mcuboot - Initial migration.
diff --git a/bootutil/src/loader.c b/bootutil/src/loader.c
new file mode 100644
index 0000000..4d17291
--- /dev/null
+++ b/bootutil/src/loader.c
@@ -0,0 +1,1100 @@
+/*
+ * 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.
+ */
+
+/**
+ * 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 <inttypes.h>
+#include <stdlib.h>
+#include <string.h>
+#include "sysflash/sysflash.h"
+#include "flash_map/flash_map.h"
+#include <hal/hal_flash.h>
+#include <os/os_malloc.h>
+#include "bootutil/bootutil.h"
+#include "bootutil/image.h"
+#include "bootutil_priv.h"
+
+#define BOOT_MAX_IMG_SECTORS 120
+
+/** Number of image slots in flash; currently limited to two. */
+#define BOOT_NUM_SLOTS 2
+
+static struct {
+ struct {
+ struct image_header hdr;
+ struct flash_area *sectors;
+ } imgs[BOOT_NUM_SLOTS];
+
+ int num_img_sectors;
+ struct flash_area scratch_sector;
+
+ uint8_t write_sz;
+} boot_data;
+
+struct boot_status_table {
+ /**
+ * For each field, a value of 0 means "any".
+ */
+ uint8_t bst_magic_slot0;
+ uint8_t bst_magic_scratch;
+ uint8_t bst_copy_done_slot0;
+ 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[] = {
+ {
+ /* | slot-0 | scratch |
+ * ----------+------------+------------|
+ * magic | Good | Any |
+ * copy-done | 0x01 | N/A |
+ * ----------+------------+------------'
+ * source: none |
+ * ------------------------------------'
+ */
+ .bst_magic_slot0 = BOOT_MAGIC_GOOD,
+ .bst_magic_scratch = 0,
+ .bst_copy_done_slot0 = 0x01,
+ .bst_status_source = BOOT_STATUS_SOURCE_NONE,
+ },
+
+ {
+ /* | slot-0 | scratch |
+ * ----------+------------+------------|
+ * magic | Good | Any |
+ * copy-done | 0xff | N/A |
+ * ----------+------------+------------'
+ * source: slot 0 |
+ * ------------------------------------'
+ */
+ .bst_magic_slot0 = BOOT_MAGIC_GOOD,
+ .bst_magic_scratch = 0,
+ .bst_copy_done_slot0 = 0xff,
+ .bst_status_source = BOOT_STATUS_SOURCE_SLOT0,
+ },
+
+ {
+ /* | slot-0 | scratch |
+ * ----------+------------+------------|
+ * magic | Any | Good |
+ * copy-done | Any | N/A |
+ * ----------+------------+------------'
+ * source: scratch |
+ * ------------------------------------'
+ */
+ .bst_magic_slot0 = 0,
+ .bst_magic_scratch = BOOT_MAGIC_GOOD,
+ .bst_copy_done_slot0 = 0,
+ .bst_status_source = BOOT_STATUS_SOURCE_SCRATCH,
+ },
+
+ {
+ /* | slot-0 | scratch |
+ * ----------+------------+------------|
+ * magic | Unset | Any |
+ * copy-done | 0xff | 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 slot 0. |
+ * -------------------------------------------------------------------'
+ */
+ .bst_magic_slot0 = BOOT_MAGIC_UNSET,
+ .bst_magic_scratch = 0,
+ .bst_copy_done_slot0 = 0xff,
+ .bst_status_source = BOOT_STATUS_SOURCE_SLOT0,
+ },
+};
+
+#define BOOT_STATUS_TABLES_COUNT \
+ (sizeof boot_status_tables / sizeof boot_status_tables[0])
+
+/**
+ * This table indicates the next swap type that should be performed. The first
+ * column contains the current swap type. The second column contains the swap
+ * type that should be effected after the first completes.
+ */
+static const uint8_t boot_swap_trans_table[][2] = {
+ /* From To */
+ { BOOT_SWAP_TYPE_REVERT, BOOT_SWAP_TYPE_NONE },
+ { BOOT_SWAP_TYPE_TEST, BOOT_SWAP_TYPE_REVERT },
+};
+
+#define BOOT_SWAP_TRANS_TABLE_SIZE \
+ (sizeof boot_swap_trans_table / sizeof boot_swap_trans_table[0])
+
+/**
+ * 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(void)
+{
+ const struct boot_status_table *table;
+ struct boot_swap_state state_scratch;
+ struct boot_swap_state state_slot0;
+ struct boot_swap_state state_slot1;
+ int rc;
+ int i;
+
+ rc = boot_read_swap_state_img(0, &state_slot0);
+ assert(rc == 0);
+
+ rc = boot_read_swap_state_img(1, &state_slot1);
+ assert(rc == 0);
+
+ rc = boot_read_swap_state_scratch(&state_scratch);
+ assert(rc == 0);
+
+ for (i = 0; i < BOOT_STATUS_TABLES_COUNT; i++) {
+ table = boot_status_tables + i;
+
+ if ((table->bst_magic_slot0 == 0 ||
+ table->bst_magic_slot0 == state_slot0.magic) &&
+ (table->bst_magic_scratch == 0 ||
+ table->bst_magic_scratch == state_scratch.magic) &&
+ (table->bst_copy_done_slot0 == 0 ||
+ table->bst_copy_done_slot0 == state_slot0.copy_done)) {
+
+ return table->bst_status_source;
+ }
+ }
+
+ return BOOT_STATUS_SOURCE_NONE;
+}
+
+/**
+ * Calculates the type of swap that just completed.
+ */
+static int
+boot_previous_swap_type(void)
+{
+ int post_swap_type;
+ int i;
+
+ post_swap_type = boot_swap_type();
+
+ for (i = 0; i < BOOT_SWAP_TRANS_TABLE_SIZE; i++){
+ if (boot_swap_trans_table[i][1] == post_swap_type) {
+ return boot_swap_trans_table[i][0];
+ }
+ }
+
+ /* XXX: Temporary assert. */
+ assert(0);
+
+ return BOOT_SWAP_TYPE_REVERT;
+}
+
+static int
+boot_read_image_header(int slot, struct image_header *out_hdr)
+{
+ const struct flash_area *fap;
+ int area_id;
+ int rc;
+
+ area_id = flash_area_id_from_image_slot(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(void)
+{
+ int rc;
+ int i;
+
+ for (i = 0; i < BOOT_NUM_SLOTS; i++) {
+ rc = boot_read_image_header(i, &boot_data.imgs[i].hdr);
+ if (rc != 0) {
+ return rc;
+ }
+ }
+
+ return 0;
+}
+
+static uint8_t
+boot_write_sz(void)
+{
+ 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 = hal_flash_align(boot_data.imgs[0].sectors[0].fa_device_id);
+ align = hal_flash_align(boot_data.scratch_sector.fa_device_id);
+ if (align > elem_sz) {
+ elem_sz = align;
+ }
+
+ return elem_sz;
+}
+
+/**
+ * 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 boot_data global.
+ */
+static int
+boot_read_sectors(void)
+{
+ const struct flash_area *sector0;
+ const struct flash_area *sector1;
+ const struct flash_area *scratch;
+ int num_sectors_slot0;
+ int num_sectors_slot1;
+ int rc;
+ int i;
+
+ num_sectors_slot0 = BOOT_MAX_IMG_SECTORS;
+ rc = flash_area_to_sectors(FLASH_AREA_IMAGE_0, &num_sectors_slot0,
+ boot_data.imgs[0].sectors);
+ if (rc != 0) {
+ return BOOT_EFLASH;
+ }
+
+ num_sectors_slot1 = BOOT_MAX_IMG_SECTORS;
+ rc = flash_area_to_sectors(FLASH_AREA_IMAGE_1, &num_sectors_slot1,
+ boot_data.imgs[1].sectors);
+ if (rc != 0) {
+ return BOOT_EFLASH;
+ }
+
+ rc = flash_area_open(FLASH_AREA_IMAGE_SCRATCH, &scratch);
+ if (rc != 0) {
+ return BOOT_EFLASH;
+ }
+ boot_data.scratch_sector = *scratch;
+ boot_data.write_sz = hal_flash_align(scratch->fa_device_id);
+
+ /* Ensure both image slots have identical sector layouts. */
+ if (num_sectors_slot0 != num_sectors_slot1) {
+ return BOOT_EFLASH;
+ }
+ for (i = 0; i < num_sectors_slot0; i++) {
+ sector0 = boot_data.imgs[0].sectors + i;
+ sector1 = boot_data.imgs[1].sectors + i;
+ if (sector0->fa_size != sector1->fa_size) {
+ return BOOT_EFLASH;
+ }
+ }
+
+ boot_data.num_img_sectors = num_sectors_slot0;
+
+ boot_data.write_sz = boot_write_sz();
+
+ 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 * idx_sz + state * 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_status *bs)
+{
+ uint32_t off;
+ uint8_t status;
+ int found;
+ int rc;
+ int i;
+
+ off = boot_status_off(fap);
+
+ found = 0;
+ for (i = 0; i < BOOT_STATUS_MAX_ENTRIES; i++) {
+ rc = flash_area_read(fap, off + i * boot_data.write_sz, &status, 1);
+ if (rc != 0) {
+ return BOOT_EFLASH;
+ }
+
+ if (status == 0xff) {
+ if (found) {
+ break;
+ }
+ } else if (!found) {
+ found = 1;
+ }
+ }
+
+ if (found) {
+ i--;
+ bs->idx = i / BOOT_STATUS_STATE_COUNT;
+ bs->state = i % BOOT_STATUS_STATE_COUNT;
+ }
+
+ 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_status *bs)
+{
+ const struct flash_area *fap;
+ int status_loc;
+ int area_id;
+ int rc;
+
+ memset(bs, 0, sizeof *bs);
+
+ status_loc = boot_status_source();
+ 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_SLOT0:
+ area_id = FLASH_AREA_IMAGE_0;
+ 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, bs);
+ if (rc != 0) {
+ return rc;
+ }
+
+ return 0;
+}
+
+/**
+ * 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_status *bs)
+{
+ const struct flash_area *fap;
+ uint32_t off;
+ int area_id;
+ int rc;
+
+ if (bs->idx == 0) {
+ /* Write to scratch. */
+ area_id = FLASH_AREA_IMAGE_SCRATCH;
+ } else {
+ /* Write to slot 0. */
+ area_id = FLASH_AREA_IMAGE_0;
+ }
+
+ 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_data.write_sz);
+
+ rc = flash_area_write(fap, off, &bs->state, 1);
+ 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 image_header *hdr, const struct flash_area *fap)
+{
+ static void *tmpbuf;
+
+ if (!tmpbuf) {
+ tmpbuf = malloc(BOOT_TMPBUF_SZ);
+ if (!tmpbuf) {
+ return BOOT_ENOMEM;
+ }
+ }
+ if (bootutil_img_validate(hdr, fap, tmpbuf, BOOT_TMPBUF_SZ,
+ NULL, 0, NULL)) {
+ return BOOT_EBADIMAGE;
+ }
+ 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(loader_hdr, loader_fap, tmpbuf, BOOT_TMPBUF_SZ,
+ NULL, 0, loader_hash)) {
+ return BOOT_EBADIMAGE;
+ }
+
+ if (bootutil_img_validate(app_hdr, app_fap, tmpbuf, BOOT_TMPBUF_SZ,
+ loader_hash, 32, NULL)) {
+ return BOOT_EBADIMAGE;
+ }
+
+ return 0;
+}
+
+static int
+boot_validate_slot1(void)
+{
+ const struct flash_area *fap;
+ int rc;
+
+ if (boot_data.imgs[1].hdr.ih_magic == 0xffffffff ||
+ boot_data.imgs[1].hdr.ih_flags & IMAGE_F_NON_BOOTABLE) {
+
+ /* No bootable image in slot 1; continue booting from slot 0. */
+ return -1;
+ }
+
+ /* Image in slot 1 is invalid. Erase the image and continue booting
+ * from slot 0.
+ */
+ rc = flash_area_open(FLASH_AREA_IMAGE_1, &fap);
+ if (rc != 0) {
+ return BOOT_EFLASH;
+ }
+
+ if (boot_data.imgs[1].hdr.ih_magic != IMAGE_MAGIC ||
+ boot_image_check(&boot_data.imgs[1].hdr, fap) != 0) {
+
+ /* Image in slot 1 is invalid. Erase the image and continue booting
+ * from slot 0.
+ */
+ flash_area_erase(fap, 0, fap->fa_size);
+ return -1;
+ }
+
+ flash_area_close(fap);
+
+ /* Image in slot 1 is valid. */
+ return 0;
+}
+
+/**
+ * Determines which swap operation to perform, if any. If it is determined
+ * that a swap operation is required, the image in the second slot is checked
+ * for validity. If the image in the second 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(void)
+{
+ int swap_type;
+ int rc;
+
+ swap_type = boot_swap_type();
+ if (swap_type == BOOT_SWAP_TYPE_NONE) {
+ /* Continue using slot 0. */
+ return BOOT_SWAP_TYPE_NONE;
+ }
+
+ /* Boot loader wants to switch to slot 1. Ensure image is valid. */
+ rc = boot_validate_slot1();
+ if (rc != 0) {
+ return 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.
+ */
+static uint32_t
+boot_copy_sz(int last_sector_idx, int *out_first_sector_idx)
+{
+ uint32_t new_sz;
+ uint32_t sz;
+ int i;
+
+ sz = 0;
+
+ for (i = last_sector_idx; i >= 0; i--) {
+ new_sz = sz + boot_data.imgs[0].sectors[i].fa_size;
+ if (new_sz > boot_data.scratch_sector.fa_size) {
+ 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;
+}
+
+/**
+ * Erases a region of flash.
+ *
+ * @param flash_area_idx The ID of 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 int
+boot_erase_sector(int flash_area_id, uint32_t off, uint32_t sz)
+{
+ const struct flash_area *fap;
+ int rc;
+
+ rc = flash_area_open(flash_area_id, &fap);
+ if (rc != 0) {
+ rc = BOOT_EFLASH;
+ goto done;
+ }
+
+ rc = flash_area_erase(fap, off, sz);
+ if (rc != 0) {
+ rc = BOOT_EFLASH;
+ goto done;
+ }
+
+ rc = 0;
+
+done:
+ flash_area_close(fap);
+ return rc;
+}
+
+/**
+ * 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(int flash_area_id_src, int flash_area_id_dst,
+ uint32_t off_src, uint32_t off_dst, uint32_t sz)
+{
+ const struct flash_area *fap_src;
+ const struct flash_area *fap_dst;
+ uint32_t bytes_copied;
+ int chunk_sz;
+ int rc;
+
+ static uint8_t buf[1024];
+
+ fap_src = NULL;
+ fap_dst = NULL;
+
+ rc = flash_area_open(flash_area_id_src, &fap_src);
+ if (rc != 0) {
+ rc = BOOT_EFLASH;
+ goto done;
+ }
+
+ rc = flash_area_open(flash_area_id_dst, &fap_dst);
+ if (rc != 0) {
+ rc = BOOT_EFLASH;
+ goto done;
+ }
+
+ 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) {
+ rc = BOOT_EFLASH;
+ goto done;
+ }
+
+ rc = flash_area_write(fap_dst, off_dst + bytes_copied, buf, chunk_sz);
+ if (rc != 0) {
+ rc = BOOT_EFLASH;
+ goto done;
+ }
+
+ bytes_copied += chunk_sz;
+ }
+
+ rc = 0;
+
+done:
+ flash_area_close(fap_src);
+ flash_area_close(fap_dst);
+ return rc;
+}
+
+/**
+ * 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.
+ */
+static int
+boot_swap_sectors(int idx, uint32_t sz, struct boot_status *bs)
+{
+ uint32_t copy_sz;
+ uint32_t img_off;
+ int rc;
+
+ /* Calculate offset from start of image area. */
+ img_off = boot_data.imgs[0].sectors[idx].fa_off -
+ boot_data.imgs[0].sectors[0].fa_off;
+
+ if (bs->state == 0) {
+ rc = boot_erase_sector(FLASH_AREA_IMAGE_SCRATCH, 0, sz);
+ if (rc != 0) {
+ return rc;
+ }
+
+ rc = boot_copy_sector(FLASH_AREA_IMAGE_1, FLASH_AREA_IMAGE_SCRATCH,
+ img_off, 0, sz);
+ if (rc != 0) {
+ return rc;
+ }
+
+ bs->state = 1;
+ (void)boot_write_status(bs);
+ }
+ if (bs->state == 1) {
+ rc = boot_erase_sector(FLASH_AREA_IMAGE_1, img_off, sz);
+ if (rc != 0) {
+ return rc;
+ }
+
+ copy_sz = sz;
+ if (boot_data.imgs[0].sectors[idx].fa_off + sz >=
+ boot_data.imgs[1].sectors[0].fa_off) {
+
+ /* This is the end of the area. Don't copy the image state into
+ * slot 1.
+ */
+ copy_sz -= boot_trailer_sz(boot_data.write_sz);
+ }
+
+ rc = boot_copy_sector(FLASH_AREA_IMAGE_0, FLASH_AREA_IMAGE_1,
+ img_off, img_off, copy_sz);
+ if (rc != 0) {
+ return rc;
+ }
+
+ bs->state = 2;
+ (void)boot_write_status(bs);
+ }
+ if (bs->state == 2) {
+ rc = boot_erase_sector(FLASH_AREA_IMAGE_0, img_off, sz);
+ if (rc != 0) {
+ return rc;
+ }
+
+ rc = boot_copy_sector(FLASH_AREA_IMAGE_SCRATCH, FLASH_AREA_IMAGE_0,
+ 0, img_off, sz);
+ if (rc != 0) {
+ return rc;
+ }
+
+ bs->idx++;
+ bs->state = 0;
+ (void)boot_write_status(bs);
+ }
+
+ return 0;
+}
+
+/**
+ * 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_copy_image(struct boot_status *bs)
+{
+ uint32_t sz;
+ int first_sector_idx;
+ int last_sector_idx;
+ int swap_idx;
+
+ swap_idx = 0;
+ last_sector_idx = boot_data.num_img_sectors - 1;
+ while (last_sector_idx >= 0) {
+ sz = boot_copy_sz(last_sector_idx, &first_sector_idx);
+ if (swap_idx >= bs->idx) {
+ boot_swap_sectors(first_sector_idx, sz, bs);
+ }
+
+ last_sector_idx = first_sector_idx - 1;
+ swap_idx++;
+ }
+
+ return 0;
+}
+
+/**
+ * Marks a test image in slot 0 as fully copied.
+ */
+static int
+boot_finalize_test_swap(void)
+{
+ const struct flash_area *fap;
+ int rc;
+
+ rc = flash_area_open(FLASH_AREA_IMAGE_0, &fap);
+ if (rc != 0) {
+ return BOOT_EFLASH;
+ }
+
+ rc = boot_write_copy_done(fap);
+ if (rc != 0) {
+ return rc;
+ }
+
+ return 0;
+}
+
+/**
+ * Marks a reverted image in slot 0 as confirmed. This is necessary to ensure
+ * the status bytes from the image revert operation don't get processed on a
+ * subsequent boot.
+ */
+static int
+boot_finalize_revert_swap(void)
+{
+ const struct flash_area *fap;
+ struct boot_swap_state state_slot0;
+ int rc;
+
+ rc = flash_area_open(FLASH_AREA_IMAGE_0, &fap);
+ if (rc != 0) {
+ return BOOT_EFLASH;
+ }
+
+ rc = boot_read_swap_state(fap, &state_slot0);
+ if (rc != 0) {
+ return BOOT_EFLASH;
+ }
+
+ if (state_slot0.magic == BOOT_MAGIC_UNSET) {
+ rc = boot_write_magic(fap);
+ if (rc != 0) {
+ return rc;
+ }
+ }
+
+ if (state_slot0.copy_done == 0xff) {
+ rc = boot_write_copy_done(fap);
+ if (rc != 0) {
+ return rc;
+ }
+ }
+
+ if (state_slot0.image_ok == 0xff) {
+ rc = boot_write_image_ok(fap);
+ if (rc != 0) {
+ return rc;
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * 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)
+{
+ struct boot_status bs;
+ int swap_type;
+ int slot;
+ int rc;
+
+ /* 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 for some reason.
+ */
+ static struct flash_area slot0_sectors[BOOT_MAX_IMG_SECTORS];
+ static struct flash_area slot1_sectors[BOOT_MAX_IMG_SECTORS];
+ boot_data.imgs[0].sectors = slot0_sectors;
+ boot_data.imgs[1].sectors = slot1_sectors;
+
+ /* Determine the sector layout of the image slots and scratch area. */
+ rc = boot_read_sectors();
+ if (rc != 0) {
+ return rc;
+ }
+
+ /* Attempt to read an image header from each slot. */
+ rc = boot_read_image_headers();
+ if (rc != 0) {
+ return rc;
+ }
+
+ /* Determine if we rebooted in the middle of an image swap operation. */
+ rc = boot_read_status(&bs);
+ if (rc != 0) {
+ return rc;
+ }
+
+ /* If a partial swap was detected, complete it. */
+ if (bs.idx != 0 || bs.state != 0) {
+ rc = boot_copy_image(&bs);
+ assert(rc == 0);
+
+ /* Extrapolate the type of the partial swap. We need this information
+ * to know how to mark the swap complete in flash.
+ */
+ swap_type = boot_previous_swap_type();
+ } else {
+ swap_type = boot_validated_swap_type();
+ switch (swap_type) {
+ case BOOT_SWAP_TYPE_TEST:
+ case BOOT_SWAP_TYPE_REVERT:
+ rc = boot_copy_image(&bs);
+ assert(rc == 0);
+ break;
+ }
+ }
+
+ switch (swap_type) {
+ case BOOT_SWAP_TYPE_NONE:
+ slot = 0;
+ break;
+
+ case BOOT_SWAP_TYPE_TEST:
+ slot = 1;
+ boot_finalize_test_swap();
+ break;
+
+ case BOOT_SWAP_TYPE_REVERT:
+ slot = 1;
+ boot_finalize_revert_swap();
+ break;
+
+ case BOOT_SWAP_TYPE_FAIL:
+ /* The image in slot 1 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 slot 0.
+ */
+ slot = 0;
+ boot_finalize_revert_swap();
+ break;
+
+ default:
+ assert(0);
+ slot = 0;
+ break;
+ }
+
+ /* Always boot from the primary slot. */
+ rsp->br_flash_id = boot_data.imgs[0].sectors[0].fa_device_id;
+ rsp->br_image_addr = boot_data.imgs[0].sectors[0].fa_off;
+ rsp->br_hdr = &boot_data.imgs[slot].hdr;
+
+ return 0;
+}
+
+int
+split_go(int loader_slot, int split_slot, void **entry)
+{
+ const struct flash_area *loader_fap;
+ const struct flash_area *app_fap;
+ struct flash_area *sectors;
+ uint32_t entry_val;
+ int loader_flash_id;
+ int app_flash_id;
+ int rc;
+
+ app_fap = NULL;
+ loader_fap = NULL;
+
+ sectors = malloc(BOOT_MAX_IMG_SECTORS * 2 * sizeof *sectors);
+ if (sectors == NULL) {
+ rc = SPLIT_GO_ERR;
+ goto done;
+ }
+ boot_data.imgs[0].sectors = sectors + 0;
+ boot_data.imgs[1].sectors = sectors + BOOT_MAX_IMG_SECTORS;
+
+ /* Determine the sector layout of the image slots and scratch area. */
+ rc = boot_read_sectors();
+ if (rc != 0) {
+ rc = SPLIT_GO_ERR;
+ goto done;
+ }
+
+ rc = boot_read_image_headers();
+ if (rc != 0) {
+ goto done;
+ }
+
+ app_flash_id = flash_area_id_from_image_slot(split_slot);
+ rc = flash_area_open(app_flash_id, &app_fap);
+ if (rc != 0) {
+ rc = BOOT_EFLASH;
+ goto done;
+ }
+
+ loader_flash_id = flash_area_id_from_image_slot(loader_slot);
+ rc = flash_area_open(loader_flash_id, &loader_fap);
+ if (rc != 0) {
+ rc = BOOT_EFLASH;
+ 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_data.imgs[split_slot].hdr,
+ app_fap,
+ &boot_data.imgs[loader_slot].hdr,
+ loader_fap);
+ if (rc != 0) {
+ rc = SPLIT_GO_NON_MATCHING;
+ goto done;
+ }
+
+ entry_val = boot_data.imgs[split_slot].sectors[0].fa_off +
+ boot_data.imgs[split_slot].hdr.ih_hdr_size;
+ *entry = (void*) entry_val;
+ rc = SPLIT_GO_OK;
+
+done:
+ free(sectors);
+ flash_area_close(app_fap);
+ flash_area_close(loader_fap);
+ return rc;
+}