 * The text file doesn't have an ending newline.  We need to
274 		 * check the env size again to make sure we have room for two \0
275 		 */
276 		if (ep >= envsize) {
277 			fprintf(stderr, "The environment file is too large for the target environment storage\n");
278 			return EXIT_FAILURE;
279 		}
280 		envptr[ep] = '\0';
281 	} else {
282 		envptr[ep] = '\0';
283 	}
284 
285 	/* Computes the CRC and put it at the beginning of the data */
286 	crc = crc32(0, envptr, envsize);
287 	targetendian_crc = bigendian ? cpu_to_be32(crc) : cpu_to_le32(crc);
288 
289 	memcpy(dataptr, &targetendian_crc, sizeof(targetendian_crc));
290 	if (redundant)
291 		dataptr[sizeof(targetendian_crc)] = 1;
292 
293 	if (!bin_filename || strcmp(bin_filename, "-") == 0) {
294 		bin_fd = STDOUT_FILENO;
295 	} else {
296 		bin_fd = creat(bin_filename, S_IRUSR | S_IWUSR | S_IRGRP |
297 					     S_IWGRP);
298 		if (bin_fd == -1) {
299 			fprintf(stderr, "Can't open output file \"%s\": %s\n",
300 					bin_filename, strerror(errno));
301 			return EXIT_FAILURE;
302 		}
303 	}
304 
305 	if (write(bin_fd, dataptr, sizeof(*dataptr) * datasize) !=
306 			sizeof(*dataptr) * datasize) {
307 		fprintf(stderr, "write() failed: %s\n", strerror(errno));
308 		return EXIT_FAILURE;
309 	}
310 
311 	ret = close(bin_fd);
312 
313 	return ret;
314 }
315