xref: /rk3399_rockchip-uboot/common/android_bootloader.c (revision a14c50f0dfd10c2337745490166090f9f1cd6710)
1 /*
2  * Copyright (C) 2016 The Android Open Source Project
3  *
4  * SPDX-License-Identifier: BSD-2-Clause
5  */
6 
7 #include <android_bootloader.h>
8 #include <android_bootloader_message.h>
9 #include <android_avb/avb_slot_verify.h>
10 #include <android_avb/avb_ops_user.h>
11 #include <android_avb/rk_avb_ops_user.h>
12 
13 #include <cli.h>
14 #include <common.h>
15 #include <malloc.h>
16 #include <fs.h>
17 #include <boot_rkimg.h>
18 #include <attestation_key.h>
19 #include <optee_include/OpteeClientInterface.h>
20 
21 #define ANDROID_PARTITION_BOOT "boot"
22 #define ANDROID_PARTITION_MISC "misc"
23 #define ANDROID_PARTITION_OEM  "oem"
24 #define ANDROID_PARTITION_RECOVERY  "recovery"
25 #define ANDROID_PARTITION_SYSTEM "system"
26 
27 #define ANDROID_ARG_SLOT_SUFFIX "androidboot.slot_suffix="
28 #define ANDROID_ARG_ROOT "root="
29 #define ANDROID_ARG_SERIALNO "androidboot.serialno="
30 #ifdef CONFIG_ROCKCHIP_RESOURCE_IMAGE
31 #define ANDROID_ARG_FDT_FILENAME "rk-kernel.dtb"
32 #define BOOTLOADER_MESSAGE_OFFSET_IN_MISC	(16 * 1024)
33 #define BOOTLOADER_MESSAGE_BLK_OFFSET	(BOOTLOADER_MESSAGE_OFFSET_IN_MISC >> 9)
34 #else
35 #define ANDROID_ARG_FDT_FILENAME "kernel.dtb"
36 #endif
37 #define OEM_UNLOCK_ARG_SIZE 30
38 
39 char *android_str_append(char *base_name, char *slot_suffix)
40 {
41 	char *part_name;
42 	size_t part_name_len;
43 
44 	part_name_len = strlen(base_name) + 1;
45 	if (slot_suffix)
46 		part_name_len += strlen(slot_suffix);
47 	part_name = malloc(part_name_len);
48 	if (!part_name)
49 		return NULL;
50 	strcpy(part_name, base_name);
51 	if (slot_suffix && (slot_suffix[0] != '\0'))
52 		strcat(part_name, slot_suffix);
53 
54 	return part_name;
55 }
56 
57 int android_bootloader_message_load(
58 	struct blk_desc *dev_desc,
59 	const disk_partition_t *part_info,
60 	struct android_bootloader_message *message)
61 {
62 	ulong message_blocks = sizeof(struct android_bootloader_message) /
63 	    part_info->blksz;
64 	if (message_blocks > part_info->size) {
65 		printf("misc partition too small.\n");
66 		return -1;
67 	}
68 
69 #ifdef CONFIG_RKIMG_BOOTLOADER
70 	if (blk_dread(dev_desc, part_info->start + BOOTLOADER_MESSAGE_BLK_OFFSET,
71 	     message_blocks, message) !=
72 #else
73 	if (blk_dread(dev_desc, part_info->start, message_blocks, message) !=
74 #endif
75 	    message_blocks) {
76 		printf("Could not read from misc partition\n");
77 		return -1;
78 	}
79 	debug("ANDROID: Loaded BCB, %lu blocks.\n", message_blocks);
80 	return 0;
81 }
82 
83 static int android_bootloader_message_write(
84 	struct blk_desc *dev_desc,
85 	const disk_partition_t *part_info,
86 	struct android_bootloader_message *message)
87 {
88 	ulong message_blocks = sizeof(struct android_bootloader_message) /
89 	    part_info->blksz;
90 	if (message_blocks > part_info->size) {
91 		printf("misc partition too small.\n");
92 		return -1;
93 	}
94 
95 	if (blk_dwrite(dev_desc, part_info->start, message_blocks, message) !=
96 	    message_blocks) {
97 		printf("Could not write to misc partition\n");
98 		return -1;
99 	}
100 	debug("ANDROID: Wrote new BCB, %lu blocks.\n", message_blocks);
101 	return 0;
102 }
103 
104 static enum android_boot_mode android_bootloader_load_and_clear_mode(
105 	struct blk_desc *dev_desc,
106 	const disk_partition_t *misc_part_info)
107 {
108 	struct android_bootloader_message bcb;
109 
110 #ifdef CONFIG_FASTBOOT
111 	char *bootloader_str;
112 
113 	/* Check for message from bootloader stored in RAM from a previous boot.
114 	 */
115 	bootloader_str = (char *)CONFIG_FASTBOOT_BUF_ADDR;
116 	if (!strcmp("reboot-bootloader", bootloader_str)) {
117 		bootloader_str[0] = '\0';
118 		return ANDROID_BOOT_MODE_BOOTLOADER;
119 	}
120 #endif
121 
122 	/* Check and update the BCB message if needed. */
123 	if (android_bootloader_message_load(dev_desc, misc_part_info, &bcb) <
124 	    0) {
125 		printf("WARNING: Unable to load the BCB.\n");
126 		return ANDROID_BOOT_MODE_NORMAL;
127 	}
128 
129 	if (!strcmp("bootonce-bootloader", bcb.command)) {
130 		/* Erase the message in the BCB since this value should be used
131 		 * only once.
132 		 */
133 		memset(bcb.command, 0, sizeof(bcb.command));
134 		android_bootloader_message_write(dev_desc, misc_part_info,
135 						 &bcb);
136 		return ANDROID_BOOT_MODE_BOOTLOADER;
137 	}
138 
139 	if (!strcmp("boot-recovery", bcb.command))
140 		return ANDROID_BOOT_MODE_RECOVERY;
141 
142 	return ANDROID_BOOT_MODE_NORMAL;
143 }
144 
145 /**
146  * Return the reboot reason string for the passed boot mode.
147  *
148  * @param mode	The Android Boot mode.
149  * @return a pointer to the reboot reason string for mode.
150  */
151 static const char *android_boot_mode_str(enum android_boot_mode mode)
152 {
153 	switch (mode) {
154 	case ANDROID_BOOT_MODE_NORMAL:
155 		return "(none)";
156 	case ANDROID_BOOT_MODE_RECOVERY:
157 		return "recovery";
158 	case ANDROID_BOOT_MODE_BOOTLOADER:
159 		return "bootloader";
160 	}
161 	return NULL;
162 }
163 
164 static int android_part_get_info_by_name_suffix(struct blk_desc *dev_desc,
165 						const char *base_name,
166 						const char *slot_suffix,
167 						disk_partition_t *part_info)
168 {
169 	char *part_name;
170 	int part_num;
171 	size_t part_name_len;
172 
173 	part_name_len = strlen(base_name) + 1;
174 	if (slot_suffix)
175 		part_name_len += strlen(slot_suffix);
176 	part_name = malloc(part_name_len);
177 	if (!part_name)
178 		return -1;
179 	strcpy(part_name, base_name);
180 	if (slot_suffix && (slot_suffix[0] != '\0'))
181 		strcat(part_name, slot_suffix);
182 
183 	part_num = part_get_info_by_name(dev_desc, part_name, part_info);
184 	if (part_num < 0) {
185 		debug("ANDROID: Could not find partition \"%s\"\n", part_name);
186 		part_num = -1;
187 	}
188 
189 	free(part_name);
190 	return part_num;
191 }
192 
193 static int android_bootloader_boot_bootloader(void)
194 {
195 	const char *fastboot_cmd = env_get("fastbootcmd");
196 
197 	if (fastboot_cmd)
198 		return run_command(fastboot_cmd, CMD_FLAG_ENV);
199 	return -1;
200 }
201 
202 #ifdef CONFIG_SUPPORT_OEM_DTB
203 static int android_bootloader_get_fdt(const char *part_name,
204 		const char *load_file_name)
205 {
206 	const char *dev_iface = "mmc";
207 	struct blk_desc *dev_desc;
208 	disk_partition_t boot_part_info;
209 	char *fdt_addr = NULL;
210 	char slot_suffix[5] = {0};
211 	char dev_part[3] = {0};
212 	loff_t bytes = 0;
213 	loff_t pos = 0;
214 	loff_t len_read;
215 	unsigned long addr = 0;
216 	int part_num = -1;
217 	int dev_num = 0;
218 	int ret;
219 
220 	dev_desc = blk_get_dev(dev_iface, dev_num);
221 	if (!dev_desc) {
222 		printf("Could not find %s %d\n", dev_iface, dev_num);
223 		return -1;
224 	}
225 
226 	memset(&boot_part_info, 0, sizeof(boot_part_info));
227 
228 #ifdef CONFIG_RK_AVB_LIBAVB_USER
229 	if (rk_avb_get_current_slot(slot_suffix)) {
230 		printf("ANDROID: Get Current Slot error.\n");
231 		return -1;
232 	}
233 
234 	part_num = android_part_get_info_by_name_suffix(dev_desc,
235 					     part_name,
236 					     slot_suffix, &boot_part_info);
237 #else
238 	part_num = part_get_info_by_name(dev_desc, part_name, &boot_part_info);
239 	if (part_num < 0) {
240 		printf("ANDROID: Could not find partition \"%s\"\n", part_name);
241 		return -1;
242 	}
243 #endif
244 
245 	snprintf(dev_part, ARRAY_SIZE(dev_part), ":%x", part_num);
246 	if (fs_set_blk_dev(dev_iface, dev_part, FS_TYPE_EXT))
247 		return -1;
248 
249 	fdt_addr = env_get("fdt_addr_r");
250 	if (!fdt_addr) {
251 		printf("ANDROID: No Found FDT Load Address.\n");
252 		return -1;
253 	}
254 	addr = simple_strtoul(fdt_addr, NULL, 16);
255 
256 	ret = fs_read(load_file_name, addr, pos, bytes, &len_read);
257 	if (ret < 0)
258 		return -1;
259 
260 	return 0;
261 }
262 #endif
263 
264 int android_bootloader_boot_kernel(unsigned long kernel_address)
265 {
266 	char kernel_addr_str[12];
267 	char *fdt_addr = env_get("fdt_addr");
268 	char *bootm_args[] = {
269 		"bootm", kernel_addr_str, kernel_addr_str, fdt_addr, NULL };
270 
271 	sprintf(kernel_addr_str, "0x%lx", kernel_address);
272 
273 	printf("Booting kernel at %s with fdt at %s...\n\n\n",
274 	       kernel_addr_str, fdt_addr);
275 	do_bootm(NULL, 0, 4, bootm_args);
276 
277 	return -1;
278 }
279 
280 static char *strjoin(const char **chunks, char separator)
281 {
282 	int len, joined_len = 0;
283 	char *ret, *current;
284 	const char **p;
285 
286 	for (p = chunks; *p; p++)
287 		joined_len += strlen(*p) + 1;
288 
289 	if (!joined_len) {
290 		ret = malloc(1);
291 		if (ret)
292 			ret[0] = '\0';
293 		return ret;
294 	}
295 
296 	ret = malloc(joined_len);
297 	current = ret;
298 	if (!ret)
299 		return ret;
300 
301 	for (p = chunks; *p; p++) {
302 		len = strlen(*p);
303 		memcpy(current, *p, len);
304 		current += len;
305 		*current = separator;
306 		current++;
307 	}
308 	/* Replace the last separator by a \0. */
309 	current[-1] = '\0';
310 	return ret;
311 }
312 
313 /** android_assemble_cmdline - Assemble the command line to pass to the kernel
314  * @return a newly allocated string
315  */
316 char *android_assemble_cmdline(const char *slot_suffix,
317 				      const char *extra_args)
318 {
319 	const char *cmdline_chunks[16];
320 	const char **current_chunk = cmdline_chunks;
321 	char *env_cmdline, *cmdline, *rootdev_input, *serialno;
322 	char *allocated_suffix = NULL;
323 	char *allocated_serialno = NULL;
324 	char *allocated_rootdev = NULL;
325 	unsigned long rootdev_len;
326 
327 	env_cmdline = env_get("bootargs");
328 	if (env_cmdline)
329 		*(current_chunk++) = env_cmdline;
330 
331 	/* The |slot_suffix| needs to be passed to the kernel to know what
332 	 * slot to boot from.
333 	 */
334 	if (slot_suffix) {
335 		allocated_suffix = malloc(strlen(ANDROID_ARG_SLOT_SUFFIX) +
336 					  strlen(slot_suffix) + 1);
337 		memset(allocated_suffix, 0, strlen(ANDROID_ARG_SLOT_SUFFIX)
338 		       + strlen(slot_suffix) + 1);
339 		strcpy(allocated_suffix, ANDROID_ARG_SLOT_SUFFIX);
340 		strcat(allocated_suffix, slot_suffix);
341 		*(current_chunk++) = allocated_suffix;
342 	}
343 
344 	serialno = env_get("serial#");
345 	if (serialno) {
346 		allocated_serialno = malloc(strlen(ANDROID_ARG_SERIALNO) +
347 					  strlen(serialno) + 1);
348 		memset(allocated_serialno, 0, strlen(ANDROID_ARG_SERIALNO) +
349 				strlen(serialno) + 1);
350 		strcpy(allocated_serialno, ANDROID_ARG_SERIALNO);
351 		strcat(allocated_serialno, serialno);
352 		*(current_chunk++) = allocated_serialno;
353 	}
354 
355 	rootdev_input = env_get("android_rootdev");
356 	if (rootdev_input) {
357 		rootdev_len = strlen(ANDROID_ARG_ROOT) + CONFIG_SYS_CBSIZE + 1;
358 		allocated_rootdev = malloc(rootdev_len);
359 		strcpy(allocated_rootdev, ANDROID_ARG_ROOT);
360 		cli_simple_process_macros(rootdev_input,
361 					  allocated_rootdev +
362 					  strlen(ANDROID_ARG_ROOT));
363 		/* Make sure that the string is null-terminated since the
364 		 * previous could not copy to the end of the input string if it
365 		 * is too big.
366 		 */
367 		allocated_rootdev[rootdev_len - 1] = '\0';
368 		*(current_chunk++) = allocated_rootdev;
369 	}
370 
371 	if (extra_args)
372 		*(current_chunk++) = extra_args;
373 
374 	*(current_chunk++) = NULL;
375 	cmdline = strjoin(cmdline_chunks, ' ');
376 	free(allocated_suffix);
377 	free(allocated_rootdev);
378 	return cmdline;
379 }
380 
381 #ifdef CONFIG_ANDROID_AVB
382 static void slot_set_unbootable(AvbABSlotData* slot)
383 {
384 	slot->priority = 0;
385 	slot->tries_remaining = 0;
386 	slot->successful_boot = 0;
387 }
388 
389 static AvbSlotVerifyResult android_slot_verify(char *boot_partname,
390 			       unsigned long load_address,
391 			       char *slot_suffix)
392 {
393 	const char *requested_partitions[1] = {NULL};
394 	uint8_t unlocked = true;
395 	AvbOps *ops;
396 	AvbSlotVerifyFlags flags;
397 	AvbSlotVerifyData *slot_data[1] = {NULL};
398 	AvbSlotVerifyResult verify_result;
399 	AvbABData ab_data, ab_data_orig;
400 	size_t slot_index_to_boot = 0;
401 
402 	requested_partitions[0] = boot_partname;
403 	ops = avb_ops_user_new();
404 	if (ops == NULL) {
405 		printf("avb_ops_user_new() failed!\n");
406 		return AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
407 	}
408 
409 	if (ops->read_is_device_unlocked(ops, (bool *)&unlocked) != AVB_IO_RESULT_OK)
410 		printf("Error determining whether device is unlocked.\n");
411 
412 	printf("read_is_device_unlocked() ops returned that device is %s\n",
413 	       (unlocked & LOCK_MASK)? "UNLOCKED" : "LOCKED");
414 
415 	flags = AVB_SLOT_VERIFY_FLAGS_NONE;
416 	if (unlocked & LOCK_MASK)
417 		flags |= AVB_SLOT_VERIFY_FLAGS_ALLOW_VERIFICATION_ERROR;
418 
419 	if(load_metadata(ops->ab_ops, &ab_data, &ab_data_orig)) {
420 		printf("Can not load metadata\n");
421 		return AVB_SLOT_VERIFY_RESULT_ERROR_IO;
422 	}
423 
424 	if (strncmp(slot_suffix, "_a", 2))
425 		slot_index_to_boot = 0;
426 	else if(strncmp(slot_suffix, "_b", 2))
427 		slot_index_to_boot = 1;
428 	else
429 		slot_index_to_boot = 0;
430 
431 	verify_result =
432 	avb_slot_verify(ops,
433 			requested_partitions,
434 			slot_suffix,
435 			flags,
436 			AVB_HASHTREE_ERROR_MODE_RESTART_AND_INVALIDATE,
437 			&slot_data[0]);
438 
439 	if (verify_result != AVB_SLOT_VERIFY_RESULT_OK) {
440 		slot_set_unbootable(&ab_data.slots[slot_index_to_boot]);
441 		goto out;
442 	}
443 
444 	memcpy((uint8_t*)load_address,
445 	       slot_data[0]->loaded_partitions->data,
446 	       slot_data[0]->loaded_partitions->data_size);
447 	env_set("bootargs", slot_data[0]->cmdline);
448 
449 	/* ... and decrement tries remaining, if applicable. */
450 	if (!ab_data.slots[slot_index_to_boot].successful_boot &&
451 		ab_data.slots[slot_index_to_boot].tries_remaining > 0) {
452 		ab_data.slots[slot_index_to_boot].tries_remaining -= 1;
453 	}
454 out:
455 	if (save_metadata_if_changed(ops->ab_ops, &ab_data, &ab_data_orig)) {
456 		printf("Can not save metadata\n");
457 		verify_result = AVB_SLOT_VERIFY_RESULT_ERROR_IO;
458 	}
459 
460 	if (slot_data[0] != NULL)
461 		avb_slot_verify_data_free(slot_data[0]);
462 
463 	return verify_result;
464 }
465 #endif
466 
467 int android_bootloader_boot_flow(struct blk_desc *dev_desc,
468 				 unsigned long load_address)
469 {
470 	enum android_boot_mode mode;
471 	disk_partition_t misc_part_info;
472 	int part_num;
473 	int ret;
474 	char *command_line;
475 	char slot_suffix[3] = {0};
476 	const char *mode_cmdline = NULL;
477 	char *boot_partname = ANDROID_PARTITION_BOOT;
478 	ulong fdt_addr;
479 
480 	/*
481 	 * 1. Load MISC partition and determine the boot mode
482 	 *   clear its value for the next boot if needed.
483 	 */
484 	part_num = part_get_info_by_name(dev_desc, ANDROID_PARTITION_MISC,
485 					 &misc_part_info);
486 	if (part_num < 0)
487 		printf("%s Could not find misc partition\n", __func__);
488 
489 #ifdef CONFIG_OPTEE_CLIENT
490 	/* load attestation key from misc partition. */
491 	load_attestation_key(dev_desc, &misc_part_info);
492 #endif
493 
494 	mode = android_bootloader_load_and_clear_mode(dev_desc, &misc_part_info);
495 #ifdef CONFIG_RKIMG_BOOTLOADER
496 	if (mode == ANDROID_BOOT_MODE_NORMAL) {
497 		if (rockchip_get_boot_mode() == BOOT_MODE_RECOVERY)
498 			mode = ANDROID_BOOT_MODE_RECOVERY;
499 	}
500 #endif
501 	printf("ANDROID: reboot reason: \"%s\"\n", android_boot_mode_str(mode));
502 
503 	switch (mode) {
504 	case ANDROID_BOOT_MODE_NORMAL:
505 		/* In normal mode, we load the kernel from "boot" but append
506 		 * "skip_initramfs" to the cmdline to make it ignore the
507 		 * recovery initramfs in the boot partition.
508 		 */
509 #ifdef CONFIG_ANDROID_AB
510 		mode_cmdline = "skip_initramfs";
511 #endif
512 		break;
513 	case ANDROID_BOOT_MODE_RECOVERY:
514 		/* In recovery mode we still boot the kernel from "boot" but
515 		 * don't skip the initramfs so it boots to recovery.
516 		 */
517 #ifndef CONFIG_ANDROID_AB
518 		boot_partname = ANDROID_PARTITION_RECOVERY;
519 #endif
520 		break;
521 	case ANDROID_BOOT_MODE_BOOTLOADER:
522 		/* Bootloader mode enters fastboot. If this operation fails we
523 		 * simply return since we can't recover from this situation by
524 		 * switching to another slot.
525 		 */
526 		return android_bootloader_boot_bootloader();
527 	}
528 
529 #ifdef CONFIG_ANDROID_AB
530 	/*TODO: get from pre-loader or misc partition*/
531 	if (rk_avb_get_current_slot(slot_suffix))
532 		return -1;
533 
534 	if (slot_suffix[0] != '_') {
535 		printf("There is no bootable slot!\n");
536 		return -1;
537 	}
538 #endif
539 
540 #ifdef CONFIG_ANDROID_AVB
541 	if (android_slot_verify(boot_partname, load_address, slot_suffix))
542 		return -1;
543 #else
544 	/*
545 	 * 2. Load the boot/recovery from the desired "boot" partition.
546 	 * Determine if this is an AOSP image.
547 	 */
548 	disk_partition_t boot_part_info;
549 	part_num =
550 	    android_part_get_info_by_name_suffix(dev_desc,
551 						 boot_partname,
552 						 slot_suffix, &boot_part_info);
553 	if (part_num < 0) {
554 		printf("%s Could not found bootable partition %s\n", __func__,
555 		       boot_partname);
556 		return -1;
557 	}
558 	debug("ANDROID: Loading kernel from \"%s\", partition %d.\n",
559 	      boot_part_info.name, part_num);
560 
561 	ret = android_image_load(dev_desc, &boot_part_info, load_address,
562 				 -1UL);
563 	if (ret < 0) {
564 		printf("%s %s part load fail\n", __func__, boot_part_info.name);
565 		return ret;
566 	}
567 #endif
568 
569 	/* Set Android root variables. */
570 	env_set_ulong("android_root_devnum", dev_desc->devnum);
571 	env_set("android_slotsufix", slot_suffix);
572 
573 #ifdef CONFIG_OPTEE_CLIENT
574 	/* read oem unlock status and attach to bootargs */
575 	uint8_t unlock = 0;
576 	TEEC_Result result;
577 	char oem_unlock[OEM_UNLOCK_ARG_SIZE] = {0};
578 	result = trusty_read_oem_unlock(&unlock);
579 	if (result) {
580 		printf("read oem unlock status with error : 0x%x\n", result);
581 	} else {
582 		snprintf(oem_unlock, OEM_UNLOCK_ARG_SIZE, "androidboot.oem_unlocked=%d", unlock);
583 		env_update("bootargs", oem_unlock);
584 	}
585 #endif
586 
587 	/* Assemble the command line */
588 	command_line = android_assemble_cmdline(slot_suffix, mode_cmdline);
589 	env_update("bootargs", command_line);
590 
591 	debug("ANDROID: bootargs: \"%s\"\n", command_line);
592 
593 #ifdef CONFIG_SUPPORT_OEM_DTB
594 	if (android_bootloader_get_fdt(ANDROID_PARTITION_OEM,
595 				       ANDROID_ARG_FDT_FILENAME)) {
596 		printf("Can not get the fdt data from oem!\n");
597 	}
598 #else
599 	ret = android_image_get_fdt((void *)load_address, &fdt_addr);
600 	if (!ret)
601 		env_set_hex("fdt_addr", fdt_addr);
602 #endif
603 	android_bootloader_boot_kernel(load_address);
604 
605 	/* TODO: If the kernel doesn't boot mark the selected slot as bad. */
606 	return -1;
607 }
608 
609 int android_avb_boot_flow(char *slot_suffix, unsigned long kernel_address)
610 {
611 	const char *dev_iface = "mmc";
612 	int dev_num = 0;
613 	struct blk_desc *dev_desc;
614 	disk_partition_t boot_part_info;
615 	int ret;
616 	dev_desc = blk_get_dev(dev_iface, dev_num);
617 	if (!dev_desc) {
618 		printf("Could not find %s %d\n", dev_iface, dev_num);
619 		return -1;
620 	}
621 	/* Load the kernel from the desired "boot" partition. */
622 	android_part_get_info_by_name_suffix(dev_desc,
623 					     ANDROID_PARTITION_BOOT,
624 					     slot_suffix, &boot_part_info);
625 	ret = android_image_load(dev_desc, &boot_part_info, kernel_address,
626 				 -1UL);
627 	if (ret < 0)
628 		return ret;
629 	android_bootloader_boot_kernel(kernel_address);
630 
631 	/* TODO: If the kernel doesn't boot mark the selected slot as bad. */
632 	return -1;
633 }
634 
635 int android_boot_flow(unsigned long kernel_address)
636 {
637 	const char *dev_iface = "mmc";
638 	int dev_num = 0;
639 	struct blk_desc *dev_desc;
640 	disk_partition_t boot_part_info;
641 	int ret;
642 	dev_desc = blk_get_dev(dev_iface, dev_num);
643 	if (!dev_desc) {
644 		printf("Could not find %s %d\n", dev_iface, dev_num);
645 		return -1;
646 	}
647 	/* Load the kernel from the desired "boot" partition. */
648 	part_get_info_by_name(dev_desc, ANDROID_PARTITION_BOOT, &boot_part_info);
649 	ret = android_image_load(dev_desc, &boot_part_info, kernel_address,
650 				 -1UL);
651 	if (ret < 0)
652 		return ret;
653 	android_bootloader_boot_kernel(kernel_address);
654 
655 	/* TODO: If the kernel doesn't boot mark the selected slot as bad. */
656 	return -1;
657 }
658