xref: /rk3399_rockchip-uboot/env/common.c (revision 894688431927c1b73c64860c8aa71463c2593ea2) 
1 /*
2  * (C) Copyright 2000-2010
3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
4  *
5  * (C) Copyright 2001 Sysgo Real-Time Solutions, GmbH <www.elinos.com>
6  * Andreas Heppel <aheppel@sysgo.de>
7  *
8  * SPDX-License-Identifier:	GPL-2.0+
9  */
10 
11 #include <common.h>
12 #include <command.h>
13 #include <environment.h>
14 #include <linux/stddef.h>
15 #include <search.h>
16 #include <errno.h>
17 #include <malloc.h>
18 
19 DECLARE_GLOBAL_DATA_PTR;
20 
21 /************************************************************************
22  * Default settings to be used when no valid environment is found
23  */
24 #include <env_default.h>
25 
26 struct hsearch_data env_htab = {
27 	.change_ok = env_flags_validate,
28 };
29 
30 /*
31  * Read an environment variable as a boolean
32  * Return -1 if variable does not exist (default to true)
33  */
34 int env_get_yesno(const char *var)
35 {
36 	char *s = env_get(var);
37 
38 	if (s == NULL)
39 		return -1;
40 	return (*s == '1' || *s == 'y' || *s == 'Y' || *s == 't' || *s == 'T') ?
41 		1 : 0;
42 }
43 
44 __weak void board_env_fixup(void) {}
45 
46 /*
47  * Look up the variable from the default environment
48  */
49 char *env_get_default(const char *name)
50 {
51 	char *ret_val;
52 	unsigned long really_valid = gd->env_valid;
53 	unsigned long real_gd_flags = gd->flags;
54 
55 	/* Pretend that the image is bad. */
56 	gd->flags &= ~GD_FLG_ENV_READY;
57 	gd->env_valid = ENV_INVALID;
58 	ret_val = env_get(name);
59 	gd->env_valid = really_valid;
60 	gd->flags = real_gd_flags;
61 	return ret_val;
62 }
63 
64 void set_default_env(const char *s)
65 {
66 	int flags = 0;
67 
68 	if (sizeof(default_environment) > ENV_SIZE) {
69 		puts("*** Error - default environment is too large\n\n");
70 		return;
71 	}
72 
73 	if (s) {
74 		if (*s == '!') {
75 			printf("*** Warning - %s, "
76 				"using default environment\n\n",
77 				s + 1);
78 		} else {
79 			flags = H_INTERACTIVE;
80 			puts(s);
81 		}
82 	} else {
83 		puts("Using default environment\n\n");
84 	}
85 
86 	if (himport_r(&env_htab, (char *)default_environment,
87 			sizeof(default_environment), '\0', flags, 0,
88 			0, NULL) == 0)
89 		pr_err("Environment import failed: errno = %d\n", errno);
90 
91 	gd->flags |= GD_FLG_ENV_READY;
92 	gd->flags |= GD_FLG_ENV_DEFAULT;
93 
94 	board_env_fixup();
95 }
96 
97 
98 /* [re]set individual variables to their value in the default environment */
99 int set_default_vars(int nvars, char * const vars[])
100 {
101 	/*
102 	 * Special use-case: import from default environment
103 	 * (and use \0 as a separator)
104 	 */
105 	return himport_r(&env_htab, (const char *)default_environment,
106 				sizeof(default_environment), '\0',
107 				H_NOCLEAR | H_INTERACTIVE, 0, nvars, vars);
108 }
109 
110 int set_board_env(const char *vars, int size, int flags, bool ready)
111 {
112 	if (himport_r(&env_htab, (char *)vars, size, '\0',
113 		      flags, 0, 0, NULL) == 0) {
114 		pr_err("Environment import failed\n");
115 		return -1;
116 	}
117 
118 	if (ready) {
119 		gd->flags |= GD_FLG_ENV_READY;
120 		gd->flags |= GD_FLG_ENV_DEFAULT;
121 	}
122 
123 	return 0;
124 }
125 
126 #ifdef CONFIG_ENV_AES
127 #include <uboot_aes.h>
128 /**
129  * env_aes_cbc_get_key() - Get AES-128-CBC key for the environment
130  *
131  * This function shall return 16-byte array containing AES-128 key used
132  * to encrypt and decrypt the environment. This function must be overridden
133  * by the implementer as otherwise the environment encryption will not
134  * work.
135  */
136 __weak uint8_t *env_aes_cbc_get_key(void)
137 {
138 	return NULL;
139 }
140 
141 static int env_aes_cbc_crypt(env_t *env, const int enc)
142 {
143 	unsigned char *data = env->data;
144 	uint8_t *key;
145 	uint8_t key_exp[AES_EXPAND_KEY_LENGTH];
146 	uint32_t aes_blocks;
147 
148 	key = env_aes_cbc_get_key();
149 	if (!key)
150 		return -EINVAL;
151 
152 	/* First we expand the key. */
153 	aes_expand_key(key, key_exp);
154 
155 	/* Calculate the number of AES blocks to encrypt. */
156 	aes_blocks = ENV_SIZE / AES_KEY_LENGTH;
157 
158 	if (enc)
159 		aes_cbc_encrypt_blocks(key_exp, data, data, aes_blocks);
160 	else
161 		aes_cbc_decrypt_blocks(key_exp, data, data, aes_blocks);
162 
163 	return 0;
164 }
165 #else
166 static inline int env_aes_cbc_crypt(env_t *env, const int enc)
167 {
168 	return 0;
169 }
170 #endif
171 
172 /*
173  * Check if CRC is valid and (if yes) import the environment.
174  * Note that "buf" may or may not be aligned.
175  */
176 int env_import(const char *buf, int check)
177 {
178 	env_t *ep = (env_t *)buf;
179 	int ret;
180 
181 	if (check) {
182 		uint32_t crc;
183 
184 		memcpy(&crc, &ep->crc, sizeof(crc));
185 
186 		if (crc32(0, ep->data, ENV_SIZE) != crc) {
187 			set_default_env("!bad CRC");
188 			return 0;
189 		}
190 	}
191 
192 	/* Decrypt the env if desired. */
193 	ret = env_aes_cbc_crypt(ep, 0);
194 	if (ret) {
195 		pr_err("Failed to decrypt env!\n");
196 		set_default_env("!import failed");
197 		return ret;
198 	}
199 
200 	if (himport_r(&env_htab, (char *)ep->data, ENV_SIZE, '\0', 0, 0,
201 			0, NULL)) {
202 		gd->flags |= GD_FLG_ENV_READY;
203 		return 1;
204 	}
205 
206 	pr_err("Cannot import environment: errno = %d\n", errno);
207 
208 	set_default_env("!import failed");
209 
210 	return 0;
211 }
212 
213 #ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
214 static unsigned char env_flags;
215 
216 int env_import_redund(const char *buf1, const char *buf2)
217 {
218 	int crc1_ok, crc2_ok;
219 	env_t *ep, *tmp_env1, *tmp_env2;
220 
221 	tmp_env1 = (env_t *)buf1;
222 	tmp_env2 = (env_t *)buf2;
223 
224 	crc1_ok = crc32(0, tmp_env1->data, ENV_SIZE) ==
225 			tmp_env1->crc;
226 	crc2_ok = crc32(0, tmp_env2->data, ENV_SIZE) ==
227 			tmp_env2->crc;
228 
229 	if (!crc1_ok && !crc2_ok) {
230 		set_default_env("!bad CRC");
231 		return 0;
232 	} else if (crc1_ok && !crc2_ok) {
233 		gd->env_valid = ENV_VALID;
234 	} else if (!crc1_ok && crc2_ok) {
235 		gd->env_valid = ENV_REDUND;
236 	} else {
237 		/* both ok - check serial */
238 		if (tmp_env1->flags == 255 && tmp_env2->flags == 0)
239 			gd->env_valid = ENV_REDUND;
240 		else if (tmp_env2->flags == 255 && tmp_env1->flags == 0)
241 			gd->env_valid = ENV_VALID;
242 		else if (tmp_env1->flags > tmp_env2->flags)
243 			gd->env_valid = ENV_VALID;
244 		else if (tmp_env2->flags > tmp_env1->flags)
245 			gd->env_valid = ENV_REDUND;
246 		else /* flags are equal - almost impossible */
247 			gd->env_valid = ENV_VALID;
248 	}
249 
250 	if (gd->env_valid == ENV_VALID)
251 		ep = tmp_env1;
252 	else
253 		ep = tmp_env2;
254 
255 	env_flags = ep->flags;
256 	return env_import((char *)ep, 0);
257 }
258 #endif /* CONFIG_SYS_REDUNDAND_ENVIRONMENT */
259 
260 /* Export the environment and generate CRC for it. */
261 int env_export(env_t *env_out)
262 {
263 	char *res;
264 	ssize_t	len;
265 	int ret;
266 
267 	res = (char *)env_out->data;
268 	len = hexport_r(&env_htab, '\0', 0, &res, ENV_SIZE, 0, NULL);
269 	if (len < 0) {
270 		pr_err("Cannot export environment: errno = %d\n", errno);
271 		return 1;
272 	}
273 
274 	/* Encrypt the env if desired. */
275 	ret = env_aes_cbc_crypt(env_out, 1);
276 	if (ret)
277 		return ret;
278 
279 	env_out->crc = crc32(0, env_out->data, ENV_SIZE);
280 
281 #ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
282 	env_out->flags = ++env_flags; /* increase the serial */
283 #endif
284 
285 	return 0;
286 }
287 
288 void env_relocate(void)
289 {
290 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
291 	env_reloc();
292 	env_htab.change_ok += gd->reloc_off;
293 #endif
294 	if (gd->env_valid == ENV_INVALID) {
295 #if defined(CONFIG_ENV_IS_NOWHERE) || defined(CONFIG_SPL_BUILD)
296 		/* Environment not changable */
297 		set_default_env(NULL);
298 #else
299 		bootstage_error(BOOTSTAGE_ID_NET_CHECKSUM);
300 		set_default_env("!bad CRC");
301 #endif
302 	} else {
303 		env_load();
304 	}
305 }
306 
307 #if defined(CONFIG_AUTO_COMPLETE) && !defined(CONFIG_SPL_BUILD)
308 int env_complete(char *var, int maxv, char *cmdv[], int bufsz, char *buf)
309 {
310 	ENTRY *match;
311 	int found, idx;
312 
313 	idx = 0;
314 	found = 0;
315 	cmdv[0] = NULL;
316 
317 	while ((idx = hmatch_r(var, idx, &match, &env_htab))) {
318 		int vallen = strlen(match->key) + 1;
319 
320 		if (found >= maxv - 2 || bufsz < vallen)
321 			break;
322 
323 		cmdv[found++] = buf;
324 		memcpy(buf, match->key, vallen);
325 		buf += vallen;
326 		bufsz -= vallen;
327 	}
328 
329 	qsort(cmdv, found, sizeof(cmdv[0]), strcmp_compar);
330 
331 	if (idx)
332 		cmdv[found++] = "...";
333 
334 	cmdv[found] = NULL;
335 	return found;
336 }
337 #endif
338