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review.trustedfirmware.org / mirror / mcuboot / 10ee648145adc508bd09cf1947fe0872d776833c / . / boot / bootutil / src / loader.c
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/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
/*
* Modifications are Copyright (c) 2019 Arm Limited.
*/
/**
* This file provides an interface to the boot loader. Functions defined in
* this file should only be called while the boot loader is running.
*/
#include <assert.h>
#include <stddef.h>
#include <stdbool.h>
#include <inttypes.h>
#include <stdlib.h>
#include <string.h>
#include <os/os_malloc.h>
#include "bootutil/bootutil.h"
#include "bootutil/image.h"
#include "bootutil_priv.h"
#include "bootutil/bootutil_log.h"
#ifdef MCUBOOT_ENC_IMAGES
#include "bootutil/enc_key.h"
#endif
#include "mcuboot_config/mcuboot_config.h"
MCUBOOT_LOG_MODULE_DECLARE(mcuboot);
static struct boot_loader_state boot_data;
#if (BOOT_IMAGE_NUMBER > 1)
#define IMAGES_ITER(x) for ((x) = 0; (x) < BOOT_IMAGE_NUMBER; ++(x))
#else
#define IMAGES_ITER(x)
#endif
/*
* This macro allows some control on the allocation of local variables.
* When running natively on a target, we don't want to allocated huge
* variables on the stack, so make them global instead. For the simulator
* we want to run as many threads as there are tests, and it's safer
* to just make those variables stack allocated.
*/
#if !defined(__BOOTSIM__)
#define TARGET_STATIC static
#else
#define TARGET_STATIC
#endif
#if defined(MCUBOOT_VALIDATE_PRIMARY_SLOT) && !defined(MCUBOOT_OVERWRITE_ONLY)
/*
* FIXME: this might have to be updated for threaded sim
*/
static int boot_status_fails = 0;
#define BOOT_STATUS_ASSERT(x) \
do { \
if (!(x)) { \
boot_status_fails++; \
} \
} while (0)
#else
#define BOOT_STATUS_ASSERT(x) ASSERT(x)
#endif
struct boot_status_table {
uint8_t bst_magic_primary_slot;
uint8_t bst_magic_scratch;
uint8_t bst_copy_done_primary_slot;
uint8_t bst_status_source;
};
/**
* This set of tables maps swap state contents to boot status location.
* When searching for a match, these tables must be iterated in order.
*/
static const struct boot_status_table boot_status_tables[] = {
{
/* | primary slot | scratch |
* ----------+--------------+--------------|
* magic | Good | Any |
* copy-done | Set | N/A |
* ----------+--------------+--------------'
* source: none |
* ----------------------------------------'
*/
.bst_magic_primary_slot = BOOT_MAGIC_GOOD,
.bst_magic_scratch = BOOT_MAGIC_NOTGOOD,
.bst_copy_done_primary_slot = BOOT_FLAG_SET,
.bst_status_source = BOOT_STATUS_SOURCE_NONE,
},
{
/* | primary slot | scratch |
* ----------+--------------+--------------|
* magic | Good | Any |
* copy-done | Unset | N/A |
* ----------+--------------+--------------'
* source: primary slot |
* ----------------------------------------'
*/
.bst_magic_primary_slot = BOOT_MAGIC_GOOD,
.bst_magic_scratch = BOOT_MAGIC_NOTGOOD,
.bst_copy_done_primary_slot = BOOT_FLAG_UNSET,
.bst_status_source = BOOT_STATUS_SOURCE_PRIMARY_SLOT,
},
{
/* | primary slot | scratch |
* ----------+--------------+--------------|
* magic | Any | Good |
* copy-done | Any | N/A |
* ----------+--------------+--------------'
* source: scratch |
* ----------------------------------------'
*/
.bst_magic_primary_slot = BOOT_MAGIC_ANY,
.bst_magic_scratch = BOOT_MAGIC_GOOD,
.bst_copy_done_primary_slot = BOOT_FLAG_ANY,
.bst_status_source = BOOT_STATUS_SOURCE_SCRATCH,
},
{
/* | primary slot | scratch |
* ----------+--------------+--------------|
* magic | Unset | Any |
* copy-done | Unset | N/A |
* ----------+--------------+--------------|
* source: varies |
* ----------------------------------------+--------------------------+
* This represents one of two cases: |
* o No swaps ever (no status to read, so no harm in checking). |
* o Mid-revert; status in primary slot. |
* -------------------------------------------------------------------'
*/
.bst_magic_primary_slot = BOOT_MAGIC_UNSET,
.bst_magic_scratch = BOOT_MAGIC_ANY,
.bst_copy_done_primary_slot = BOOT_FLAG_UNSET,
.bst_status_source = BOOT_STATUS_SOURCE_PRIMARY_SLOT,
},
};
#define BOOT_STATUS_TABLES_COUNT \
(sizeof boot_status_tables / sizeof boot_status_tables[0])
#define BOOT_LOG_SWAP_STATE(area, state) \
BOOT_LOG_INF("%s: magic=%s, swap_type=0x%x, copy_done=0x%x, " \
"image_ok=0x%x", \
(area), \
((state)->magic == BOOT_MAGIC_GOOD ? "good" : \
(state)->magic == BOOT_MAGIC_UNSET ? "unset" : \
"bad"), \
(state)->swap_type, \
(state)->copy_done, \
(state)->image_ok)
/**
* Determines where in flash the most recent boot status is stored. The boot
* status is necessary for completing a swap that was interrupted by a boot
* loader reset.
*
* @return A BOOT_STATUS_SOURCE_[...] code indicating where status should
* be read from.
*/
static int
boot_status_source(struct boot_loader_state *state)
{
const struct boot_status_table *table;
struct boot_swap_state state_scratch;
struct boot_swap_state state_primary_slot;
int rc;
size_t i;
uint8_t source;
uint8_t image_index;
#if (BOOT_IMAGE_NUMBER == 1)
(void)state;
#endif
image_index = BOOT_CURR_IMG(state);
rc = boot_read_swap_state_by_id(FLASH_AREA_IMAGE_PRIMARY(image_index),
&state_primary_slot);
assert(rc == 0);
rc = boot_read_swap_state_by_id(FLASH_AREA_IMAGE_SCRATCH, &state_scratch);
assert(rc == 0);
BOOT_LOG_SWAP_STATE("Primary image", &state_primary_slot);
BOOT_LOG_SWAP_STATE("Scratch", &state_scratch);
for (i = 0; i < BOOT_STATUS_TABLES_COUNT; i++) {
table = &boot_status_tables[i];
if (boot_magic_compatible_check(table->bst_magic_primary_slot,
state_primary_slot.magic) &&
boot_magic_compatible_check(table->bst_magic_scratch,
state_scratch.magic) &&
(table->bst_copy_done_primary_slot == BOOT_FLAG_ANY ||
table->bst_copy_done_primary_slot == state_primary_slot.copy_done))
{
source = table->bst_status_source;
#if (BOOT_IMAGE_NUMBER > 1)
/* In case of multi-image boot it can happen that if boot status
* info is found on scratch area then it does not belong to the
* currently examined image.
*/
if (source == BOOT_STATUS_SOURCE_SCRATCH &&
state_scratch.image_num != BOOT_CURR_IMG(state)) {
source = BOOT_STATUS_SOURCE_NONE;
}
#endif
BOOT_LOG_INF("Boot source: %s",
source == BOOT_STATUS_SOURCE_NONE ? "none" :
source == BOOT_STATUS_SOURCE_SCRATCH ? "scratch" :
source == BOOT_STATUS_SOURCE_PRIMARY_SLOT ?
"primary slot" : "BUG; can't happen");
return source;
}
}
BOOT_LOG_INF("Boot source: none");
return BOOT_STATUS_SOURCE_NONE;
}
/*
* Compute the total size of the given image. Includes the size of
* the TLVs.
*/
#if !defined(MCUBOOT_OVERWRITE_ONLY) || defined(MCUBOOT_OVERWRITE_ONLY_FAST)
static int
boot_read_image_size(struct boot_loader_state *state, int slot,
struct image_header *hdr, uint32_t *size)
{
const struct flash_area *fap;
struct image_tlv_info info;
int area_id;
int rc;
#if (BOOT_IMAGE_NUMBER == 1)
(void)state;
#endif
area_id = flash_area_id_from_multi_image_slot(BOOT_CURR_IMG(state), slot);
rc = flash_area_open(area_id, &fap);
if (rc != 0) {
rc = BOOT_EFLASH;
goto done;
}
rc = flash_area_read(fap, hdr->ih_hdr_size + hdr->ih_img_size,
&info, sizeof(info));
if (rc != 0) {
rc = BOOT_EFLASH;
goto done;
}
if (info.it_magic != IMAGE_TLV_INFO_MAGIC) {
rc = BOOT_EBADIMAGE;
goto done;
}
*size = hdr->ih_hdr_size + hdr->ih_img_size + info.it_tlv_tot;
rc = 0;
done:
flash_area_close(fap);
return rc;
}
#endif /* !MCUBOOT_OVERWRITE_ONLY */
static int
boot_read_image_header(struct boot_loader_state *state, int slot,
struct image_header *out_hdr)
{
const struct flash_area *fap;
int area_id;
int rc;
#if (BOOT_IMAGE_NUMBER == 1)
(void)state;
#endif
area_id = flash_area_id_from_multi_image_slot(BOOT_CURR_IMG(state), slot);
rc = flash_area_open(area_id, &fap);
if (rc != 0) {
rc = BOOT_EFLASH;
goto done;
}
rc = flash_area_read(fap, 0, out_hdr, sizeof *out_hdr);
if (rc != 0) {
rc = BOOT_EFLASH;
goto done;
}
rc = 0;
done:
flash_area_close(fap);
return rc;
}
static int
boot_read_image_headers(struct boot_loader_state *state, bool require_all)
{
int rc;
int i;
for (i = 0; i < BOOT_NUM_SLOTS; i++) {
rc = boot_read_image_header(state, i, boot_img_hdr(state, i));
if (rc != 0) {
/* If `require_all` is set, fail on any single fail, otherwise
* if at least the first slot's header was read successfully,
* then the boot loader can attempt a boot.
*
* Failure to read any headers is a fatal error.
*/
if (i > 0 && !require_all) {
return 0;
} else {
return rc;
}
}
}
return 0;
}
static uint8_t
boot_write_sz(struct boot_loader_state *state)
{
uint8_t elem_sz;
uint8_t align;
/* Figure out what size to write update status update as. The size depends
* on what the minimum write size is for scratch area, active image slot.
* We need to use the bigger of those 2 values.
*/
elem_sz = flash_area_align(BOOT_IMG_AREA(state, BOOT_PRIMARY_SLOT));
align = flash_area_align(BOOT_SCRATCH_AREA(state));
if (align > elem_sz) {
elem_sz = align;
}
return elem_sz;
}
/*
* Slots are compatible when all sectors that store upto to size of the image
* round up to sector size, in both slot's are able to fit in the scratch
* area, and have sizes that are a multiple of each other (powers of two
* presumably!).
*/
static int
boot_slots_compatible(struct boot_loader_state *state)
{
size_t num_sectors_primary;
size_t num_sectors_secondary;
size_t sz0, sz1;
size_t primary_slot_sz, secondary_slot_sz;
size_t scratch_sz;
size_t i, j;
int8_t smaller;
num_sectors_primary = boot_img_num_sectors(state, BOOT_PRIMARY_SLOT);
num_sectors_secondary = boot_img_num_sectors(state, BOOT_SECONDARY_SLOT);
if ((num_sectors_primary > BOOT_MAX_IMG_SECTORS) ||
(num_sectors_secondary > BOOT_MAX_IMG_SECTORS)) {
BOOT_LOG_WRN("Cannot upgrade: more sectors than allowed");
return 0;
}
scratch_sz = boot_scratch_area_size(state);
/*
* The following loop scans all sectors in a linear fashion, assuring that
* for each possible sector in each slot, it is able to fit in the other
* slot's sector or sectors. Slot's should be compatible as long as any
* number of a slot's sectors are able to fit into another, which only
* excludes cases where sector sizes are not a multiple of each other.
*/
i = sz0 = primary_slot_sz = 0;
j = sz1 = secondary_slot_sz = 0;
smaller = 0;
while (i < num_sectors_primary || j < num_sectors_secondary) {
if (sz0 == sz1) {
sz0 += boot_img_sector_size(state, BOOT_PRIMARY_SLOT, i);
sz1 += boot_img_sector_size(state, BOOT_SECONDARY_SLOT, j);
i++;
j++;
} else if (sz0 < sz1) {
sz0 += boot_img_sector_size(state, BOOT_PRIMARY_SLOT, i);
/* Guarantee that multiple sectors of the secondary slot
* fit into the primary slot.
*/
if (smaller == 2) {
BOOT_LOG_WRN("Cannot upgrade: slots have non-compatible sectors");
return 0;
}
smaller = 1;
i++;
} else {
sz1 += boot_img_sector_size(state, BOOT_SECONDARY_SLOT, j);
/* Guarantee that multiple sectors of the primary slot
* fit into the secondary slot.
*/
if (smaller == 1) {
BOOT_LOG_WRN("Cannot upgrade: slots have non-compatible sectors");
return 0;
}
smaller = 2;
j++;
}
if (sz0 == sz1) {
primary_slot_sz += sz0;
secondary_slot_sz += sz1;
/* Scratch has to fit each swap operation to the size of the larger
* sector among the primary slot and the secondary slot.
*/
if (sz0 > scratch_sz || sz1 > scratch_sz) {
BOOT_LOG_WRN("Cannot upgrade: not all sectors fit inside scratch");
return 0;
}
smaller = sz0 = sz1 = 0;
}
}
if ((i != num_sectors_primary) ||
(j != num_sectors_secondary) ||
(primary_slot_sz != secondary_slot_sz)) {
BOOT_LOG_WRN("Cannot upgrade: slots are not compatible");
return 0;
}
return 1;
}
#ifndef MCUBOOT_USE_FLASH_AREA_GET_SECTORS
static int
boot_initialize_area(struct boot_loader_state *state, int flash_area)
{
int num_sectors = BOOT_MAX_IMG_SECTORS;
int rc;
if (flash_area == FLASH_AREA_IMAGE_PRIMARY(BOOT_CURR_IMG(state))) {
rc = flash_area_to_sectors(flash_area, &num_sectors,
BOOT_IMG(state, BOOT_PRIMARY_SLOT).sectors);
BOOT_IMG(state, BOOT_PRIMARY_SLOT).num_sectors = (size_t)num_sectors;
} else if (flash_area == FLASH_AREA_IMAGE_SECONDARY(BOOT_CURR_IMG(state))) {
rc = flash_area_to_sectors(flash_area, &num_sectors,
BOOT_IMG(state, BOOT_SECONDARY_SLOT).sectors);
BOOT_IMG(state, BOOT_SECONDARY_SLOT).num_sectors = (size_t)num_sectors;
} else if (flash_area == FLASH_AREA_IMAGE_SCRATCH) {
rc = flash_area_to_sectors(flash_area, &num_sectors,
state->scratch.sectors);
state->scratch.num_sectors = (size_t)num_sectors;
} else {
return BOOT_EFLASH;
}
return rc;
}
#else /* defined(MCUBOOT_USE_FLASH_AREA_GET_SECTORS) */
static int
boot_initialize_area(struct boot_loader_state *state, int flash_area)
{
uint32_t num_sectors;
struct flash_sector *out_sectors;
size_t *out_num_sectors;
int rc;
num_sectors = BOOT_MAX_IMG_SECTORS;
if (flash_area == FLASH_AREA_IMAGE_PRIMARY(BOOT_CURR_IMG(state))) {
out_sectors = BOOT_IMG(state, BOOT_PRIMARY_SLOT).sectors;
out_num_sectors = &BOOT_IMG(state, BOOT_PRIMARY_SLOT).num_sectors;
} else if (flash_area == FLASH_AREA_IMAGE_SECONDARY(BOOT_CURR_IMG(state))) {
out_sectors = BOOT_IMG(state, BOOT_SECONDARY_SLOT).sectors;
out_num_sectors = &BOOT_IMG(state, BOOT_SECONDARY_SLOT).num_sectors;
} else if (flash_area == FLASH_AREA_IMAGE_SCRATCH) {
out_sectors = state->scratch.sectors;
out_num_sectors = &state->scratch.num_sectors;
} else {
return BOOT_EFLASH;
}
rc = flash_area_get_sectors(flash_area, &num_sectors, out_sectors);
if (rc != 0) {
return rc;
}
*out_num_sectors = num_sectors;
return 0;
}
#endif /* !defined(MCUBOOT_USE_FLASH_AREA_GET_SECTORS) */
/**
* Determines the sector layout of both image slots and the scratch area.
* This information is necessary for calculating the number of bytes to erase
* and copy during an image swap. The information collected during this
* function is used to populate the state.
*/
static int
boot_read_sectors(struct boot_loader_state *state)
{
uint8_t image_index;
int rc;
image_index = BOOT_CURR_IMG(state);
rc = boot_initialize_area(state, FLASH_AREA_IMAGE_PRIMARY(image_index));
if (rc != 0) {
return BOOT_EFLASH;
}
rc = boot_initialize_area(state, FLASH_AREA_IMAGE_SECONDARY(image_index));
if (rc != 0) {
return BOOT_EFLASH;
}
rc = boot_initialize_area(state, FLASH_AREA_IMAGE_SCRATCH);
if (rc != 0) {
return BOOT_EFLASH;
}
BOOT_WRITE_SZ(state) = boot_write_sz(state);
return 0;
}
static uint32_t
boot_status_internal_off(int idx, int state, int elem_sz)
{
int idx_sz;
idx_sz = elem_sz * BOOT_STATUS_STATE_COUNT;
return (idx - BOOT_STATUS_IDX_0) * idx_sz +
(state - BOOT_STATUS_STATE_0) * elem_sz;
}
/**
* Reads the status of a partially-completed swap, if any. This is necessary
* to recover in case the boot lodaer was reset in the middle of a swap
* operation.
*/
static int
boot_read_status_bytes(const struct flash_area *fap,
struct boot_loader_state *state, struct boot_status *bs)
{
uint32_t off;
uint8_t status;
int max_entries;
int found;
int found_idx;
int invalid;
int rc;
int i;
off = boot_status_off(fap);
max_entries = boot_status_entries(BOOT_CURR_IMG(state), fap);
found = 0;
found_idx = 0;
invalid = 0;
for (i = 0; i < max_entries; i++) {
rc = flash_area_read_is_empty(fap, off + i * BOOT_WRITE_SZ(state),
&status, 1);
if (rc < 0) {
return BOOT_EFLASH;
}
if (rc == 1) {
if (found && !found_idx) {
found_idx = i;
}
} else if (!found) {
found = 1;
} else if (found_idx) {
invalid = 1;
break;
}
}
if (invalid) {
/* This means there was an error writing status on the last
* swap. Tell user and move on to validation!
*/
BOOT_LOG_ERR("Detected inconsistent status!");
#if !defined(MCUBOOT_VALIDATE_PRIMARY_SLOT)
/* With validation of the primary slot disabled, there is no way
* to be sure the swapped primary slot is OK, so abort!
*/
assert(0);
#endif
}
if (found) {
if (!found_idx) {
found_idx = i;
}
found_idx--;
bs->idx = (found_idx / BOOT_STATUS_STATE_COUNT) + 1;
bs->state = (found_idx % BOOT_STATUS_STATE_COUNT) + 1;
}
return 0;
}
/**
* Reads the boot status from the flash. The boot status contains
* the current state of an interrupted image copy operation. If the boot
* status is not present, or it indicates that previous copy finished,
* there is no operation in progress.
*/
static int
boot_read_status(struct boot_loader_state *state, struct boot_status *bs)
{
const struct flash_area *fap;
uint32_t off;
uint8_t swap_info;
int status_loc;
int area_id;
int rc;
memset(bs, 0, sizeof *bs);
bs->idx = BOOT_STATUS_IDX_0;
bs->state = BOOT_STATUS_STATE_0;
bs->swap_type = BOOT_SWAP_TYPE_NONE;
#ifdef MCUBOOT_OVERWRITE_ONLY
/* Overwrite-only doesn't make use of the swap status area. */
return 0;
#endif
status_loc = boot_status_source(state);
switch (status_loc) {
case BOOT_STATUS_SOURCE_NONE:
return 0;
case BOOT_STATUS_SOURCE_SCRATCH:
area_id = FLASH_AREA_IMAGE_SCRATCH;
break;
case BOOT_STATUS_SOURCE_PRIMARY_SLOT:
area_id = FLASH_AREA_IMAGE_PRIMARY(BOOT_CURR_IMG(state));
break;
default:
assert(0);
return BOOT_EBADARGS;
}
rc = flash_area_open(area_id, &fap);
if (rc != 0) {
return BOOT_EFLASH;
}
rc = boot_read_status_bytes(fap, state, bs);
if (rc == 0) {
off = boot_swap_info_off(fap);
rc = flash_area_read_is_empty(fap, off, &swap_info, sizeof swap_info);
if (rc == 1) {
BOOT_SET_SWAP_INFO(swap_info, 0, BOOT_SWAP_TYPE_NONE);
rc = 0;
}
/* Extract the swap type info */
bs->swap_type = BOOT_GET_SWAP_TYPE(swap_info);
}
flash_area_close(fap);
return rc;
}
/**
* Writes the supplied boot status to the flash file system. The boot status
* contains the current state of an in-progress image copy operation.
*
* @param bs The boot status to write.
*
* @return 0 on success; nonzero on failure.
*/
int
boot_write_status(struct boot_loader_state *state, struct boot_status *bs)
{
const struct flash_area *fap;
uint32_t off;
int area_id;
int rc;
uint8_t buf[BOOT_MAX_ALIGN];
uint8_t align;
uint8_t erased_val;
/* NOTE: The first sector copied (that is the last sector on slot) contains
* the trailer. Since in the last step the primary slot is erased, the
* first two status writes go to the scratch which will be copied to
* the primary slot!
*/
if (bs->use_scratch) {
/* Write to scratch. */
area_id = FLASH_AREA_IMAGE_SCRATCH;
} else {
/* Write to the primary slot. */
area_id = FLASH_AREA_IMAGE_PRIMARY(BOOT_CURR_IMG(state));
}
rc = flash_area_open(area_id, &fap);
if (rc != 0) {
rc = BOOT_EFLASH;
goto done;
}
off = boot_status_off(fap) +
boot_status_internal_off(bs->idx, bs->state,
BOOT_WRITE_SZ(state));
align = flash_area_align(fap);
erased_val = flash_area_erased_val(fap);
memset(buf, erased_val, BOOT_MAX_ALIGN);
buf[0] = bs->state;
rc = flash_area_write(fap, off, buf, align);
if (rc != 0) {
rc = BOOT_EFLASH;
goto done;
}
rc = 0;
done:
flash_area_close(fap);
return rc;
}
/*
* Validate image hash/signature in a slot.
*/
static int
boot_image_check(struct boot_loader_state *state, struct image_header *hdr,
const struct flash_area *fap, struct boot_status *bs)
{
TARGET_STATIC uint8_t tmpbuf[BOOT_TMPBUF_SZ];
uint8_t image_index;
int rc;
#if (BOOT_IMAGE_NUMBER == 1)
(void)state;
#endif
image_index = BOOT_CURR_IMG(state);
#ifndef MCUBOOT_ENC_IMAGES
(void)bs;
(void)rc;
if (bootutil_img_validate(NULL, image_index, hdr, fap, tmpbuf,
BOOT_TMPBUF_SZ, NULL, 0, NULL)) {
return BOOT_EBADIMAGE;
}
#else
if ((fap->fa_id == FLASH_AREA_IMAGE_SECONDARY(image_index))
&& IS_ENCRYPTED(hdr)) {
rc = boot_enc_load(state->enc, image_index, hdr, fap, bs->enckey[1]);
if (rc < 0) {
return BOOT_EBADIMAGE;
}
if (rc == 0 && boot_enc_set_key(state->enc, 1, bs->enckey[1])) {
return BOOT_EBADIMAGE;
}
}
if (bootutil_img_validate(state->enc, image_index, hdr, fap, tmpbuf,
BOOT_TMPBUF_SZ, NULL, 0, NULL)) {
return BOOT_EBADIMAGE;
}
#endif
return 0;
}
static int
split_image_check(struct image_header *app_hdr,
const struct flash_area *app_fap,
struct image_header *loader_hdr,
const struct flash_area *loader_fap)
{
static void *tmpbuf;
uint8_t loader_hash[32];
if (!tmpbuf) {
tmpbuf = malloc(BOOT_TMPBUF_SZ);
if (!tmpbuf) {
return BOOT_ENOMEM;
}
}
if (bootutil_img_validate(NULL, 0, loader_hdr, loader_fap, tmpbuf,
BOOT_TMPBUF_SZ, NULL, 0, loader_hash)) {
return BOOT_EBADIMAGE;
}
if (bootutil_img_validate(NULL, 0, app_hdr, app_fap, tmpbuf,
BOOT_TMPBUF_SZ, loader_hash, 32, NULL)) {
return BOOT_EBADIMAGE;
}
return 0;
}
/*
* Check that a memory area consists of a given value.
*/
static inline bool
boot_data_is_set_to(uint8_t val, void *data, size_t len)
{
uint8_t i;
uint8_t *p = (uint8_t *)data;
for (i = 0; i < len; i++) {
if (val != p[i]) {
return false;
}
}
return true;
}
static int
boot_check_header_erased(struct boot_loader_state *state, int slot)
{
const struct flash_area *fap;
struct image_header *hdr;
uint8_t erased_val;
int area_id;
int rc;
area_id = flash_area_id_from_multi_image_slot(BOOT_CURR_IMG(state), slot);
rc = flash_area_open(area_id, &fap);
if (rc != 0) {
return -1;
}
erased_val = flash_area_erased_val(fap);
flash_area_close(fap);
hdr = boot_img_hdr(state, slot);
if (!boot_data_is_set_to(erased_val, &hdr->ih_magic, sizeof(hdr->ih_magic))) {
return -1;
}
return 0;
}
static int
boot_validate_slot(struct boot_loader_state *state, int slot,
struct boot_status *bs)
{
const struct flash_area *fap;
struct image_header *hdr;
int area_id;
int rc;
area_id = flash_area_id_from_multi_image_slot(BOOT_CURR_IMG(state), slot);
rc = flash_area_open(area_id, &fap);
if (rc != 0) {
return BOOT_EFLASH;
}
hdr = boot_img_hdr(state, slot);
if (boot_check_header_erased(state, slot) == 0 ||
(hdr->ih_flags & IMAGE_F_NON_BOOTABLE)) {
/* No bootable image in slot; continue booting from the primary slot. */
rc = -1;
goto out;
}
if (hdr->ih_magic != IMAGE_MAGIC || boot_image_check(state, hdr, fap, bs)) {
if (slot != BOOT_PRIMARY_SLOT) {
flash_area_erase(fap, 0, fap->fa_size);
/* Image in the secondary slot is invalid. Erase the image and
* continue booting from the primary slot.
*/
}
BOOT_LOG_ERR("Image in the %s slot is not valid!",
(slot == BOOT_PRIMARY_SLOT) ? "primary" : "secondary");
rc = -1;
goto out;
}
/* Image in the secondary slot is valid. */
rc = 0;
out:
flash_area_close(fap);
return rc;
}
/**
* Determines which swap operation to perform, if any. If it is determined
* that a swap operation is required, the image in the secondary slot is checked
* for validity. If the image in the secondary slot is invalid, it is erased,
* and a swap type of "none" is indicated.
*
* @return The type of swap to perform (BOOT_SWAP_TYPE...)
*/
static int
boot_validated_swap_type(struct boot_loader_state *state,
struct boot_status *bs)
{
int swap_type;
#if (BOOT_IMAGE_NUMBER == 1)
swap_type = boot_swap_type();
#else
swap_type = boot_swap_type_multi(BOOT_CURR_IMG(state));
#endif
switch (swap_type) {
case BOOT_SWAP_TYPE_TEST:
case BOOT_SWAP_TYPE_PERM:
case BOOT_SWAP_TYPE_REVERT:
/* Boot loader wants to switch to the secondary slot.
* Ensure image is valid.
*/
if (boot_validate_slot(state, BOOT_SECONDARY_SLOT, bs) != 0) {
swap_type = BOOT_SWAP_TYPE_FAIL;
}
}
return swap_type;
}
/**
* Calculates the number of sectors the scratch area can contain. A "last"
* source sector is specified because images are copied backwards in flash
* (final index to index number 0).
*
* @param last_sector_idx The index of the last source sector
* (inclusive).
* @param out_first_sector_idx The index of the first source sector
* (inclusive) gets written here.
*
* @return The number of bytes comprised by the
* [first-sector, last-sector] range.
*/
#ifndef MCUBOOT_OVERWRITE_ONLY
static uint32_t
boot_copy_sz(struct boot_loader_state *state, int last_sector_idx,
int *out_first_sector_idx)
{
size_t scratch_sz;
uint32_t new_sz;
uint32_t sz;
int i;
sz = 0;
scratch_sz = boot_scratch_area_size(state);
for (i = last_sector_idx; i >= 0; i--) {
new_sz = sz + boot_img_sector_size(state, BOOT_PRIMARY_SLOT, i);
/*
* The secondary slot is not being checked here, because
* `boot_slots_compatible` already provides assurance that the copy size
* will be compatible with the primary slot and scratch.
*/
if (new_sz > scratch_sz) {
break;
}
sz = new_sz;
}
/* i currently refers to a sector that doesn't fit or it is -1 because all
* sectors have been processed. In both cases, exclude sector i.
*/
*out_first_sector_idx = i + 1;
return sz;
}
#endif /* !MCUBOOT_OVERWRITE_ONLY */
/**
* Erases a region of flash.
*
* @param flash_area The flash_area containing the region to erase.
* @param off The offset within the flash area to start the
* erase.
* @param sz The number of bytes to erase.
*
* @return 0 on success; nonzero on failure.
*/
static inline int
boot_erase_sector(const struct flash_area *fap, uint32_t off, uint32_t sz)
{
return flash_area_erase(fap, off, sz);
}
/**
* Copies the contents of one flash region to another. You must erase the
* destination region prior to calling this function.
*
* @param flash_area_id_src The ID of the source flash area.
* @param flash_area_id_dst The ID of the destination flash area.
* @param off_src The offset within the source flash area to
* copy from.
* @param off_dst The offset within the destination flash area to
* copy to.
* @param sz The number of bytes to copy.
*
* @return 0 on success; nonzero on failure.
*/
static int
boot_copy_sector(struct boot_loader_state *state,
const struct flash_area *fap_src,
const struct flash_area *fap_dst,
uint32_t off_src, uint32_t off_dst, uint32_t sz)
{
uint32_t bytes_copied;
int chunk_sz;
int rc;
#ifdef MCUBOOT_ENC_IMAGES
uint32_t off;
size_t blk_off;
struct image_header *hdr;
uint16_t idx;
uint32_t blk_sz;
uint8_t image_index;
#endif
TARGET_STATIC uint8_t buf[1024];
#if !defined(MCUBOOT_ENC_IMAGES)
(void)state;
#endif
bytes_copied = 0;
while (bytes_copied < sz) {
if (sz - bytes_copied > sizeof buf) {
chunk_sz = sizeof buf;
} else {
chunk_sz = sz - bytes_copied;
}
rc = flash_area_read(fap_src, off_src + bytes_copied, buf, chunk_sz);
if (rc != 0) {
return BOOT_EFLASH;
}
#ifdef MCUBOOT_ENC_IMAGES
image_index = BOOT_CURR_IMG(state);
if (fap_src->fa_id == FLASH_AREA_IMAGE_SECONDARY(image_index) ||
fap_dst->fa_id == FLASH_AREA_IMAGE_SECONDARY(image_index)) {
/* assume the secondary slot as src, needs decryption */
hdr = boot_img_hdr(state, BOOT_SECONDARY_SLOT);
off = off_src;
if (fap_dst->fa_id == FLASH_AREA_IMAGE_SECONDARY(image_index)) {
/* might need encryption (metadata from the primary slot) */
hdr = boot_img_hdr(state, BOOT_PRIMARY_SLOT);
off = off_dst;
}
if (IS_ENCRYPTED(hdr)) {
blk_sz = chunk_sz;
idx = 0;
if (off + bytes_copied < hdr->ih_hdr_size) {
/* do not decrypt header */
blk_off = 0;
blk_sz = chunk_sz - hdr->ih_hdr_size;
idx = hdr->ih_hdr_size;
} else {
blk_off = ((off + bytes_copied) - hdr->ih_hdr_size) & 0xf;
}
if (off + bytes_copied + chunk_sz > hdr->ih_hdr_size + hdr->ih_img_size) {
/* do not decrypt TLVs */
if (off + bytes_copied >= hdr->ih_hdr_size + hdr->ih_img_size) {
blk_sz = 0;
} else {
blk_sz = (hdr->ih_hdr_size + hdr->ih_img_size) - (off + bytes_copied);
}
}
boot_encrypt(state->enc, image_index, fap_src,
(off + bytes_copied + idx) - hdr->ih_hdr_size, blk_sz,
blk_off, &buf[idx]);
}
}
#endif
rc = flash_area_write(fap_dst, off_dst + bytes_copied, buf, chunk_sz);
if (rc != 0) {
return BOOT_EFLASH;
}
bytes_copied += chunk_sz;
MCUBOOT_WATCHDOG_FEED();
}
return 0;
}
#ifndef MCUBOOT_OVERWRITE_ONLY
static inline int
boot_status_init(const struct boot_loader_state *state,
const struct flash_area *fap,
const struct boot_status *bs)
{
struct boot_swap_state swap_state;
uint8_t image_index;
int rc;
#if (BOOT_IMAGE_NUMBER == 1)
(void)state;
#endif
image_index = BOOT_CURR_IMG(state);
BOOT_LOG_DBG("initializing status; fa_id=%d", fap->fa_id);
rc = boot_read_swap_state_by_id(FLASH_AREA_IMAGE_SECONDARY(image_index),
&swap_state);
assert(rc == 0);
if (bs->swap_type != BOOT_SWAP_TYPE_NONE) {
rc = boot_write_swap_info(fap, bs->swap_type, image_index);
assert(rc == 0);
}
if (swap_state.image_ok == BOOT_FLAG_SET) {
rc = boot_write_image_ok(fap);
assert(rc == 0);
}
rc = boot_write_swap_size(fap, bs->swap_size);
assert(rc == 0);
#ifdef MCUBOOT_ENC_IMAGES
rc = boot_write_enc_key(fap, 0, bs->enckey[0]);
assert(rc == 0);
rc = boot_write_enc_key(fap, 1, bs->enckey[1]);
assert(rc == 0);
#endif
rc = boot_write_magic(fap);
assert(rc == 0);
return 0;
}
#endif
#ifndef MCUBOOT_OVERWRITE_ONLY
static int
boot_erase_trailer_sectors(const struct boot_loader_state *state,
const struct flash_area *fap)
{
uint8_t slot;
uint32_t sector;
uint32_t trailer_sz;
uint32_t total_sz;
uint32_t off;
uint32_t sz;
int fa_id_primary;
int fa_id_secondary;
uint8_t image_index;
int rc;
BOOT_LOG_DBG("erasing trailer; fa_id=%d", fap->fa_id);
image_index = BOOT_CURR_IMG(state);
fa_id_primary = flash_area_id_from_multi_image_slot(image_index,
BOOT_PRIMARY_SLOT);
fa_id_secondary = flash_area_id_from_multi_image_slot(image_index,
BOOT_SECONDARY_SLOT);
if (fap->fa_id == fa_id_primary) {
slot = BOOT_PRIMARY_SLOT;
} else if (fap->fa_id == fa_id_secondary) {
slot = BOOT_SECONDARY_SLOT;
} else {
return BOOT_EFLASH;
}
/* delete starting from last sector and moving to beginning */
sector = boot_img_num_sectors(state, slot) - 1;
trailer_sz = boot_trailer_sz(BOOT_WRITE_SZ(state));
total_sz = 0;
do {
sz = boot_img_sector_size(state, slot, sector);
off = boot_img_sector_off(state, slot, sector);
rc = boot_erase_sector(fap, off, sz);
assert(rc == 0);
sector--;
total_sz += sz;
} while (total_sz < trailer_sz);
return rc;
}
#endif /* !MCUBOOT_OVERWRITE_ONLY */
/**
* Swaps the contents of two flash regions within the two image slots.
*
* @param idx The index of the first sector in the range of
* sectors being swapped.
* @param sz The number of bytes to swap.
* @param bs The current boot status. This struct gets
* updated according to the outcome.
*
* @return 0 on success; nonzero on failure.
*/
#ifndef MCUBOOT_OVERWRITE_ONLY
static void
boot_swap_sectors(int idx, uint32_t sz, struct boot_loader_state *state,
struct boot_status *bs)
{
const struct flash_area *fap_primary_slot;
const struct flash_area *fap_secondary_slot;
const struct flash_area *fap_scratch;
uint32_t copy_sz;
uint32_t trailer_sz;
uint32_t img_off;
uint32_t scratch_trailer_off;
struct boot_swap_state swap_state;
size_t last_sector;
bool erase_scratch;
uint8_t image_index;
int rc;
/* Calculate offset from start of image area. */
img_off = boot_img_sector_off(state, BOOT_PRIMARY_SLOT, idx);
copy_sz = sz;
trailer_sz = boot_trailer_sz(BOOT_WRITE_SZ(state));
/* sz in this function is always sized on a multiple of the sector size.
* The check against the start offset of the last sector
* is to determine if we're swapping the last sector. The last sector
* needs special handling because it's where the trailer lives. If we're
* copying it, we need to use scratch to write the trailer temporarily.
*
* NOTE: `use_scratch` is a temporary flag (never written to flash) which
* controls if special handling is needed (swapping last sector).
*/
last_sector = boot_img_num_sectors(state, BOOT_PRIMARY_SLOT) - 1;
if ((img_off + sz) >
boot_img_sector_off(state, BOOT_PRIMARY_SLOT, last_sector)) {
copy_sz -= trailer_sz;
}
bs->use_scratch = (bs->idx == BOOT_STATUS_IDX_0 && copy_sz != sz);
image_index = BOOT_CURR_IMG(state);
rc = flash_area_open(FLASH_AREA_IMAGE_PRIMARY(image_index),
&fap_primary_slot);
assert (rc == 0);
rc = flash_area_open(FLASH_AREA_IMAGE_SECONDARY(image_index),
&fap_secondary_slot);
assert (rc == 0);
rc = flash_area_open(FLASH_AREA_IMAGE_SCRATCH, &fap_scratch);
assert (rc == 0);
if (bs->state == BOOT_STATUS_STATE_0) {
BOOT_LOG_DBG("erasing scratch area");
rc = boot_erase_sector(fap_scratch, 0, fap_scratch->fa_size);
assert(rc == 0);
if (bs->idx == BOOT_STATUS_IDX_0) {
/* Write a trailer to the scratch area, even if we don't need the
* scratch area for status. We need a temporary place to store the
* `swap-type` while we erase the primary trailer.
*/
rc = boot_status_init(state, fap_scratch, bs);
assert(rc == 0);
if (!bs->use_scratch) {
/* Prepare the primary status area... here it is known that the
* last sector is not being used by the image data so it's safe
* to erase.
*/
rc = boot_erase_trailer_sectors(state, fap_primary_slot);
assert(rc == 0);
rc = boot_status_init(state, fap_primary_slot, bs);
assert(rc == 0);
/* Erase the temporary trailer from the scratch area. */
rc = boot_erase_sector(fap_scratch, 0, fap_scratch->fa_size);
assert(rc == 0);
}
}
rc = boot_copy_sector(state, fap_secondary_slot, fap_scratch,
img_off, 0, copy_sz);
assert(rc == 0);
bs->state = BOOT_STATUS_STATE_1;
rc = boot_write_status(state, bs);
BOOT_STATUS_ASSERT(rc == 0);
}
if (bs->state == BOOT_STATUS_STATE_1) {
rc = boot_erase_sector(fap_secondary_slot, img_off, sz);
assert(rc == 0);
rc = boot_copy_sector(state, fap_primary_slot, fap_secondary_slot,
img_off, img_off, copy_sz);
assert(rc == 0);
if (bs->idx == BOOT_STATUS_IDX_0 && !bs->use_scratch) {
/* If not all sectors of the slot are being swapped,
* guarantee here that only the primary slot will have the state.
*/
rc = boot_erase_trailer_sectors(state, fap_secondary_slot);
assert(rc == 0);
}
bs->state = BOOT_STATUS_STATE_2;
rc = boot_write_status(state, bs);
BOOT_STATUS_ASSERT(rc == 0);
}
if (bs->state == BOOT_STATUS_STATE_2) {
rc = boot_erase_sector(fap_primary_slot, img_off, sz);
assert(rc == 0);
/* NOTE: If this is the final sector, we exclude the image trailer from
* this copy (copy_sz was truncated earlier).
*/
rc = boot_copy_sector(state, fap_scratch, fap_primary_slot,
0, img_off, copy_sz);
assert(rc == 0);
if (bs->use_scratch) {
scratch_trailer_off = boot_status_off(fap_scratch);
/* copy current status that is being maintained in scratch */
rc = boot_copy_sector(state, fap_scratch, fap_primary_slot,
scratch_trailer_off, img_off + copy_sz,
BOOT_STATUS_STATE_COUNT * BOOT_WRITE_SZ(state));
BOOT_STATUS_ASSERT(rc == 0);
rc = boot_read_swap_state_by_id(FLASH_AREA_IMAGE_SCRATCH,
&swap_state);
assert(rc == 0);
if (swap_state.image_ok == BOOT_FLAG_SET) {
rc = boot_write_image_ok(fap_primary_slot);
assert(rc == 0);
}
if (swap_state.swap_type != BOOT_SWAP_TYPE_NONE) {
rc = boot_write_swap_info(fap_primary_slot,
swap_state.swap_type, image_index);
assert(rc == 0);
}
rc = boot_write_swap_size(fap_primary_slot, bs->swap_size);
assert(rc == 0);
#ifdef MCUBOOT_ENC_IMAGES
rc = boot_write_enc_key(fap_primary_slot, 0, bs->enckey[0]);
assert(rc == 0);
rc = boot_write_enc_key(fap_primary_slot, 1, bs->enckey[1]);
assert(rc == 0);
#endif
rc = boot_write_magic(fap_primary_slot);
assert(rc == 0);
}
/* If we wrote a trailer to the scratch area, erase it after we persist
* a trailer to the primary slot. We do this to prevent mcuboot from
* reading a stale status from the scratch area in case of immediate
* reset.
*/
erase_scratch = bs->use_scratch;
bs->use_scratch = 0;
bs->idx++;
bs->state = BOOT_STATUS_STATE_0;
rc = boot_write_status(state, bs);
BOOT_STATUS_ASSERT(rc == 0);
if (erase_scratch) {
rc = boot_erase_sector(fap_scratch, 0, sz);
assert(rc == 0);
}
}
flash_area_close(fap_primary_slot);
flash_area_close(fap_secondary_slot);
flash_area_close(fap_scratch);
}
#endif /* !MCUBOOT_OVERWRITE_ONLY */
/**
* Overwrite primary slot with the image contained in the secondary slot.
* If a prior copy operation was interrupted by a system reset, this function
* redos the copy.
*
* @param bs The current boot status. This function reads
* this struct to determine if it is resuming
* an interrupted swap operation. This
* function writes the updated status to this
* function on return.
*
* @return 0 on success; nonzero on failure.
*/
#if defined(MCUBOOT_OVERWRITE_ONLY) || defined(MCUBOOT_BOOTSTRAP)
static int
boot_copy_image(struct boot_loader_state *state, struct boot_status *bs)
{
size_t sect_count;
size_t sect;
int rc;
size_t size;
size_t this_size;
size_t last_sector;
const struct flash_area *fap_primary_slot;
const struct flash_area *fap_secondary_slot;
uint8_t image_index;
(void)bs;
#if defined(MCUBOOT_OVERWRITE_ONLY_FAST)
uint32_t src_size = 0;
rc = boot_read_image_size(state, BOOT_SECONDARY_SLOT,
boot_img_hdr(state, BOOT_SECONDARY_SLOT),
&src_size);
assert(rc == 0);
#endif
BOOT_LOG_INF("Image upgrade secondary slot -> primary slot");
BOOT_LOG_INF("Erasing the primary slot");
image_index = BOOT_CURR_IMG(state);
rc = flash_area_open(FLASH_AREA_IMAGE_PRIMARY(image_index),
&fap_primary_slot);
assert (rc == 0);
rc = flash_area_open(FLASH_AREA_IMAGE_SECONDARY(image_index),
&fap_secondary_slot);
assert (rc == 0);
sect_count = boot_img_num_sectors(state, BOOT_PRIMARY_SLOT);
for (sect = 0, size = 0; sect < sect_count; sect++) {
this_size = boot_img_sector_size(state, BOOT_PRIMARY_SLOT, sect);
rc = boot_erase_sector(fap_primary_slot, size, this_size);
assert(rc == 0);
size += this_size;
#if defined(MCUBOOT_OVERWRITE_ONLY_FAST)
if (size >= src_size) {
break;
}
#endif
}
#ifdef MCUBOOT_ENC_IMAGES
if (IS_ENCRYPTED(boot_img_hdr(state, BOOT_SECONDARY_SLOT))) {
rc = boot_enc_load(state->enc, image_index,
boot_img_hdr(state, BOOT_SECONDARY_SLOT),
fap_secondary_slot, bs->enckey[1]);
if (rc < 0) {
return BOOT_EBADIMAGE;
}
if (rc == 0 && boot_enc_set_key(state->enc, 1, bs->enckey[1])) {
return BOOT_EBADIMAGE;
}
}
#endif
BOOT_LOG_INF("Copying the secondary slot to the primary slot: 0x%zx bytes",
size);
rc = boot_copy_sector(state, fap_secondary_slot, fap_primary_slot, 0, 0, size);
/*
* Erases header and trailer. The trailer is erased because when a new
* image is written without a trailer as is the case when using newt, the
* trailer that was left might trigger a new upgrade.
*/
BOOT_LOG_DBG("erasing secondary header");
rc = boot_erase_sector(fap_secondary_slot,
boot_img_sector_off(state, BOOT_SECONDARY_SLOT, 0),
boot_img_sector_size(state, BOOT_SECONDARY_SLOT, 0));
assert(rc == 0);
last_sector = boot_img_num_sectors(state, BOOT_SECONDARY_SLOT) - 1;
BOOT_LOG_DBG("erasing secondary trailer");
rc = boot_erase_sector(fap_secondary_slot,
boot_img_sector_off(state, BOOT_SECONDARY_SLOT,
last_sector),
boot_img_sector_size(state, BOOT_SECONDARY_SLOT,
last_sector));
assert(rc == 0);
flash_area_close(fap_primary_slot);
flash_area_close(fap_secondary_slot);
/* TODO: Perhaps verify the primary slot's signature again? */
return 0;
}
#endif
#if !defined(MCUBOOT_OVERWRITE_ONLY)
/**
* Swaps the two images in flash. If a prior copy operation was interrupted
* by a system reset, this function completes that operation.
*
* @param bs The current boot status. This function reads
* this struct to determine if it is resuming
* an interrupted swap operation. This
* function writes the updated status to this
* function on return.
*
* @return 0 on success; nonzero on failure.
*/
static int
boot_swap_image(struct boot_loader_state *state, struct boot_status *bs)
{
uint32_t sz;
int first_sector_idx;
int last_sector_idx;
int last_idx_secondary_slot;
uint32_t swap_idx;
struct image_header *hdr;
#ifdef MCUBOOT_ENC_IMAGES
const struct flash_area *fap;
uint8_t slot;
uint8_t i;
#endif
uint32_t size;
uint32_t copy_size;
uint32_t primary_slot_size;
uint32_t secondary_slot_size;
uint8_t image_index;
int rc;
/* FIXME: just do this if asked by user? */
size = copy_size = 0;
image_index = BOOT_CURR_IMG(state);
if (bs->idx == BOOT_STATUS_IDX_0 && bs->state == BOOT_STATUS_STATE_0) {
/*
* No swap ever happened, so need to find the largest image which
* will be used to determine the amount of sectors to swap.
*/
hdr = boot_img_hdr(state, BOOT_PRIMARY_SLOT);
if (hdr->ih_magic == IMAGE_MAGIC) {
rc = boot_read_image_size(state, BOOT_PRIMARY_SLOT, hdr, &copy_size);
assert(rc == 0);
}
#ifdef MCUBOOT_ENC_IMAGES
if (IS_ENCRYPTED(hdr)) {
fap = BOOT_IMG_AREA(state, BOOT_PRIMARY_SLOT);
rc = boot_enc_load(state->enc, image_index, hdr, fap, bs->enckey[0]);
assert(rc >= 0);
if (rc == 0) {
rc = boot_enc_set_key(state->enc, 0, bs->enckey[0]);
assert(rc == 0);
} else {
rc = 0;
}
} else {
memset(bs->enckey[0], 0xff, BOOT_ENC_KEY_SIZE);
}
#endif
hdr = boot_img_hdr(state, BOOT_SECONDARY_SLOT);
if (hdr->ih_magic == IMAGE_MAGIC) {
rc = boot_read_image_size(state, BOOT_SECONDARY_SLOT, hdr, &size);
assert(rc == 0);
}
#ifdef MCUBOOT_ENC_IMAGES
hdr = boot_img_hdr(state, BOOT_SECONDARY_SLOT);
if (IS_ENCRYPTED(hdr)) {
fap = BOOT_IMG_AREA(state, BOOT_SECONDARY_SLOT);
rc = boot_enc_load(state->enc, image_index, hdr, fap, bs->enckey[1]);
assert(rc >= 0);
if (rc == 0) {
rc = boot_enc_set_key(state->enc, 1, bs->enckey[1]);
assert(rc == 0);
} else {
rc = 0;
}
} else {
memset(bs->enckey[1], 0xff, BOOT_ENC_KEY_SIZE);
}
#endif
if (size > copy_size) {
copy_size = size;
}
bs->swap_size = copy_size;
} else {
/*
* If a swap was under way, the swap_size should already be present
* in the trailer...
*/
rc = boot_read_swap_size(image_index, &bs->swap_size);
assert(rc == 0);
copy_size = bs->swap_size;
#ifdef MCUBOOT_ENC_IMAGES
for (slot = 0; slot <= 1; slot++) {
rc = boot_read_enc_key(image_index, slot, bs->enckey[slot]);
assert(rc == 0);
for (i = 0; i < BOOT_ENC_KEY_SIZE; i++) {
if (bs->enckey[slot][i] != 0xff) {
break;
}
}
if (i != BOOT_ENC_KEY_SIZE) {
boot_enc_set_key(state->enc, slot, bs->enckey[slot]);
}
}
#endif
}
primary_slot_size = 0;
secondary_slot_size = 0;
last_sector_idx = 0;
last_idx_secondary_slot = 0;
/*
* Knowing the size of the largest image between both slots, here we
* find what is the last sector in the primary slot that needs swapping.
* Since we already know that both slots are compatible, the secondary
* slot's last sector is not really required after this check is finished.
*/
while (1) {
if ((primary_slot_size < copy_size) ||
(primary_slot_size < secondary_slot_size)) {
primary_slot_size += boot_img_sector_size(state,
BOOT_PRIMARY_SLOT,
last_sector_idx);
}
if ((secondary_slot_size < copy_size) ||
(secondary_slot_size < primary_slot_size)) {
secondary_slot_size += boot_img_sector_size(state,
BOOT_SECONDARY_SLOT,
last_idx_secondary_slot);
}
if (primary_slot_size >= copy_size &&
secondary_slot_size >= copy_size &&
primary_slot_size == secondary_slot_size) {
break;
}
last_sector_idx++;
last_idx_secondary_slot++;
}
swap_idx = 0;
while (last_sector_idx >= 0) {
sz = boot_copy_sz(state, last_sector_idx, &first_sector_idx);
if (swap_idx >= (bs->idx - BOOT_STATUS_IDX_0)) {
boot_swap_sectors(first_sector_idx, sz, state, bs);
}
last_sector_idx = first_sector_idx - 1;
swap_idx++;
}
#ifdef MCUBOOT_VALIDATE_PRIMARY_SLOT
if (boot_status_fails > 0) {
BOOT_LOG_WRN("%d status write fails performing the swap",
boot_status_fails);
}
#endif
return 0;
}
#endif
/**
* Marks the image in the primary slot as fully copied.
*/
#ifndef MCUBOOT_OVERWRITE_ONLY
static int
boot_set_copy_done(uint8_t image_index)
{
const struct flash_area *fap;
int rc;
rc = flash_area_open(FLASH_AREA_IMAGE_PRIMARY(image_index),
&fap);
if (rc != 0) {
return BOOT_EFLASH;
}
rc = boot_write_copy_done(fap);
flash_area_close(fap);
return rc;
}
#endif /* !MCUBOOT_OVERWRITE_ONLY */
/**
* Marks a reverted image in the primary slot as confirmed. This is necessary to
* ensure the status bytes from the image revert operation don't get processed
* on a subsequent boot.
*
* NOTE: image_ok is tested before writing because if there's a valid permanent
* image installed on the primary slot and the new image to be upgrade to has a
* bad sig, image_ok would be overwritten.
*/
#ifndef MCUBOOT_OVERWRITE_ONLY
static int
boot_set_image_ok(uint8_t image_index)
{
const struct flash_area *fap;
struct boot_swap_state state;
int rc;
rc = flash_area_open(FLASH_AREA_IMAGE_PRIMARY(image_index),
&fap);
if (rc != 0) {
return BOOT_EFLASH;
}
rc = boot_read_swap_state(fap, &state);
if (rc != 0) {
rc = BOOT_EFLASH;
goto out;
}
if (state.image_ok == BOOT_FLAG_UNSET) {
rc = boot_write_image_ok(fap);
}
out:
flash_area_close(fap);
return rc;
}
#endif /* !MCUBOOT_OVERWRITE_ONLY */
#if (BOOT_IMAGE_NUMBER > 1)
/**
* Check the image dependency whether it is satisfied and modify
* the swap type if necessary.
*
* @param dep Image dependency which has to be verified.
*
* @return 0 on success; nonzero on failure.
*/
static int
boot_verify_single_dependency(struct boot_loader_state *state,
struct image_dependency *dep)
{
struct image_version *dep_version;
size_t dep_slot;
int rc;
/* Determine the source of the image which is the subject of
* the dependency and get it's version. */
dep_slot = (state->swap_type[dep->image_id] != BOOT_SWAP_TYPE_NONE) ?
BOOT_SECONDARY_SLOT : BOOT_PRIMARY_SLOT;
dep_version = &state->imgs[dep->image_id][dep_slot].hdr.ih_ver;
rc = boot_is_version_sufficient(&dep->image_min_version, dep_version);
if (rc != 0) {
/* Dependency not satisfied.
* Modify the swap type to decrease the version number of the image
* (which will be located in the primary slot after the boot process),
* consequently the number of unsatisfied dependencies will be
* decreased or remain the same.
*/
switch (BOOT_SWAP_TYPE(state)) {
case BOOT_SWAP_TYPE_TEST:
case BOOT_SWAP_TYPE_PERM:
BOOT_SWAP_TYPE(state) = BOOT_SWAP_TYPE_NONE;
break;
case BOOT_SWAP_TYPE_NONE:
BOOT_SWAP_TYPE(state) = BOOT_SWAP_TYPE_REVERT;
break;
default:
break;
}
}
return rc;
}
/**
* Read all dependency TLVs of an image from the flash and verify
* one after another to see if they are all satisfied.
*
* @param slot Image slot number.
*
* @return 0 on success; nonzero on failure.
*/
static int
boot_verify_all_dependency(struct boot_loader_state *state, uint32_t slot)
{
const struct flash_area *fap;
struct image_header *hdr;
struct image_tlv_info info;
struct image_tlv tlv;
struct image_dependency dep;
uint32_t off;
uint32_t end;
bool dep_tlvs_found = false;
int area_id;
int rc;
area_id = flash_area_id_from_multi_image_slot(BOOT_CURR_IMG(state), slot);
rc = flash_area_open(area_id, &fap);
if (rc != 0) {
rc = BOOT_EFLASH;
goto done;
}
hdr = boot_img_hdr(state, slot);
/* The TLVs come after the image. */
off = hdr->ih_hdr_size + hdr->ih_img_size;
/* The TLV area always starts with an image_tlv_info structure. */
rc = flash_area_read(fap, off, &info, sizeof(info));
if (rc != 0) {
rc = BOOT_EFLASH;
goto done;
}
if (info.it_magic != IMAGE_TLV_INFO_MAGIC) {
rc = BOOT_EBADIMAGE;
goto done;
}
end = off + info.it_tlv_tot;
off += sizeof(info);
/* Traverse through all of the TLVs to find the dependency TLVs. */
for (; off < end; off += sizeof(tlv) + tlv.it_len) {
rc = flash_area_read(fap, off, &tlv, sizeof(tlv));
if (rc != 0) {
rc = BOOT_EFLASH;
goto done;
}
if (tlv.it_type == IMAGE_TLV_DEPENDENCY) {
if (!dep_tlvs_found) {
dep_tlvs_found = true;
}
if (tlv.it_len != sizeof(dep)) {
rc = BOOT_EBADIMAGE;
goto done;
}
rc = flash_area_read(fap, off + sizeof(tlv), &dep, tlv.it_len);
if (rc != 0) {
rc = BOOT_EFLASH;
goto done;
}
/* Verify dependency and modify the swap type if not satisfied. */
rc = boot_verify_single_dependency(state, &dep);
if (rc != 0) {
/* Dependency not satisfied. */
goto done;
}
/* Dependency satisfied, no action needed.
* Continue with the next TLV entry.
*/
} else if (dep_tlvs_found) {
/* The dependency TLVs are contiguous in the TLV area. If a
* dependency had already been found and the last read TLV
* has a different type then there are no more dependency TLVs.
* The search can be finished.
*/
break;
}
}
done:
flash_area_close(fap);
return rc;
}
/**
* Verify whether the image dependencies in the TLV area are
* all satisfied and modify the swap type if necessary.
*
* @return 0 if all dependencies are satisfied,
* nonzero otherwise.
*/
static int
boot_verify_single_image_dependency(struct boot_loader_state *state)
{
size_t slot;
/* Determine the source of the dependency TLVs. Those dependencies have to
* be checked which belong to the image that will be located in the primary
* slot after the firmware update process.
*/
if (BOOT_SWAP_TYPE(state) != BOOT_SWAP_TYPE_NONE &&
BOOT_SWAP_TYPE(state) != BOOT_SWAP_TYPE_FAIL) {
slot = BOOT_SECONDARY_SLOT;
} else {
slot = BOOT_PRIMARY_SLOT;
}
return boot_verify_all_dependency(state, slot);
}
/**
* Iterate over all the images and verify whether the image dependencies in the
* TLV area are all satisfied and update the related swap type if necessary.
*/
static void
boot_verify_all_image_dependency(struct boot_loader_state *state)
{
int rc;
BOOT_CURR_IMG(state) = 0;
while (BOOT_CURR_IMG(state) < BOOT_IMAGE_NUMBER) {
rc = boot_verify_single_image_dependency(state);
if (rc == 0) {
/* All dependencies've been satisfied, continue with next image. */
BOOT_CURR_IMG(state)++;
} else if (rc == BOOT_EBADVERSION) {
/* Dependency check needs to be restarted. */
BOOT_CURR_IMG(state) = 0;
} else {
/* Other error happened, images are inconsistent */
return;
}
}
}
#endif /* (BOOT_IMAGE_NUMBER > 1) */
/**
* Performs a clean (not aborted) image update.
*
* @param bs The current boot status.
*
* @return 0 on success; nonzero on failure.
*/
static int
boot_perform_update(struct boot_loader_state *state, struct boot_status *bs)
{
int rc;
#ifndef MCUBOOT_OVERWRITE_ONLY
uint8_t swap_type;
#endif
/* At this point there are no aborted swaps. */
#if defined(MCUBOOT_OVERWRITE_ONLY)
rc = boot_copy_image(state, bs);
#elif defined(MCUBOOT_BOOTSTRAP)
/* Check if the image update was triggered by a bad image in the
* primary slot (the validity of the image in the secondary slot had
* already been checked).
*/
if (boot_check_header_erased(state, BOOT_PRIMARY_SLOT) == 0 ||
boot_validate_slot(state, BOOT_PRIMARY_SLOT, bs) != 0) {
rc = boot_copy_image(state, bs);
} else {
rc = boot_swap_image(state, bs);
}
#else
rc = boot_swap_image(state, bs);
#endif
assert(rc == 0);
#ifndef MCUBOOT_OVERWRITE_ONLY
/* The following state needs image_ok be explicitly set after the
* swap was finished to avoid a new revert.
*/
swap_type = BOOT_SWAP_TYPE(state);
if (swap_type == BOOT_SWAP_TYPE_REVERT ||
swap_type == BOOT_SWAP_TYPE_PERM) {
rc = boot_set_image_ok(BOOT_CURR_IMG(state));
if (rc != 0) {
BOOT_SWAP_TYPE(state) = swap_type = BOOT_SWAP_TYPE_PANIC;
}
}
if (swap_type == BOOT_SWAP_TYPE_TEST ||
swap_type == BOOT_SWAP_TYPE_PERM ||
swap_type == BOOT_SWAP_TYPE_REVERT) {
rc = boot_set_copy_done(BOOT_CURR_IMG(state));
if (rc != 0) {
BOOT_SWAP_TYPE(state) = BOOT_SWAP_TYPE_PANIC;
}
}
#endif /* !MCUBOOT_OVERWRITE_ONLY */
return rc;
}
/**
* Completes a previously aborted image swap.
*
* @param bs The current boot status.
*
* @return 0 on success; nonzero on failure.
*/
#if !defined(MCUBOOT_OVERWRITE_ONLY)
static int
boot_complete_partial_swap(struct boot_loader_state *state,
struct boot_status *bs)
{
int rc;
/* Determine the type of swap operation being resumed from the
* `swap-type` trailer field.
*/
rc = boot_swap_image(state, bs);
assert(rc == 0);
BOOT_SWAP_TYPE(state) = bs->swap_type;
/* The following states need image_ok be explicitly set after the
* swap was finished to avoid a new revert.
*/
if (bs->swap_type == BOOT_SWAP_TYPE_REVERT ||
bs->swap_type == BOOT_SWAP_TYPE_PERM) {
rc = boot_set_image_ok(BOOT_CURR_IMG(state));
if (rc != 0) {
BOOT_SWAP_TYPE(state) = BOOT_SWAP_TYPE_PANIC;
}
}
if (bs->swap_type == BOOT_SWAP_TYPE_TEST ||
bs->swap_type == BOOT_SWAP_TYPE_PERM ||
bs->swap_type == BOOT_SWAP_TYPE_REVERT) {
rc = boot_set_copy_done(BOOT_CURR_IMG(state));
if (rc != 0) {
BOOT_SWAP_TYPE(state) = BOOT_SWAP_TYPE_PANIC;
}
}
if (BOOT_SWAP_TYPE(state) == BOOT_SWAP_TYPE_PANIC) {
BOOT_LOG_ERR("panic!");
assert(0);
/* Loop forever... */
while (1) {}
}
return rc;
}
#endif /* !MCUBOOT_OVERWRITE_ONLY */
#if (BOOT_IMAGE_NUMBER > 1)
/**
* Review the validity of previously determined swap types of other images.
*
* @param aborted_swap The current image upgrade is a
* partial/aborted swap.
*/
static void
boot_review_image_swap_types(struct boot_loader_state *state,
bool aborted_swap)
{
/* In that case if we rebooted in the middle of an image upgrade process, we
* must review the validity of swap types, that were previously determined
* for other images. The image_ok flag had not been set before the reboot
* for any of the updated images (only the copy_done flag) and thus falsely
* the REVERT swap type has been determined for the previous images that had
* been updated before the reboot.
*
* There are two separate scenarios that we have to deal with:
*
* 1. The reboot has happened during swapping an image:
* The current image upgrade has been determined as a
* partial/aborted swap.
* 2. The reboot has happened between two separate image upgrades:
* In this scenario we must check the swap type of the current image.
* In those cases if it is NONE or REVERT we cannot certainly determine
* the fact of a reboot. In a consistent state images must move in the
* same direction or stay in place, e.g. in practice REVERT and TEST
* swap types cannot be present at the same time. If the swap type of
* the current image is either TEST, PERM or FAIL we must review the
* already determined swap types of other images and set each false
* REVERT swap types to NONE (these images had been successfully
* updated before the system rebooted between two separate image
* upgrades).
*/
if (BOOT_CURR_IMG(state) == 0) {
/* Nothing to do */
return;
}
if (!aborted_swap) {
if ((BOOT_SWAP_TYPE(state) == BOOT_SWAP_TYPE_NONE) ||
(BOOT_SWAP_TYPE(state) == BOOT_SWAP_TYPE_REVERT)) {
/* Nothing to do */
return;
}
}
for (uint8_t i = 0; i < BOOT_CURR_IMG(state); i++) {
if (state->swap_type[i] == BOOT_SWAP_TYPE_REVERT) {
state->swap_type[i] = BOOT_SWAP_TYPE_NONE;
}
}
}
#endif
/**
* Prepare image to be updated if required.
*
* Prepare image to be updated if required with completing an image swap
* operation if one was aborted and/or determining the type of the
* swap operation. In case of any error set the swap type to NONE.
*
* @param state TODO
* @param bs Pointer where the read and possibly updated
* boot status can be written to.
*/
static void
boot_prepare_image_for_update(struct boot_loader_state *state,
struct boot_status *bs)
{
int rc;
/* Determine the sector layout of the image slots and scratch area. */
rc = boot_read_sectors(state);
if (rc != 0) {
BOOT_LOG_WRN("Failed reading sectors; BOOT_MAX_IMG_SECTORS=%d"
" - too small?", BOOT_MAX_IMG_SECTORS);
/* Unable to determine sector layout, continue with next image
* if there is one.
*/
BOOT_SWAP_TYPE(state) = BOOT_SWAP_TYPE_NONE;
return;
}
/* Attempt to read an image header from each slot. */
rc = boot_read_image_headers(state, false);
if (rc != 0) {
/* Continue with next image if there is one. */
BOOT_LOG_WRN("Failed reading image headers; Image=%u",
BOOT_CURR_IMG(state));
BOOT_SWAP_TYPE(state) = BOOT_SWAP_TYPE_NONE;
return;
}
/* If the current image's slots aren't compatible, no swap is possible.
* Just boot into primary slot.
*/
if (boot_slots_compatible(state)) {
rc = boot_read_status(state, bs);
if (rc != 0) {
BOOT_LOG_WRN("Failed reading boot status; Image=%u",
BOOT_CURR_IMG(state));
/* Continue with next image if there is one. */
BOOT_SWAP_TYPE(state) = BOOT_SWAP_TYPE_NONE;
return;
}
/* Determine if we rebooted in the middle of an image swap
* operation. If a partial swap was detected, complete it.
*/
if (bs->idx != BOOT_STATUS_IDX_0 || bs->state != BOOT_STATUS_STATE_0) {
#if (BOOT_IMAGE_NUMBER > 1)
boot_review_image_swap_types(state, true);
#endif
#ifdef MCUBOOT_OVERWRITE_ONLY
/* Should never arrive here, overwrite-only mode has
* no swap state.
*/
assert(0);
#else
/* Determine the type of swap operation being resumed from the
* `swap-type` trailer field.
*/
rc = boot_complete_partial_swap(state, bs);
assert(rc == 0);
#endif
/* Attempt to read an image header from each slot. Ensure that
* image headers in slots are aligned with headers in boot_data.
*/
rc = boot_read_image_headers(state, false);
assert(rc == 0);
/* Swap has finished set to NONE */
BOOT_SWAP_TYPE(state) = BOOT_SWAP_TYPE_NONE;
} else {
/* There was no partial swap, determine swap type. */
if (bs->swap_type == BOOT_SWAP_TYPE_NONE) {
BOOT_SWAP_TYPE(state) = boot_validated_swap_type(state, bs);
} else if (boot_validate_slot(state, BOOT_SECONDARY_SLOT, bs) != 0) {
BOOT_SWAP_TYPE(state) = BOOT_SWAP_TYPE_FAIL;
} else {
BOOT_SWAP_TYPE(state) = bs->swap_type;
}
#if (BOOT_IMAGE_NUMBER > 1)
boot_review_image_swap_types(state, false);
#endif
#ifdef MCUBOOT_BOOTSTRAP
if (BOOT_SWAP_TYPE(state) == BOOT_SWAP_TYPE_NONE) {
/* Header checks are done first because they are
* inexpensive. Since overwrite-only copies starting from
* offset 0, if interrupted, it might leave a valid header
* magic, so also run validation on the primary slot to be
* sure it's not OK.
*/
if (boot_check_header_erased(state, BOOT_PRIMARY_SLOT) == 0 ||
boot_validate_slot(state, BOOT_PRIMARY_SLOT, bs) != 0) {
if (boot_img_hdr(state,
BOOT_SECONDARY_SLOT)->ih_magic == IMAGE_MAGIC &&
boot_validate_slot(state, BOOT_SECONDARY_SLOT, bs) == 0)
{
/* Set swap type to REVERT to overwrite the primary
* slot with the image contained in secondary slot
* and to trigger the explicit setting of the
* image_ok flag.
*/
BOOT_SWAP_TYPE(state) = BOOT_SWAP_TYPE_REVERT;
}
}
}
#endif
}
} else {
/* In that case if slots are not compatible. */
BOOT_SWAP_TYPE(state) = BOOT_SWAP_TYPE_NONE;
}
}
int
context_boot_go(struct boot_loader_state *state, struct boot_rsp *rsp)
{
size_t slot;
struct boot_status bs;
int rc;
int fa_id;
int image_index;
/* The array of slot sectors are defined here (as opposed to file scope) so
* that they don't get allocated for non-boot-loader apps. This is
* necessary because the gcc option "-fdata-sections" doesn't seem to have
* any effect in older gcc versions (e.g., 4.8.4).
*/
TARGET_STATIC boot_sector_t primary_slot_sectors[BOOT_IMAGE_NUMBER][BOOT_MAX_IMG_SECTORS];
TARGET_STATIC boot_sector_t secondary_slot_sectors[BOOT_IMAGE_NUMBER][BOOT_MAX_IMG_SECTORS];
TARGET_STATIC boot_sector_t scratch_sectors[BOOT_MAX_IMG_SECTORS];
memset(state, 0, sizeof(struct boot_loader_state));
/* Iterate over all the images. By the end of the loop the swap type has
* to be determined for each image and all aborted swaps have to be
* completed.
*/
IMAGES_ITER(BOOT_CURR_IMG(state)) {
#if defined(MCUBOOT_ENC_IMAGES) && (BOOT_IMAGE_NUMBER > 1)
/* The keys used for encryption may no longer be valid (could belong to
* another images). Therefore, mark them as invalid to force their reload
* by boot_enc_load().
*/
boot_enc_mark_keys_invalid(state->enc);
#endif
image_index = BOOT_CURR_IMG(state);
BOOT_IMG(state, BOOT_PRIMARY_SLOT).sectors =
primary_slot_sectors[image_index];
BOOT_IMG(state, BOOT_SECONDARY_SLOT).sectors =
secondary_slot_sectors[image_index];
state->scratch.sectors = scratch_sectors;
/* Open primary and secondary image areas for the duration
* of this call.
*/
for (slot = 0; slot < BOOT_NUM_SLOTS; slot++) {
fa_id = flash_area_id_from_multi_image_slot(image_index, slot);
rc = flash_area_open(fa_id, &BOOT_IMG_AREA(state, slot));
assert(rc == 0);
}
rc = flash_area_open(FLASH_AREA_IMAGE_SCRATCH,
&BOOT_SCRATCH_AREA(state));
assert(rc == 0);
/* Determine swap type and complete swap if it has been aborted. */
boot_prepare_image_for_update(state, &bs);
}
#if (BOOT_IMAGE_NUMBER > 1)
/* Iterate over all the images and verify whether the image dependencies
* are all satisfied and update swap type if necessary.
*/
boot_verify_all_image_dependency(state);
#endif
/* Iterate over all the images. At this point there are no aborted swaps
* and the swap types are determined for each image. By the end of the loop
* all required update operations will have been finished.
*/
IMAGES_ITER(BOOT_CURR_IMG(state)) {
#if (BOOT_IMAGE_NUMBER > 1)
#ifdef MCUBOOT_ENC_IMAGES
/* The keys used for encryption may no longer be valid (could belong to
* another images). Therefore, mark them as invalid to force their reload
* by boot_enc_load().
*/
boot_enc_mark_keys_invalid();
#endif /* MCUBOOT_ENC_IMAGES */
/* Indicate that swap is not aborted */
memset(&bs, 0, sizeof bs);
bs.idx = BOOT_STATUS_IDX_0;
bs.state = BOOT_STATUS_STATE_0;
#endif /* (BOOT_IMAGE_NUMBER > 1) */
/* Set the previously determined swap type */
bs.swap_type = BOOT_SWAP_TYPE(state);
switch (BOOT_SWAP_TYPE(state)) {
case BOOT_SWAP_TYPE_NONE:
break;
case BOOT_SWAP_TYPE_TEST: /* fallthrough */
case BOOT_SWAP_TYPE_PERM: /* fallthrough */
case BOOT_SWAP_TYPE_REVERT:
rc = boot_perform_update(state, &bs);
assert(rc == 0);
break;
case BOOT_SWAP_TYPE_FAIL:
/* The image in secondary slot was invalid and is now erased. Ensure
* we don't try to boot into it again on the next reboot. Do this by
* pretending we just reverted back to primary slot.
*/
#ifndef MCUBOOT_OVERWRITE_ONLY
/* image_ok needs to be explicitly set to avoid a new revert. */
rc = boot_set_image_ok(BOOT_CURR_IMG(state));
if (rc != 0) {
BOOT_SWAP_TYPE(state) = BOOT_SWAP_TYPE_PANIC;
}
#endif /* !MCUBOOT_OVERWRITE_ONLY */
break;
default:
BOOT_SWAP_TYPE(state) = BOOT_SWAP_TYPE_PANIC;
}
if (BOOT_SWAP_TYPE(state) == BOOT_SWAP_TYPE_PANIC) {
BOOT_LOG_ERR("panic!");
assert(0);
/* Loop forever... */
while (1) {}
}
}
/* Iterate over all the images. At this point all required update operations
* have finished. By the end of the loop each image in the primary slot will
* have been re-validated.
*/
IMAGES_ITER(BOOT_CURR_IMG(state)) {
if (BOOT_SWAP_TYPE(state) != BOOT_SWAP_TYPE_NONE) {
/* Attempt to read an image header from each slot. Ensure that image
* headers in slots are aligned with headers in boot_data.
*/
rc = boot_read_image_headers(state, false);
if (rc != 0) {
goto out;
}
/* Since headers were reloaded, it can be assumed we just performed
* a swap or overwrite. Now the header info that should be used to
* provide the data for the bootstrap, which previously was at
* secondary slot, was updated to primary slot.
*/
}
#ifdef MCUBOOT_VALIDATE_PRIMARY_SLOT
rc = boot_validate_slot(state, BOOT_PRIMARY_SLOT, NULL);
if (rc != 0) {
rc = BOOT_EBADIMAGE;
goto out;
}
#else
/* Even if we're not re-validating the primary slot, we could be booting
* onto an empty flash chip. At least do a basic sanity check that
* the magic number on the image is OK.
*/
if (BOOT_IMG(state, BOOT_PRIMARY_SLOT).hdr.ih_magic != IMAGE_MAGIC) {
BOOT_LOG_ERR("bad image magic 0x%lx; Image=%u", (unsigned long)
&boot_img_hdr(state,BOOT_PRIMARY_SLOT)->ih_magic,
BOOT_CURR_IMG(state));
rc = BOOT_EBADIMAGE;
goto out;
}
#endif
}
#if (BOOT_IMAGE_NUMBER > 1)
/* Always boot from the primary slot of Image 0. */
BOOT_CURR_IMG(state) = 0;
#endif
rsp->br_flash_dev_id = BOOT_IMG_AREA(state, BOOT_PRIMARY_SLOT)->fa_device_id;
rsp->br_image_off = boot_img_slot_off(state, BOOT_PRIMARY_SLOT);
rsp->br_hdr = boot_img_hdr(state, BOOT_PRIMARY_SLOT);
out:
IMAGES_ITER(BOOT_CURR_IMG(state)) {
flash_area_close(BOOT_SCRATCH_AREA(state));
for (slot = 0; slot < BOOT_NUM_SLOTS; slot++) {
flash_area_close(BOOT_IMG_AREA(state, BOOT_NUM_SLOTS - 1 - slot));
}
}
return rc;
}
/**
* Prepares the booting process. This function moves images around in flash as
* appropriate, and tells you what address to boot from.
*
* @param rsp On success, indicates how booting should occur.
*
* @return 0 on success; nonzero on failure.
*/
int
boot_go(struct boot_rsp *rsp)
{
return context_boot_go(&boot_data, rsp);
}
int
split_go(int loader_slot, int split_slot, void **entry)
{
boot_sector_t *sectors;
uintptr_t entry_val;
int loader_flash_id;
int split_flash_id;
int rc;
sectors = malloc(BOOT_MAX_IMG_SECTORS * 2 * sizeof *sectors);
if (sectors == NULL) {
return SPLIT_GO_ERR;
}
BOOT_IMG(&boot_data, loader_slot).sectors = sectors + 0;
BOOT_IMG(&boot_data, split_slot).sectors = sectors + BOOT_MAX_IMG_SECTORS;
loader_flash_id = flash_area_id_from_image_slot(loader_slot);
rc = flash_area_open(loader_flash_id,
&BOOT_IMG_AREA(&boot_data, loader_slot));
assert(rc == 0);
split_flash_id = flash_area_id_from_image_slot(split_slot);
rc = flash_area_open(split_flash_id,
&BOOT_IMG_AREA(&boot_data, split_slot));
assert(rc == 0);
/* Determine the sector layout of the image slots and scratch area. */
rc = boot_read_sectors(&boot_data);
if (rc != 0) {
rc = SPLIT_GO_ERR;
goto done;
}
rc = boot_read_image_headers(&boot_data, true);
if (rc != 0) {
goto done;
}
/* Don't check the bootable image flag because we could really call a
* bootable or non-bootable image. Just validate that the image check
* passes which is distinct from the normal check.
*/
rc = split_image_check(boot_img_hdr(&boot_data, split_slot),
BOOT_IMG_AREA(&boot_data, split_slot),
boot_img_hdr(&boot_data, loader_slot),
BOOT_IMG_AREA(&boot_data, loader_slot));
if (rc != 0) {
rc = SPLIT_GO_NON_MATCHING;
goto done;
}
entry_val = boot_img_slot_off(&boot_data, split_slot) +
boot_img_hdr(&boot_data, split_slot)->ih_hdr_size;
*entry = (void *) entry_val;
rc = SPLIT_GO_OK;
done:
flash_area_close(BOOT_IMG_AREA(&boot_data, split_slot));
flash_area_close(BOOT_IMG_AREA(&boot_data, loader_slot));
free(sectors);
return rc;
}