zephyr/subsys/dfu/boot/mcuboot.c

508 lines
11 KiB
C

/*
* Copyright (c) 2017 Nordic Semiconductor ASA
* Copyright (c) 2016-2017 Linaro Limited
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <assert.h>
#include <stddef.h>
#include <errno.h>
#include <string.h>
#include <flash.h>
#include <flash_map.h>
#include <zephyr.h>
#include <init.h>
#include <misc/__assert.h>
#include <misc/byteorder.h>
#include <dfu/mcuboot.h>
/*
* Helpers for image headers and trailers, as defined by mcuboot.
*/
/*
* Strict defines: the definitions in the following block contain
* values which are MCUboot implementation requirements.
*/
/* Header: */
#define BOOT_HEADER_MAGIC_V1 0x96f3b83d
#define BOOT_HEADER_SIZE_V1 32
/* Trailer: */
#define BOOT_MAX_ALIGN 8
#define BOOT_MAGIC_SZ 16
#define BOOT_FLAG_SET 0x01
#define BOOT_FLAG_UNSET 0xff
/*
* Raw (on-flash) representation of the v1 image header.
*/
struct mcuboot_v1_raw_header {
u32_t header_magic;
u32_t image_load_address;
u16_t header_size;
u16_t pad;
u32_t image_size;
u32_t image_flags;
struct {
u8_t major;
u8_t minor;
u16_t revision;
u32_t build_num;
} version;
u32_t pad2;
} __packed;
/*
* End of strict defines
*/
#define BOOT_MAGIC_GOOD 1
#define BOOT_MAGIC_BAD 2
#define BOOT_MAGIC_UNSET 3
#define BOOT_FLAG_IMAGE_OK 0
#define BOOT_FLAG_COPY_DONE 1
#define FLASH_MIN_WRITE_SIZE DT_FLASH_WRITE_BLOCK_SIZE
/* DT_FLASH_AREA_IMAGE_XX_YY values used below are auto-generated by DT */
#define FLASH_BANK0_ID DT_FLASH_AREA_IMAGE_0_ID
#define FLASH_BANK1_ID DT_FLASH_AREA_IMAGE_1_ID
#define COPY_DONE_OFFS(bank_area) ((bank_area)->fa_size -\
BOOT_MAGIC_SZ - BOOT_MAX_ALIGN * 2)
#define IMAGE_OK_OFFS(bank_area) ((bank_area)->fa_size - BOOT_MAGIC_SZ -\
BOOT_MAX_ALIGN)
#define MAGIC_OFFS(bank_area) ((bank_area)->fa_size - BOOT_MAGIC_SZ)
static const u32_t boot_img_magic[4] = {
0xf395c277,
0x7fefd260,
0x0f505235,
0x8079b62c,
};
struct boot_swap_table {
/** For each field, a value of 0 means "any". */
u8_t magic_slot0;
u8_t magic_slot1;
u8_t image_ok_slot0;
u8_t image_ok_slot1;
u8_t copy_done_slot0;
u8_t swap_type;
};
/** Represents the management state of a single image slot. */
struct boot_swap_state {
u8_t magic; /* One of the BOOT_MAGIC_[...] values. */
u8_t copy_done;
u8_t image_ok;
};
/**
* This set of tables maps image trailer contents to swap operation type.
* When searching for a match, these tables must be iterated sequentially.
*/
static const struct boot_swap_table boot_swap_tables[] = {
{
/* | slot-0 | slot-1 |
*----------+------------+------------|
* magic | Any | Good |
* image-ok | Any | Unset |
* ---------+------------+------------+
* swap: test |
* -----------------------------------'
*/
.magic_slot0 = 0,
.magic_slot1 = BOOT_MAGIC_GOOD,
.image_ok_slot0 = 0,
.image_ok_slot1 = 0xff,
.copy_done_slot0 = 0,
.swap_type = BOOT_SWAP_TYPE_TEST,
},
{
/* | slot-0 | slot-1 |
*----------+------------+------------|
* magic | Any | Good |
* image-ok | Any | 0x01 |
* ---------+------------+------------+
* swap: permanent |
* -----------------------------------'
*/
.magic_slot0 = 0,
.magic_slot1 = BOOT_MAGIC_GOOD,
.image_ok_slot0 = 0,
.image_ok_slot1 = 0x01,
.copy_done_slot0 = 0,
.swap_type = BOOT_SWAP_TYPE_PERM,
},
{
/* | slot-0 | slot-1 |
*----------+------------+------------|
* magic | Good | Unset |
* image-ok | Unset | Any |
* ---------+------------+------------+
* swap: revert (test image running) |
* -----------------------------------'
*/
.magic_slot0 = BOOT_MAGIC_GOOD,
.magic_slot1 = BOOT_MAGIC_UNSET,
.image_ok_slot0 = 0xff,
.image_ok_slot1 = 0,
.copy_done_slot0 = 0x01,
.swap_type = BOOT_SWAP_TYPE_REVERT,
},
};
#define BOOT_SWAP_TABLES_COUNT (ARRAY_SIZE(boot_swap_tables))
static int boot_flag_offs(int flag, const struct flash_area *fa, u32_t *offs)
{
switch (flag) {
case BOOT_FLAG_COPY_DONE:
*offs = COPY_DONE_OFFS(fa);
return 0;
case BOOT_FLAG_IMAGE_OK:
*offs = IMAGE_OK_OFFS(fa);
return 0;
default:
return -ENOTSUP;
}
}
static int boot_flag_write(int flag, u8_t bank_id)
{
const struct flash_area *fa;
u8_t buf[FLASH_MIN_WRITE_SIZE];
u32_t offs;
int rc;
rc = flash_area_open(bank_id, &fa);
if (rc) {
return rc;
}
rc = boot_flag_offs(flag, fa, &offs);
if (rc != 0) {
flash_area_close(fa);
return rc;
}
(void)memset(buf, BOOT_FLAG_UNSET, sizeof(buf));
buf[0] = BOOT_FLAG_SET;
rc = flash_area_write(fa, offs, buf, sizeof(buf));
flash_area_close(fa);
return rc;
}
static int boot_flag_read(int flag, u8_t bank_id)
{
const struct flash_area *fa;
u32_t offs;
int rc;
u8_t flag_val;
rc = flash_area_open(bank_id, &fa);
if (rc) {
return rc;
}
rc = boot_flag_offs(flag, fa, &offs);
if (rc != 0) {
flash_area_close(fa);
return rc;
}
rc = flash_area_read(fa, offs, &flag_val, sizeof(flag_val));
if (rc != 0) {
return rc;
}
return flag_val;
}
static int boot_image_ok_read(u8_t bank_id)
{
return boot_flag_read(BOOT_FLAG_IMAGE_OK, bank_id);
}
static int boot_image_ok_write(u8_t bank_id)
{
return boot_flag_write(BOOT_FLAG_IMAGE_OK, bank_id);
}
static int boot_copy_done_read(u8_t bank_id)
{
return boot_flag_read(BOOT_FLAG_COPY_DONE, bank_id);
}
static int boot_magic_write(u8_t bank_id)
{
const struct flash_area *fa;
u32_t offs;
int rc;
rc = flash_area_open(bank_id, &fa);
if (rc) {
return rc;
}
offs = MAGIC_OFFS(fa);
rc = flash_area_write(fa, offs, boot_img_magic, BOOT_MAGIC_SZ);
flash_area_close(fa);
return rc;
}
static int boot_read_v1_header(u8_t area_id,
struct mcuboot_v1_raw_header *v1_raw)
{
const struct flash_area *fa;
int rc;
rc = flash_area_open(area_id, &fa);
if (rc) {
return rc;
}
/*
* Read and sanity-check the raw header.
*/
rc = flash_area_read(fa, 0, v1_raw, sizeof(*v1_raw));
flash_area_close(fa);
if (rc) {
return rc;
}
v1_raw->header_magic = sys_le32_to_cpu(v1_raw->header_magic);
v1_raw->image_load_address =
sys_le32_to_cpu(v1_raw->image_load_address);
v1_raw->header_size = sys_le16_to_cpu(v1_raw->header_size);
v1_raw->image_size = sys_le32_to_cpu(v1_raw->image_size);
v1_raw->image_flags = sys_le32_to_cpu(v1_raw->image_flags);
v1_raw->version.revision =
sys_le16_to_cpu(v1_raw->version.revision);
v1_raw->version.build_num =
sys_le32_to_cpu(v1_raw->version.build_num);
/*
* Sanity checks.
*
* Larger values in header_size than BOOT_HEADER_SIZE_V1 are
* possible, e.g. if Zephyr was linked with
* CONFIG_TEXT_SECTION_OFFSET > BOOT_HEADER_SIZE_V1.
*/
if ((v1_raw->header_magic != BOOT_HEADER_MAGIC_V1) ||
(v1_raw->header_size < BOOT_HEADER_SIZE_V1)) {
return -EIO;
}
return 0;
}
int boot_read_bank_header(u8_t area_id,
struct mcuboot_img_header *header,
size_t header_size)
{
int rc;
struct mcuboot_v1_raw_header v1_raw;
struct mcuboot_img_sem_ver *sem_ver;
size_t v1_min_size = (sizeof(u32_t) +
sizeof(struct mcuboot_img_header_v1));
/*
* Only version 1 image headers are supported.
*/
if (header_size < v1_min_size) {
return -ENOMEM;
}
rc = boot_read_v1_header(area_id, &v1_raw);
if (rc) {
return rc;
}
/*
* Copy just the fields we care about into the return parameter.
*
* - header_magic: skip (only used to check format)
* - image_load_address: skip (only matters for PIC code)
* - header_size: skip (only used to check format)
* - image_size: include
* - image_flags: skip (all unsupported or not relevant)
* - version: include
*/
header->mcuboot_version = 1;
header->h.v1.image_size = v1_raw.image_size;
sem_ver = &header->h.v1.sem_ver;
sem_ver->major = v1_raw.version.major;
sem_ver->minor = v1_raw.version.minor;
sem_ver->revision = v1_raw.version.revision;
sem_ver->build_num = v1_raw.version.build_num;
return 0;
}
static int boot_magic_code_check(const u32_t *magic)
{
int i;
if (memcmp(magic, boot_img_magic, sizeof(boot_img_magic)) == 0) {
return BOOT_MAGIC_GOOD;
}
for (i = 0; i < ARRAY_SIZE(boot_img_magic); i++) {
if (magic[i] != 0xffffffff) {
return BOOT_MAGIC_BAD;
}
}
return BOOT_MAGIC_UNSET;
}
static int boot_magic_state_read(u8_t bank_id)
{
const struct flash_area *fa;
u32_t magic[(sizeof(u32_t) - 1 + BOOT_MAGIC_SZ) / sizeof(u32_t)];
u32_t offs;
int rc;
rc = flash_area_open(bank_id, &fa);
if (rc) {
return rc;
}
offs = MAGIC_OFFS(fa);
rc = flash_area_read(fa, offs, magic, BOOT_MAGIC_SZ);
flash_area_close(fa);
if (rc != 0) {
return rc;
}
return boot_magic_code_check(magic);
}
static int boot_read_swap_state(u8_t bank_id, struct boot_swap_state *state)
{
int rc;
rc = boot_magic_state_read(bank_id);
if (rc < 0) {
return rc;
}
state->magic = rc;
if (bank_id != DT_FLASH_AREA_IMAGE_SCRATCH_ID) {
rc = boot_copy_done_read(bank_id);
if (rc < 0) {
return rc;
}
state->copy_done = rc;
}
rc = boot_image_ok_read(bank_id);
if (rc < 0) {
return rc;
}
state->image_ok = rc;
return 0;
}
int mcuboot_swap_type(void)
{
const struct boot_swap_table *table;
struct boot_swap_state state_slot0;
struct boot_swap_state state_slot1;
int rc;
int i;
rc = boot_read_swap_state(FLASH_BANK0_ID, &state_slot0);
if (rc != 0) {
return rc;
}
rc = boot_read_swap_state(FLASH_BANK1_ID, &state_slot1);
if (rc != 0) {
return rc;
}
for (i = 0; i < BOOT_SWAP_TABLES_COUNT; i++) {
table = boot_swap_tables + i;
if ((table->magic_slot0 == 0 ||
table->magic_slot0 == state_slot0.magic) &&
(table->magic_slot1 == 0 ||
table->magic_slot1 == state_slot1.magic) &&
(table->image_ok_slot0 == 0 ||
table->image_ok_slot0 == state_slot0.image_ok) &&
(table->image_ok_slot1 == 0 ||
table->image_ok_slot1 == state_slot1.image_ok) &&
(table->copy_done_slot0 == 0 ||
table->copy_done_slot0 == state_slot0.copy_done)) {
assert(table->swap_type == BOOT_SWAP_TYPE_TEST ||
table->swap_type == BOOT_SWAP_TYPE_PERM ||
table->swap_type == BOOT_SWAP_TYPE_REVERT);
return table->swap_type;
}
}
return BOOT_SWAP_TYPE_NONE;
}
int boot_request_upgrade(int permanent)
{
int rc;
rc = boot_magic_write(FLASH_BANK1_ID);
if (rc == 0 && permanent) {
rc = boot_image_ok_write(FLASH_BANK1_ID);
}
return rc;
}
bool boot_is_img_confirmed(void)
{
return boot_image_ok_read(FLASH_BANK0_ID) == BOOT_FLAG_SET;
}
int boot_write_img_confirmed(void)
{
int rc;
if (boot_image_ok_read(FLASH_BANK0_ID) != BOOT_FLAG_UNSET) {
/* Already confirmed. */
return 0;
}
rc = boot_image_ok_write(FLASH_BANK0_ID);
return rc;
}
int boot_erase_img_bank(u8_t area_id)
{
const struct flash_area *fa;
int rc;
rc = flash_area_open(area_id, &fa);
if (rc) {
return rc;
}
rc = flash_area_erase(fa, 0, fa->fa_size);
flash_area_close(fa);
return rc;
}