CycloneBOOT is a secure bootloader and firmware update library for STM32 and Microchip SAM microcontrollers (Arm Cortex-M). It receives, verifies, decrypts and installs firmware updates, checks the application before every start, and returns to the previous firmware when an update fails.

To try it on a board and integrate it into a project, see Getting Started.

Features

Update images checked by an integrity check (CRC32, MD5, SHA-1, SHA-2), HMAC authentication, or an RSA (2048 to 4096 bits) or ECDSA (P-256, P-384, P-521) signature
AES-CBC encrypted update images, and encryption of images held in external memory
Verified boot: the bootloader checks the signature or the hash of the application before every start
Anti-rollback: an image older than the running firmware is refused
Fallback to the previous firmware, and resumed installation after a power loss
Optional first-stage bootloader, so that the second-stage bootloader can be updated in the field
Internal flash and external NOR flash (Quad-SPI, Octal-SPI), including execute-in-place (XiP)
No dynamic memory allocation
ImageBuilder, a command-line tool for Linux and Windows that builds signed and encrypted update images and generates signing keys

Update Modes

Mode	Components	Use it when	Demo folder
Dual-bank	Update library in the application; the MCU swaps flash banks	The MCU has dual-bank flash and no bootloader is wanted	`iap_dual_bank`
Hybrid	Update library in the application, bootloader at the flash base	Verified boot, fallback or external memory is needed, on any MCU	`hybrid_app_bl`
Standalone	Bootloader that receives the update itself (UART, TFTP, HTTP)	The application carries no update code, or the device must recover without a working application	`standalone_bl`

Demo folders are demo/<vendor>/<board>/<mode>/. An overview of the boards and protocols is at https://www.oryx-embedded.com/resources/open-source-secure-bootloader-demos.html

Supported Devices

MCU family	Flash and MCU drivers
STM32	C0, C5, F4, F7, G0, G4, H5, H7, H7RS, L4, L5, N6, U0, U3, U5, WB
Microchip SAM	D5x/E5x, E7x
External NOR flash	AT25SF128A, M29W128GL, MT25TL01G, MX25L512, MX25LM51245G, MX25UM51245G, MX66UW1G45G, N25Q512A

A new MCU family needs a flash driver and an MCU driver, in src/cyclone_boot/drivers/.

Download and License

CycloneBOOT Open, with the full source code, the demos and ImageBuilder, is available under the GNU General Public License v2.0 or later: https://www.oryx-embedded.com/download/CycloneBOOT.html

Commercial editions (Lite, Pro, Ultimate) are available for closed-source products: https://www.oryx-embedded.com/licensing/commercial/CycloneBOOT.html