Reference example for FreeRTOS with MCUBoot support.
MCUBoot is a configurable secure bootloader maintained by several industry leaders. It can operate as the first or second stage bootloader, with support for cryptographic verification of software images via one of the following:
- ECDSA-P256
- RSA-2048
- RSA-3072
By default, it supports image reversion whereby uploaded image upgrades are tentatively booted once. Upon and image's initial boot, if the upgrade image marks itself as confirmed it is retained as the primary image. If the upgrade image is not confirmed, the subsequent boot will rollback to the prior confirmed image. If no valid image is available in any slot, the device bricks itself as a safety precaution. The developers of MCUBoot provide more detailed documentation here (https://github.com/mcu-tools/mcuboot/tree/main/docs).
MCUBoot also provides subset support for mcumgr when a device enters serial boot recovery mode. If enabled, serial mode can be triggered during bootup via user input, such as a button hold. MCUMGR interface enables users to retrieve image diagnostics from the board, query resets, upload/modify images, and more.
The demo consists of MCUBoot booting an application which first disables a bootloader watchdog timer, prints its version number, then confirms itself so it won’t be reverted if it's an update. The app proceeds to periodically print “hello world”.
The demo also details the application signing and upgrade process, and provides a porting guide for implementing on other SoCs. Finally, use of mcumgr is demonstrated for retrieving image diagnostics, modifying/uploading images, and triggering other board functions from your host PC.
| Supported SoCs |
|---|
| Espressif esp32 |
The mcuboot.patch provides:
- Bug fixes
- Implants hooks for replacing function calls that were specific to other RTOS
- Provides
boot/freertoscontent - Bug fixes and enhancements to MCUBoot's Espressif port
The esp-idf.patch provides:
- IDF capability to build and format applications for Espressif's MCUBoot application loader
This library is licensed under the MIT-0 License. See the LICENSE file.