Merge branch 'feature/add_doc_about_app_desc_t' into 'master'

docs: Add description about the app image

Closes IDF-597

See merge request idf/esp-idf!4912
This commit is contained in:
Angus Gratton 2019-06-24 18:40:02 +08:00
commit 5cb71b5213
7 changed files with 223 additions and 85 deletions

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// Copyright 2015-2019 Espressif Systems (Shanghai) PTE LTD
//
// Licensed 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.
#pragma once
/**
* @brief SPI flash mode, used in esp_image_header_t
*/
typedef enum {
ESP_IMAGE_SPI_MODE_QIO, /*!< SPI mode QIO */
ESP_IMAGE_SPI_MODE_QOUT, /*!< SPI mode QOUT */
ESP_IMAGE_SPI_MODE_DIO, /*!< SPI mode DIO */
ESP_IMAGE_SPI_MODE_DOUT, /*!< SPI mode DOUT */
ESP_IMAGE_SPI_MODE_FAST_READ, /*!< SPI mode FAST_READ */
ESP_IMAGE_SPI_MODE_SLOW_READ /*!< SPI mode SLOW_READ */
} esp_image_spi_mode_t;
/**
* @brief SPI flash clock frequency
*/
typedef enum {
ESP_IMAGE_SPI_SPEED_40M, /*!< SPI clock frequency 40 MHz */
ESP_IMAGE_SPI_SPEED_26M, /*!< SPI clock frequency 26 MHz */
ESP_IMAGE_SPI_SPEED_20M, /*!< SPI clock frequency 20 MHz */
ESP_IMAGE_SPI_SPEED_80M = 0xF /*!< SPI clock frequency 80 MHz */
} esp_image_spi_freq_t;
/**
* @brief Supported SPI flash sizes
*/
typedef enum {
ESP_IMAGE_FLASH_SIZE_1MB = 0, /*!< SPI flash size 1 MB */
ESP_IMAGE_FLASH_SIZE_2MB, /*!< SPI flash size 2 MB */
ESP_IMAGE_FLASH_SIZE_4MB, /*!< SPI flash size 4 MB */
ESP_IMAGE_FLASH_SIZE_8MB, /*!< SPI flash size 8 MB */
ESP_IMAGE_FLASH_SIZE_16MB, /*!< SPI flash size 16 MB */
ESP_IMAGE_FLASH_SIZE_MAX /*!< SPI flash size MAX */
} esp_image_flash_size_t;
#define ESP_IMAGE_HEADER_MAGIC 0xE9 /*!< The magic word for the esp_image_header_t structure. */
/**
* @brief Main header of binary image
*/
typedef struct {
uint8_t magic; /*!< Magic word ESP_IMAGE_HEADER_MAGIC */
uint8_t segment_count; /*!< Count of memory segments */
uint8_t spi_mode; /*!< flash read mode (esp_image_spi_mode_t as uint8_t) */
uint8_t spi_speed: 4; /*!< flash frequency (esp_image_spi_freq_t as uint8_t) */
uint8_t spi_size: 4; /*!< flash chip size (esp_image_flash_size_t as uint8_t) */
uint32_t entry_addr; /*!< Entry address */
uint8_t wp_pin; /*!< WP pin when SPI pins set via efuse (read by ROM bootloader,
* the IDF bootloader uses software to configure the WP
* pin and sets this field to 0xEE=disabled) */
uint8_t spi_pin_drv[3]; /*!< Drive settings for the SPI flash pins (read by ROM bootloader) */
uint8_t reserved[11]; /*!< Reserved bytes in ESP32 additional header space, currently unused */
uint8_t hash_appended; /*!< If 1, a SHA256 digest "simple hash" (of the entire image) is appended after the checksum.
* Included in image length. This digest
* is separate to secure boot and only used for detecting corruption.
* For secure boot signed images, the signature
* is appended after this (and the simple hash is included in the signed data). */
} __attribute__((packed)) esp_image_header_t;
/** @cond */
_Static_assert(sizeof(esp_image_header_t) == 24, "binary image header should be 24 bytes");
/** @endcond */
/**
* @brief Header of binary image segment
*/
typedef struct {
uint32_t load_addr; /*!< Address of segment */
uint32_t data_len; /*!< Length of data */
} esp_image_segment_header_t;
#define ESP_IMAGE_MAX_SEGMENTS 16 /*!< Max count of segments in the image. */
#define ESP_APP_DESC_MAGIC_WORD 0xABCD5432 /*!< The magic word for the esp_app_desc structure that is in DROM. */
/**
* @brief Description about application.
*/
typedef struct {
uint32_t magic_word; /*!< Magic word ESP_APP_DESC_MAGIC_WORD */
uint32_t secure_version; /*!< Secure version */
uint32_t reserv1[2]; /*!< reserv1 */
char version[32]; /*!< Application version */
char project_name[32]; /*!< Project name */
char time[16]; /*!< Compile time */
char date[16]; /*!< Compile date*/
char idf_ver[32]; /*!< Version IDF */
uint8_t app_elf_sha256[32]; /*!< sha256 of elf file */
uint32_t reserv2[20]; /*!< reserv2 */
} esp_app_desc_t;
/** @cond */
_Static_assert(sizeof(esp_app_desc_t) == 256, "esp_app_desc_t should be 256 bytes");
/** @endcond */

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@ -16,6 +16,7 @@
#include <stdbool.h>
#include <esp_err.h>
#include "esp_flash_partitions.h"
#include "esp_app_format.h"
#define ESP_ERR_IMAGE_BASE 0x2000
#define ESP_ERR_IMAGE_FLASH_FAIL (ESP_ERR_IMAGE_BASE + 1)
@ -25,91 +26,8 @@
Can be compiled as part of app or bootloader code.
*/
/* SPI flash mode, used in esp_image_header_t */
typedef enum {
ESP_IMAGE_SPI_MODE_QIO,
ESP_IMAGE_SPI_MODE_QOUT,
ESP_IMAGE_SPI_MODE_DIO,
ESP_IMAGE_SPI_MODE_DOUT,
ESP_IMAGE_SPI_MODE_FAST_READ,
ESP_IMAGE_SPI_MODE_SLOW_READ
} esp_image_spi_mode_t;
/* SPI flash clock frequency */
typedef enum {
ESP_IMAGE_SPI_SPEED_40M,
ESP_IMAGE_SPI_SPEED_26M,
ESP_IMAGE_SPI_SPEED_20M,
ESP_IMAGE_SPI_SPEED_80M = 0xF
} esp_image_spi_freq_t;
/* Supported SPI flash sizes */
typedef enum {
ESP_IMAGE_FLASH_SIZE_1MB = 0,
ESP_IMAGE_FLASH_SIZE_2MB,
ESP_IMAGE_FLASH_SIZE_4MB,
ESP_IMAGE_FLASH_SIZE_8MB,
ESP_IMAGE_FLASH_SIZE_16MB,
ESP_IMAGE_FLASH_SIZE_MAX
} esp_image_flash_size_t;
#define ESP_IMAGE_HEADER_MAGIC 0xE9
/* Main header of binary image */
typedef struct {
uint8_t magic;
uint8_t segment_count;
/* flash read mode (esp_image_spi_mode_t as uint8_t) */
uint8_t spi_mode;
/* flash frequency (esp_image_spi_freq_t as uint8_t) */
uint8_t spi_speed: 4;
/* flash chip size (esp_image_flash_size_t as uint8_t) */
uint8_t spi_size: 4;
uint32_t entry_addr;
/* WP pin when SPI pins set via efuse (read by ROM bootloader, the IDF bootloader uses software to configure the WP
* pin and sets this field to 0xEE=disabled) */
uint8_t wp_pin;
/* Drive settings for the SPI flash pins (read by ROM bootloader) */
uint8_t spi_pin_drv[3];
/* Reserved bytes in ESP32 additional header space, currently unused */
uint8_t reserved[11];
/* If 1, a SHA256 digest "simple hash" (of the entire image) is appended after the checksum. Included in image length. This digest
* is separate to secure boot and only used for detecting corruption. For secure boot signed images, the signature
* is appended after this (and the simple hash is included in the signed data). */
uint8_t hash_appended;
} __attribute__((packed)) esp_image_header_t;
_Static_assert(sizeof(esp_image_header_t) == 24, "binary image header should be 24 bytes");
#define ESP_IMAGE_HASH_LEN 32 /* Length of the appended SHA-256 digest */
/* Header of binary image segment */
typedef struct {
uint32_t load_addr;
uint32_t data_len;
} esp_image_segment_header_t;
#define ESP_APP_DESC_MAGIC_WORD 0xABCD5432 /*!< The magic word for the esp_app_desc structure that is in DROM. */
/**
* @brief Description about application.
*/
typedef struct {
uint32_t magic_word; /*!< Magic word ESP_APP_DESC_MAGIC_WORD */
uint32_t secure_version; /*!< Secure version */
uint32_t reserv1[2]; /*!< --- */
char version[32]; /*!< Application version */
char project_name[32]; /*!< Project name */
char time[16]; /*!< Compile time */
char date[16]; /*!< Compile date*/
char idf_ver[32]; /*!< Version IDF */
uint8_t app_elf_sha256[32]; /*!< sha256 of elf file */
uint32_t reserv2[20]; /*!< --- */
} esp_app_desc_t;
_Static_assert(sizeof(esp_app_desc_t) == 256, "esp_app_desc_t should be 256 bytes");
#define ESP_IMAGE_MAX_SEGMENTS 16
/* Structure to hold on-flash image metadata */
typedef struct {
uint32_t start_addr; /* Start address of image */

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@ -208,6 +208,8 @@ INPUT = \
../../components/esp_event/include/esp_event_base.h \
### eFuse Manager
../../components/efuse/include/esp_efuse.h \
### App Image Format
../../components/bootloader_support/include/esp_app_format.h \
### ESP Pthread parameters
../../components/pthread/include/esp_pthread.h \
###

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App Image Format
================
An application image consists of the following structures:
1. The :cpp:type:`esp_image_header_t` structure describes the mode of SPI flash and the count of memory segments.
2. The :cpp:type:`esp_image_segment_header_t` structure describes each segment, its length, and its location in ESP32's memory, followed by the data with a length of ``data_len``. The data offset for each segment in the image is calculated in the following way:
* offset for 0 Segment = sizeof(:cpp:type:`esp_image_header_t`) + sizeof(:cpp:type:`esp_image_segment_header_t`).
* offset for 1 Segment = offset for 0 Segment + length of 0 Segment + sizeof(:cpp:type:`esp_image_segment_header_t`).
* offset for 2 Segment = offset for 1 Segment + length of 1 Segment + sizeof(:cpp:type:`esp_image_segment_header_t`).
* ...
The count of each segment is defined in the ``segment_count`` field that is stored in :cpp:type:`esp_image_header_t`. The count cannot be more than :cpp:type:`ESP_IMAGE_MAX_SEGMENTS`.
To get the list of your image segments, please run the following command:
::
esptool.py --chip esp32 image_info build/app.bin
::
esptool.py v2.3.1
Image version: 1
Entry point: 40080ea4
13 segments
Segment 1: len 0x13ce0 load 0x3f400020 file_offs 0x00000018 SOC_DROM
Segment 2: len 0x00000 load 0x3ff80000 file_offs 0x00013d00 SOC_RTC_DRAM
Segment 3: len 0x00000 load 0x3ff80000 file_offs 0x00013d08 SOC_RTC_DRAM
Segment 4: len 0x028e0 load 0x3ffb0000 file_offs 0x00013d10 DRAM
Segment 5: len 0x00000 load 0x3ffb28e0 file_offs 0x000165f8 DRAM
Segment 6: len 0x00400 load 0x40080000 file_offs 0x00016600 SOC_IRAM
Segment 7: len 0x09600 load 0x40080400 file_offs 0x00016a08 SOC_IRAM
Segment 8: len 0x62e4c load 0x400d0018 file_offs 0x00020010 SOC_IROM
Segment 9: len 0x06cec load 0x40089a00 file_offs 0x00082e64 SOC_IROM
Segment 10: len 0x00000 load 0x400c0000 file_offs 0x00089b58 SOC_RTC_IRAM
Segment 11: len 0x00004 load 0x50000000 file_offs 0x00089b60 SOC_RTC_DATA
Segment 12: len 0x00000 load 0x50000004 file_offs 0x00089b6c SOC_RTC_DATA
Segment 13: len 0x00000 load 0x50000004 file_offs 0x00089b74 SOC_RTC_DATA
Checksum: e8 (valid)Validation Hash: 407089ca0eae2bbf83b4120979d3354b1c938a49cb7a0c997f240474ef2ec76b (valid)
You can also see the information on segments in the IDF logs while your application is booting:
::
I (443) esp_image: segment 0: paddr=0x00020020 vaddr=0x3f400020 size=0x13ce0 ( 81120) map
I (489) esp_image: segment 1: paddr=0x00033d08 vaddr=0x3ff80000 size=0x00000 ( 0) load
I (530) esp_image: segment 2: paddr=0x00033d10 vaddr=0x3ff80000 size=0x00000 ( 0) load
I (571) esp_image: segment 3: paddr=0x00033d18 vaddr=0x3ffb0000 size=0x028e0 ( 10464) load
I (612) esp_image: segment 4: paddr=0x00036600 vaddr=0x3ffb28e0 size=0x00000 ( 0) load
I (654) esp_image: segment 5: paddr=0x00036608 vaddr=0x40080000 size=0x00400 ( 1024) load
I (695) esp_image: segment 6: paddr=0x00036a10 vaddr=0x40080400 size=0x09600 ( 38400) load
I (737) esp_image: segment 7: paddr=0x00040018 vaddr=0x400d0018 size=0x62e4c (405068) map
I (847) esp_image: segment 8: paddr=0x000a2e6c vaddr=0x40089a00 size=0x06cec ( 27884) load
I (888) esp_image: segment 9: paddr=0x000a9b60 vaddr=0x400c0000 size=0x00000 ( 0) load
I (929) esp_image: segment 10: paddr=0x000a9b68 vaddr=0x50000000 size=0x00004 ( 4) load
I (971) esp_image: segment 11: paddr=0x000a9b74 vaddr=0x50000004 size=0x00000 ( 0) load
I (1012) esp_image: segment 12: paddr=0x000a9b7c vaddr=0x50000004 size=0x00000 ( 0) load
For more details on the type of memory segments and their address ranges, see the ESP32 Technical Reference Manual, Section 1.3.2 *Embedded Memory*.
3. The image has a single checksum byte after the last segment. This byte is written on a sixteen byte padded boundary, so the application image might need padding.
4. If the ``hash_appended`` field from :cpp:type:`esp_image_header_t` is set then a SHA256 checksum will be appended. The value of SHA256 is calculated on the range from first byte and up to this field. The length of this field is 32 bytes.
5. If the options :ref:`CONFIG_SECURE_SIGNED_APPS_NO_SECURE_BOOT` or :ref:`CONFIG_SECURE_BOOT_ENABLED` are enabled then the application image will have additional 68 bytes for an ECDSA signature, which includes:
* version word (4 bytes),
* signature data (64 bytes).
Application Description
-----------------------
The ``DROM`` segment starts with the :cpp:type:`esp_app_desc_t` structure which carries specific fields describing the application:
* ``secure_version`` - see :doc:`Anti-rollback</api-reference/system/ota>`.
* ``version`` - see :doc:`App version</api-reference/system/system>`. ``*``
* ``project_name`` is filled from ``PROJECT_NAME``. ``*``
* ``time`` and ``date`` - compile time and date.
* ``idf_ver`` - version of ESP-IDF. ``*``
* ``app_elf_sha256`` - contains sha256 for the elf application file.
``*`` - The maximum length is 32 characters, including null-termination character. For example, if the length of ``PROJECT_NAME`` exceeds 32 characters, the excess characters will be disregarded.
This structure is useful for identification of images uploaded OTA because it has a fixed offset = sizeof(:cpp:type:`esp_image_header_t`) + sizeof(:cpp:type:`esp_image_segment_header_t`). As soon as a device receives the first fragment containing this structure, it has all the information to determine whether the update should be continued or not.
Adding a Custom Structure to an Application
-------------------------------------------
Customer also has the opportunity to have similar structure with a fixed offset relative to the beginning of the image.
The following pattern can be used to add a custom structure to your image:
::
const __attribute__((section(".rodata_custom_desc"))) esp_custom_app_desc_t custom_app_desc = { ... }
Offset for custom structure is sizeof(:cpp:type:`esp_image_header_t`) + sizeof(:cpp:type:`esp_image_segment_header_t`) + sizeof(:cpp:type:`esp_app_desc_t`).
To guarantee that the custom structure is located in the image even if it is not used, you need to add:
* For Make: add ``COMPONENT_ADD_LDFLAGS += -u custom_app_desc`` into ``component.mk``
* For Cmake: add ``target_link_libraries(${COMPONENT_TARGET} "-u custom_app_desc")`` into ``CMakeLists.txt``
API Reference
-------------
.. include:: /_build/inc/esp_app_format.inc

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@ -23,6 +23,7 @@ System API
ESP HTTPS OTA <esp_https_ota>
ESP pthread <esp_pthread>
Error Codes and Helper Functions <esp_err>
App image format <app_image_format>
Miscellaneous System APIs <system>

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@ -188,8 +188,7 @@ Restrictions:
``security_version``:
- In application image it is stored in ``esp_app_desc`` structure. The number is set
:ref:`CONFIG_BOOTLOADER_APP_SECURE_VERSION`.
- In application image it is stored in ``esp_app_desc`` structure. The number is set :ref:`CONFIG_BOOTLOADER_APP_SECURE_VERSION`.
- In ESP32 it is stored in efuse ``EFUSE_BLK3_RDATA4_REG``. (when a eFuse bit is programmed to 1, it can never be reverted to 0). The number of bits set in this register is the ``security_version`` from app.
.. _secure-ota-updates:

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.. include:: ../../../en/api-reference/system/app_image_format.rst