1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * (C) Copyright 2000
4 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 */
6
7 #include <common.h>
8 #include <autoboot.h>
9 #include <bootretry.h>
10 #include <cli.h>
11 #include <console.h>
12 #include <fdtdec.h>
13 #include <menu.h>
14 #include <post.h>
15 #include <u-boot/sha256.h>
16 #include <bootcount.h>
17
18 DECLARE_GLOBAL_DATA_PTR;
19
20 #define MAX_DELAY_STOP_STR 32
21
22 #ifndef DEBUG_BOOTKEYS
23 #define DEBUG_BOOTKEYS 0
24 #endif
25 #define debug_bootkeys(fmt, args...) \
26 debug_cond(DEBUG_BOOTKEYS, fmt, ##args)
27
28 /* Stored value of bootdelay, used by autoboot_command() */
29 static int stored_bootdelay;
30
31 #if defined(CONFIG_AUTOBOOT_KEYED)
32 #if defined(CONFIG_AUTOBOOT_STOP_STR_SHA256)
33
34 /*
35 * Use a "constant-length" time compare function for this
36 * hash compare:
37 *
38 * https://crackstation.net/hashing-security.htm
39 */
slow_equals(u8 * a,u8 * b,int len)40 static int slow_equals(u8 *a, u8 *b, int len)
41 {
42 int diff = 0;
43 int i;
44
45 for (i = 0; i < len; i++)
46 diff |= a[i] ^ b[i];
47
48 return diff == 0;
49 }
50
passwd_abort(uint64_t etime)51 static int passwd_abort(uint64_t etime)
52 {
53 const char *sha_env_str = env_get("bootstopkeysha256");
54 u8 sha_env[SHA256_SUM_LEN];
55 u8 sha[SHA256_SUM_LEN];
56 char presskey[MAX_DELAY_STOP_STR];
57 const char *algo_name = "sha256";
58 u_int presskey_len = 0;
59 int abort = 0;
60 int size = sizeof(sha);
61 int ret;
62
63 if (sha_env_str == NULL)
64 sha_env_str = CONFIG_AUTOBOOT_STOP_STR_SHA256;
65
66 /*
67 * Generate the binary value from the environment hash value
68 * so that we can compare this value with the computed hash
69 * from the user input
70 */
71 ret = hash_parse_string(algo_name, sha_env_str, sha_env);
72 if (ret) {
73 printf("Hash %s not supported!\n", algo_name);
74 return 0;
75 }
76
77 /*
78 * We don't know how long the stop-string is, so we need to
79 * generate the sha256 hash upon each input character and
80 * compare the value with the one saved in the environment
81 */
82 do {
83 if (tstc()) {
84 /* Check for input string overflow */
85 if (presskey_len >= MAX_DELAY_STOP_STR)
86 return 0;
87
88 presskey[presskey_len++] = getc();
89
90 /* Calculate sha256 upon each new char */
91 hash_block(algo_name, (const void *)presskey,
92 presskey_len, sha, &size);
93
94 /* And check if sha matches saved value in env */
95 if (slow_equals(sha, sha_env, SHA256_SUM_LEN))
96 abort = 1;
97 }
98 } while (!abort && get_ticks() <= etime);
99
100 return abort;
101 }
102 #else
passwd_abort(uint64_t etime)103 static int passwd_abort(uint64_t etime)
104 {
105 int abort = 0;
106 struct {
107 char *str;
108 u_int len;
109 int retry;
110 }
111 delaykey[] = {
112 { .str = env_get("bootdelaykey"), .retry = 1 },
113 { .str = env_get("bootstopkey"), .retry = 0 },
114 };
115
116 char presskey[MAX_DELAY_STOP_STR];
117 u_int presskey_len = 0;
118 u_int presskey_max = 0;
119 u_int i;
120
121 # ifdef CONFIG_AUTOBOOT_DELAY_STR
122 if (delaykey[0].str == NULL)
123 delaykey[0].str = CONFIG_AUTOBOOT_DELAY_STR;
124 # endif
125 # ifdef CONFIG_AUTOBOOT_STOP_STR
126 if (delaykey[1].str == NULL)
127 delaykey[1].str = CONFIG_AUTOBOOT_STOP_STR;
128 # endif
129
130 for (i = 0; i < sizeof(delaykey) / sizeof(delaykey[0]); i++) {
131 delaykey[i].len = delaykey[i].str == NULL ?
132 0 : strlen(delaykey[i].str);
133 delaykey[i].len = delaykey[i].len > MAX_DELAY_STOP_STR ?
134 MAX_DELAY_STOP_STR : delaykey[i].len;
135
136 presskey_max = presskey_max > delaykey[i].len ?
137 presskey_max : delaykey[i].len;
138
139 debug_bootkeys("%s key:<%s>\n",
140 delaykey[i].retry ? "delay" : "stop",
141 delaykey[i].str ? delaykey[i].str : "NULL");
142 }
143
144 /* In order to keep up with incoming data, check timeout only
145 * when catch up.
146 */
147 do {
148 if (tstc()) {
149 if (presskey_len < presskey_max) {
150 presskey[presskey_len++] = getc();
151 } else {
152 for (i = 0; i < presskey_max - 1; i++)
153 presskey[i] = presskey[i + 1];
154
155 presskey[i] = getc();
156 }
157 }
158
159 for (i = 0; i < sizeof(delaykey) / sizeof(delaykey[0]); i++) {
160 if (delaykey[i].len > 0 &&
161 presskey_len >= delaykey[i].len &&
162 memcmp(presskey + presskey_len -
163 delaykey[i].len, delaykey[i].str,
164 delaykey[i].len) == 0) {
165 debug_bootkeys("got %skey\n",
166 delaykey[i].retry ? "delay" :
167 "stop");
168
169 /* don't retry auto boot */
170 if (!delaykey[i].retry)
171 bootretry_dont_retry();
172 abort = 1;
173 }
174 }
175 } while (!abort && get_ticks() <= etime);
176
177 return abort;
178 }
179 #endif
180
181 /***************************************************************************
182 * Watch for 'delay' seconds for autoboot stop or autoboot delay string.
183 * returns: 0 - no key string, allow autoboot 1 - got key string, abort
184 */
__abortboot(int bootdelay)185 static int __abortboot(int bootdelay)
186 {
187 int abort;
188 uint64_t etime = endtick(bootdelay);
189
190 # ifdef CONFIG_AUTOBOOT_PROMPT
191 /*
192 * CONFIG_AUTOBOOT_PROMPT includes the %d for all boards.
193 * To print the bootdelay value upon bootup.
194 */
195 printf(CONFIG_AUTOBOOT_PROMPT, bootdelay);
196 # endif
197
198 abort = passwd_abort(etime);
199 if (!abort)
200 debug_bootkeys("key timeout\n");
201
202 return abort;
203 }
204
205 # else /* !defined(CONFIG_AUTOBOOT_KEYED) */
206
207 #ifdef CONFIG_MENUKEY
208 static int menukey;
209 #endif
210
__abortboot(int bootdelay)211 static int __abortboot(int bootdelay)
212 {
213 int abort = 0;
214 unsigned long ts;
215
216 #ifdef CONFIG_MENUPROMPT
217 printf(CONFIG_MENUPROMPT);
218 #else
219 printf("Hit any key to stop autoboot: %2d ", bootdelay);
220 #endif
221
222 /*
223 * Check if key already pressed
224 */
225 if (tstc()) { /* we got a key press */
226 (void) getc(); /* consume input */
227 puts("\b\b\b 0");
228 abort = 1; /* don't auto boot */
229 }
230
231 while ((bootdelay > 0) && (!abort)) {
232 --bootdelay;
233 /* delay 1000 ms */
234 ts = get_timer(0);
235 do {
236 if (tstc()) { /* we got a key press */
237 abort = 1; /* don't auto boot */
238 bootdelay = 0; /* no more delay */
239 # ifdef CONFIG_MENUKEY
240 menukey = getc();
241 # else
242 (void) getc(); /* consume input */
243 # endif
244 break;
245 }
246 udelay(10000);
247 } while (!abort && get_timer(ts) < 1000);
248
249 printf("\b\b\b%2d ", bootdelay);
250 }
251
252 putc('\n');
253
254 return abort;
255 }
256 # endif /* CONFIG_AUTOBOOT_KEYED */
257
abortboot(int bootdelay)258 static int abortboot(int bootdelay)
259 {
260 int abort = 0;
261
262 if (bootdelay >= 0)
263 abort = __abortboot(bootdelay);
264
265 #ifdef CONFIG_SILENT_CONSOLE
266 if (abort)
267 gd->flags &= ~GD_FLG_SILENT;
268 #endif
269
270 return abort;
271 }
272
process_fdt_options(const void * blob)273 static void process_fdt_options(const void *blob)
274 {
275 #if defined(CONFIG_OF_CONTROL) && defined(CONFIG_SYS_TEXT_BASE)
276 ulong addr;
277
278 /* Add an env variable to point to a kernel payload, if available */
279 addr = fdtdec_get_config_int(gd->fdt_blob, "kernel-offset", 0);
280 if (addr)
281 env_set_addr("kernaddr", (void *)(CONFIG_SYS_TEXT_BASE + addr));
282
283 /* Add an env variable to point to a root disk, if available */
284 addr = fdtdec_get_config_int(gd->fdt_blob, "rootdisk-offset", 0);
285 if (addr)
286 env_set_addr("rootaddr", (void *)(CONFIG_SYS_TEXT_BASE + addr));
287 #endif /* CONFIG_OF_CONTROL && CONFIG_SYS_TEXT_BASE */
288 }
289
bootdelay_process(void)290 const char *bootdelay_process(void)
291 {
292 char *s;
293 int bootdelay;
294
295 bootcount_inc();
296
297 s = env_get("bootdelay");
298 bootdelay = s ? (int)simple_strtol(s, NULL, 10) : CONFIG_BOOTDELAY;
299
300 #ifdef CONFIG_OF_CONTROL
301 bootdelay = fdtdec_get_config_int(gd->fdt_blob, "bootdelay",
302 bootdelay);
303 #endif
304
305 debug("### main_loop entered: bootdelay=%d\n\n", bootdelay);
306
307 #if defined(CONFIG_MENU_SHOW)
308 bootdelay = menu_show(bootdelay);
309 #endif
310 bootretry_init_cmd_timeout();
311
312 #ifdef CONFIG_POST
313 if (gd->flags & GD_FLG_POSTFAIL) {
314 s = env_get("failbootcmd");
315 } else
316 #endif /* CONFIG_POST */
317 if (bootcount_error())
318 s = env_get("altbootcmd");
319 else
320 s = env_get("bootcmd");
321
322 process_fdt_options(gd->fdt_blob);
323 stored_bootdelay = bootdelay;
324
325 return s;
326 }
327
autoboot_command(const char * s)328 void autoboot_command(const char *s)
329 {
330 debug("### main_loop: bootcmd=\"%s\"\n", s ? s : "<UNDEFINED>");
331
332 if (stored_bootdelay != -1 && s && !abortboot(stored_bootdelay)) {
333 #if defined(CONFIG_AUTOBOOT_KEYED) && !defined(CONFIG_AUTOBOOT_KEYED_CTRLC)
334 int prev = disable_ctrlc(1); /* disable Control C checking */
335 #endif
336
337 run_command_list(s, -1, 0);
338
339 #if defined(CONFIG_AUTOBOOT_KEYED) && !defined(CONFIG_AUTOBOOT_KEYED_CTRLC)
340 disable_ctrlc(prev); /* restore Control C checking */
341 #endif
342 }
343
344 #ifdef CONFIG_MENUKEY
345 if (menukey == CONFIG_MENUKEY) {
346 s = env_get("menucmd");
347 if (s)
348 run_command_list(s, -1, 0);
349 }
350 #endif /* CONFIG_MENUKEY */
351 }
352