xref: /openbmc/u-boot/env/common.c (revision fbe502e9) 
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2000-2010
4  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5  *
6  * (C) Copyright 2001 Sysgo Real-Time Solutions, GmbH <www.elinos.com>
7  * Andreas Heppel <aheppel@sysgo.de>
8  */
9 
10 #include <common.h>
11 #include <command.h>
12 #include <environment.h>
13 #include <linux/stddef.h>
14 #include <search.h>
15 #include <errno.h>
16 #include <malloc.h>
17 
18 DECLARE_GLOBAL_DATA_PTR;
19 
20 /************************************************************************
21  * Default settings to be used when no valid environment is found
22  */
23 #include <env_default.h>
24 
25 struct hsearch_data env_htab = {
26 	.change_ok = env_flags_validate,
27 };
28 
29 /*
30  * Read an environment variable as a boolean
31  * Return -1 if variable does not exist (default to true)
32  */
33 int env_get_yesno(const char *var)
34 {
35 	char *s = env_get(var);
36 
37 	if (s == NULL)
38 		return -1;
39 	return (*s == '1' || *s == 'y' || *s == 'Y' || *s == 't' || *s == 'T') ?
40 		1 : 0;
41 }
42 
43 /*
44  * Look up the variable from the default environment
45  */
46 char *env_get_default(const char *name)
47 {
48 	char *ret_val;
49 	unsigned long really_valid = gd->env_valid;
50 	unsigned long real_gd_flags = gd->flags;
51 
52 	/* Pretend that the image is bad. */
53 	gd->flags &= ~GD_FLG_ENV_READY;
54 	gd->env_valid = ENV_INVALID;
55 	ret_val = env_get(name);
56 	gd->env_valid = really_valid;
57 	gd->flags = real_gd_flags;
58 	return ret_val;
59 }
60 
61 void set_default_env(const char *s)
62 {
63 	int flags = 0;
64 
65 	if (sizeof(default_environment) > ENV_SIZE) {
66 		puts("*** Error - default environment is too large\n\n");
67 		return;
68 	}
69 
70 	if (s) {
71 		if (*s == '!') {
72 			printf("*** Warning - %s, "
73 				"using default environment\n\n",
74 				s + 1);
75 		} else {
76 			flags = H_INTERACTIVE;
77 			puts(s);
78 		}
79 	} else {
80 		debug("Using default environment\n");
81 	}
82 
83 	if (himport_r(&env_htab, (char *)default_environment,
84 			sizeof(default_environment), '\0', flags, 0,
85 			0, NULL) == 0)
86 		pr_err("Environment import failed: errno = %d\n", errno);
87 
88 	gd->flags |= GD_FLG_ENV_READY;
89 	gd->flags |= GD_FLG_ENV_DEFAULT;
90 }
91 
92 
93 /* [re]set individual variables to their value in the default environment */
94 int set_default_vars(int nvars, char * const vars[])
95 {
96 	/*
97 	 * Special use-case: import from default environment
98 	 * (and use \0 as a separator)
99 	 */
100 	return himport_r(&env_htab, (const char *)default_environment,
101 				sizeof(default_environment), '\0',
102 				H_NOCLEAR | H_INTERACTIVE, 0, nvars, vars);
103 }
104 
105 /*
106  * Check if CRC is valid and (if yes) import the environment.
107  * Note that "buf" may or may not be aligned.
108  */
109 int env_import(const char *buf, int check)
110 {
111 	env_t *ep = (env_t *)buf;
112 
113 	if (check) {
114 		uint32_t crc;
115 
116 		memcpy(&crc, &ep->crc, sizeof(crc));
117 
118 		if (crc32(0, ep->data, ENV_SIZE) != crc) {
119 			set_default_env("!bad CRC");
120 			return -EIO;
121 		}
122 	}
123 
124 	if (himport_r(&env_htab, (char *)ep->data, ENV_SIZE, '\0', 0, 0,
125 			0, NULL)) {
126 		gd->flags |= GD_FLG_ENV_READY;
127 		return 0;
128 	}
129 
130 	pr_err("Cannot import environment: errno = %d\n", errno);
131 
132 	set_default_env("!import failed");
133 
134 	return -EIO;
135 }
136 
137 #ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
138 static unsigned char env_flags;
139 
140 int env_import_redund(const char *buf1, int buf1_read_fail,
141 		      const char *buf2, int buf2_read_fail)
142 {
143 	int crc1_ok, crc2_ok;
144 	env_t *ep, *tmp_env1, *tmp_env2;
145 
146 	tmp_env1 = (env_t *)buf1;
147 	tmp_env2 = (env_t *)buf2;
148 
149 	if (buf1_read_fail && buf2_read_fail) {
150 		puts("*** Error - No Valid Environment Area found\n");
151 	} else if (buf1_read_fail || buf2_read_fail) {
152 		puts("*** Warning - some problems detected ");
153 		puts("reading environment; recovered successfully\n");
154 	}
155 
156 	if (buf1_read_fail && buf2_read_fail) {
157 		set_default_env("!bad env area");
158 		return -EIO;
159 	} else if (!buf1_read_fail && buf2_read_fail) {
160 		gd->env_valid = ENV_VALID;
161 		return env_import((char *)tmp_env1, 1);
162 	} else if (buf1_read_fail && !buf2_read_fail) {
163 		gd->env_valid = ENV_REDUND;
164 		return env_import((char *)tmp_env2, 1);
165 	}
166 
167 	crc1_ok = crc32(0, tmp_env1->data, ENV_SIZE) ==
168 			tmp_env1->crc;
169 	crc2_ok = crc32(0, tmp_env2->data, ENV_SIZE) ==
170 			tmp_env2->crc;
171 
172 	if (!crc1_ok && !crc2_ok) {
173 		set_default_env("!bad CRC");
174 		return -EIO;
175 	} else if (crc1_ok && !crc2_ok) {
176 		gd->env_valid = ENV_VALID;
177 	} else if (!crc1_ok && crc2_ok) {
178 		gd->env_valid = ENV_REDUND;
179 	} else {
180 		/* both ok - check serial */
181 		if (tmp_env1->flags == 255 && tmp_env2->flags == 0)
182 			gd->env_valid = ENV_REDUND;
183 		else if (tmp_env2->flags == 255 && tmp_env1->flags == 0)
184 			gd->env_valid = ENV_VALID;
185 		else if (tmp_env1->flags > tmp_env2->flags)
186 			gd->env_valid = ENV_VALID;
187 		else if (tmp_env2->flags > tmp_env1->flags)
188 			gd->env_valid = ENV_REDUND;
189 		else /* flags are equal - almost impossible */
190 			gd->env_valid = ENV_VALID;
191 	}
192 
193 	if (gd->env_valid == ENV_VALID)
194 		ep = tmp_env1;
195 	else
196 		ep = tmp_env2;
197 
198 	env_flags = ep->flags;
199 	return env_import((char *)ep, 0);
200 }
201 #endif /* CONFIG_SYS_REDUNDAND_ENVIRONMENT */
202 
203 /* Export the environment and generate CRC for it. */
204 int env_export(env_t *env_out)
205 {
206 	char *res;
207 	ssize_t	len;
208 
209 	res = (char *)env_out->data;
210 	len = hexport_r(&env_htab, '\0', 0, &res, ENV_SIZE, 0, NULL);
211 	if (len < 0) {
212 		pr_err("Cannot export environment: errno = %d\n", errno);
213 		return 1;
214 	}
215 
216 	env_out->crc = crc32(0, env_out->data, ENV_SIZE);
217 
218 #ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
219 	env_out->flags = ++env_flags; /* increase the serial */
220 #endif
221 
222 	return 0;
223 }
224 
225 void env_relocate(void)
226 {
227 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
228 	env_reloc();
229 	env_fix_drivers();
230 	env_htab.change_ok += gd->reloc_off;
231 #endif
232 	if (gd->env_valid == ENV_INVALID) {
233 #if defined(CONFIG_ENV_IS_NOWHERE) || defined(CONFIG_SPL_BUILD)
234 		/* Environment not changable */
235 		set_default_env(NULL);
236 #else
237 		bootstage_error(BOOTSTAGE_ID_NET_CHECKSUM);
238 		set_default_env("!bad CRC");
239 #endif
240 	} else {
241 		env_load();
242 	}
243 }
244 
245 #if defined(CONFIG_AUTO_COMPLETE) && !defined(CONFIG_SPL_BUILD)
246 int env_complete(char *var, int maxv, char *cmdv[], int bufsz, char *buf)
247 {
248 	ENTRY *match;
249 	int found, idx;
250 
251 	idx = 0;
252 	found = 0;
253 	cmdv[0] = NULL;
254 
255 	while ((idx = hmatch_r(var, idx, &match, &env_htab))) {
256 		int vallen = strlen(match->key) + 1;
257 
258 		if (found >= maxv - 2 || bufsz < vallen)
259 			break;
260 
261 		cmdv[found++] = buf;
262 		memcpy(buf, match->key, vallen);
263 		buf += vallen;
264 		bufsz -= vallen;
265 	}
266 
267 	qsort(cmdv, found, sizeof(cmdv[0]), strcmp_compar);
268 
269 	if (idx)
270 		cmdv[found++] = "...";
271 
272 	cmdv[found] = NULL;
273 	return found;
274 }
275 #endif
276