xref: /openbmc/u-boot/tools/mkenvimage.c (revision d59c33a1)
1 /*
2  * (C) Copyright 2011 Free Electrons
3  * David Wagner <david.wagner@free-electrons.com>
4  *
5  * Inspired from envcrc.c:
6  * (C) Copyright 2001
7  * Paolo Scaffardi, AIRVENT SAM s.p.a - RIMINI(ITALY), arsenio@tin.it
8  *
9  * See file CREDITS for list of people who contributed to this
10  * project.
11  *
12  * This program is free software; you can redistribute it and/or
13  * modify it under the terms of the GNU General Public License as
14  * published by the Free Software Foundation; either version 2 of
15  * the License, or (at your option) any later version.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  * GNU General Public License for more details.
21  *
22  * You should have received a copy of the GNU General Public License
23  * along with this program; if not, write to the Free Software
24  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
25  * MA 02111-1307 USA
26  */
27 
28 #include <errno.h>
29 #include <fcntl.h>
30 #include <stdio.h>
31 #include <stdint.h>
32 #include <string.h>
33 #include <unistd.h>
34 #include <compiler.h>
35 #include <sys/types.h>
36 #include <sys/stat.h>
37 
38 #include <u-boot/crc.h>
39 
40 #define CRC_SIZE sizeof(uint32_t)
41 
42 static void usage(const char *exec_name)
43 {
44 	fprintf(stderr, "%s [-h] [-r] [-b] [-p <byte>] "
45 	       "-s <environment partition size> -o <output> <input file>\n"
46 	       "\n"
47 	       "This tool takes a key=value input file (same as would a "
48 	       "`printenv' show) and generates the corresponding environment "
49 	       "image, ready to be flashed.\n"
50 	       "\n"
51 	       "\tThe input file is in format:\n"
52 	       "\t\tkey1=value1\n"
53 	       "\t\tkey2=value2\n"
54 	       "\t\t...\n"
55 	       "\t-r : the environment has multiple copies in flash\n"
56 	       "\t-b : the target is big endian (default is little endian)\n"
57 	       "\t-p <byte> : fill the image with <byte> bytes instead of "
58 	       "0xff bytes\n"
59 	       "\n"
60 	       "If the input file is \"-\", data is read from standard input\n",
61 	       exec_name);
62 }
63 
64 int main(int argc, char **argv)
65 {
66 	uint32_t crc, targetendian_crc;
67 	const char *txt_filename = NULL, *bin_filename = NULL;
68 	int txt_fd, bin_fd;
69 	unsigned char *dataptr, *envptr;
70 	unsigned char *filebuf = NULL;
71 	unsigned int filesize = 0, envsize = 0, datasize = 0;
72 	int bigendian = 0;
73 	int redundant = 0;
74 	unsigned char padbyte = 0xff;
75 
76 	int option;
77 	int ret = EXIT_SUCCESS;
78 
79 	struct stat txt_file_stat;
80 
81 	int fp, ep;
82 
83 	/* Parse the cmdline */
84 	while ((option = getopt(argc, argv, "s:o:rbp:h")) != -1) {
85 		switch (option) {
86 		case 's':
87 			datasize = strtol(optarg, NULL, 0);
88 			break;
89 		case 'o':
90 			bin_filename = strdup(optarg);
91 			if (!bin_filename) {
92 				fprintf(stderr, "Can't strdup() the output "
93 						"filename\n");
94 				return EXIT_FAILURE;
95 			}
96 			break;
97 		case 'r':
98 			redundant = 1;
99 			break;
100 		case 'b':
101 			bigendian = 1;
102 			break;
103 		case 'p':
104 			padbyte = strtol(optarg, NULL, 0);
105 			break;
106 		case 'h':
107 			usage(argv[0]);
108 			return EXIT_SUCCESS;
109 		default:
110 			fprintf(stderr, "Wrong option -%c\n", option);
111 			usage(argv[0]);
112 			return EXIT_FAILURE;
113 		}
114 	}
115 
116 	/* Check datasize and allocate the data */
117 	if (datasize == 0) {
118 		fprintf(stderr,
119 			"Please specify the size of the envrionnment "
120 			"partition.\n");
121 		usage(argv[0]);
122 		return EXIT_FAILURE;
123 	}
124 
125 	dataptr = malloc(datasize * sizeof(*dataptr));
126 	if (!dataptr) {
127 		fprintf(stderr, "Can't alloc dataptr.\n");
128 		return EXIT_FAILURE;
129 	}
130 
131 	/*
132 	 * envptr points to the beginning of the actual environment (after the
133 	 * crc and possible `redundant' bit
134 	 */
135 	envsize = datasize - (CRC_SIZE + redundant);
136 	envptr = dataptr + CRC_SIZE + redundant;
137 
138 	/* Pad the environment with the padding byte */
139 	memset(envptr, padbyte, envsize);
140 
141 	/* Open the input file ... */
142 	if (optind >= argc) {
143 		fprintf(stderr, "Please specify an input filename\n");
144 		return EXIT_FAILURE;
145 	}
146 
147 	txt_filename = argv[optind];
148 	if (strcmp(txt_filename, "-") == 0) {
149 		int readbytes = 0;
150 		int readlen = sizeof(*envptr) * 2048;
151 		txt_fd = STDIN_FILENO;
152 
153 		do {
154 			filebuf = realloc(filebuf, readlen);
155 			readbytes = read(txt_fd, filebuf + filesize, readlen);
156 			filesize += readbytes;
157 		} while (readbytes == readlen);
158 
159 	} else {
160 		txt_fd = open(txt_filename, O_RDONLY);
161 		if (txt_fd == -1) {
162 			fprintf(stderr, "Can't open \"%s\": %s\n",
163 					txt_filename, strerror(errno));
164 			return EXIT_FAILURE;
165 		}
166 		/* ... and check it */
167 		ret = fstat(txt_fd, &txt_file_stat);
168 		if (ret == -1) {
169 			fprintf(stderr, "Can't stat() on \"%s\": "
170 					"%s\n", txt_filename, strerror(errno));
171 			return EXIT_FAILURE;
172 		}
173 
174 		filesize = txt_file_stat.st_size;
175 		/* Read the raw input file and transform it */
176 		filebuf = malloc(sizeof(*envptr) * filesize);
177 		ret = read(txt_fd, filebuf, sizeof(*envptr) * filesize);
178 		if (ret != sizeof(*envptr) * filesize) {
179 			fprintf(stderr, "Can't read the whole input file\n");
180 			return EXIT_FAILURE;
181 		}
182 		ret = close(txt_fd);
183 	}
184 	/*
185 	 * The right test to do is "=>" (not ">") because of the additionnal
186 	 * ending \0. See below.
187 	 */
188 	if (filesize >= envsize) {
189 		fprintf(stderr, "The input file is larger than the "
190 				"envrionnment partition size\n");
191 		return EXIT_FAILURE;
192 	}
193 
194 	/* Replace newlines separating variables with \0 */
195 	for (fp = 0, ep = 0 ; fp < filesize ; fp++) {
196 		if (filebuf[fp] == '\n') {
197 			if (fp == 0) {
198 				/*
199 				 * Newline at the beggining of the file ?
200 				 * Ignore it.
201 				 */
202 				continue;
203 			} else if (filebuf[fp-1] == '\\') {
204 				/*
205 				 * Embedded newline in a variable.
206 				 *
207 				 * The backslash was added to the envptr ;
208 				 * rewind and replace it with a newline
209 				 */
210 				ep--;
211 				envptr[ep++] = '\n';
212 			} else {
213 				/* End of a variable */
214 				envptr[ep++] = '\0';
215 			}
216 		} else if (filebuf[fp] == '#') {
217 			if (fp != 0 && filebuf[fp-1] == '\n') {
218 				/* This line is a comment, let's skip it */
219 				while (fp < txt_file_stat.st_size && fp++ &&
220 				       filebuf[fp] != '\n');
221 			} else {
222 				envptr[ep++] = filebuf[fp];
223 			}
224 		} else {
225 			envptr[ep++] = filebuf[fp];
226 		}
227 	}
228 	/*
229 	 * Make sure there is a final '\0'
230 	 * And do it again on the next byte to mark the end of the environment.
231 	 */
232 	if (envptr[ep-1] != '\0') {
233 		envptr[ep++] = '\0';
234 		/*
235 		 * The text file doesn't have an ending newline.  We need to
236 		 * check the env size again to make sure we have room for two \0
237 		 */
238 		if (ep >= envsize) {
239 			fprintf(stderr, "The environment file is too large for "
240 					"the target environment storage\n");
241 			return EXIT_FAILURE;
242 		}
243 		envptr[ep] = '\0';
244 	} else {
245 		envptr[ep] = '\0';
246 	}
247 
248 	/* Computes the CRC and put it at the beginning of the data */
249 	crc = crc32(0, envptr, envsize);
250 	targetendian_crc = bigendian ? cpu_to_be32(crc) : cpu_to_le32(crc);
251 
252 	memcpy(dataptr, &targetendian_crc, sizeof(uint32_t));
253 
254 	bin_fd = creat(bin_filename, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
255 	if (bin_fd == -1) {
256 		fprintf(stderr, "Can't open output file \"%s\": %s\n",
257 				bin_filename, strerror(errno));
258 		return EXIT_FAILURE;
259 	}
260 
261 	if (write(bin_fd, dataptr, sizeof(*dataptr) * datasize) !=
262 			sizeof(*dataptr) * datasize) {
263 		fprintf(stderr, "write() failed: %s\n", strerror(errno));
264 		return EXIT_FAILURE;
265 	}
266 
267 	ret = close(bin_fd);
268 
269 	return ret;
270 }
271