Embedded board bootloaders and their quirks

embedded_bootloader_quirks.md

Micropython

• Source code
• Allows firmware update via USB (and possibly other methods?)
• The is 128 kB minimum, some boards reserve 256 kB (eg OpenMV)
• The jump address varies depending on the board
• Example: OpenMV H7 board bootloader is 128 kB in size, reserves 256 kB in flash, and has an application jump address of 0x8040000

PX4

• Source code
• Allows firmware update via USB, CAN (and other?)
• The size varies depending on the board. Common sizes are 16 kB and 32 kB.
• The jump address varies depending on the board (and size). Search APP_LOAD_ADDRESS in hw_config.h
• Example: PX4FLOW board bootloader is 16 kB in size and has an application jump address of 0x08004000

Cleanflight

• Source code
• Allows firmware update via USB (and others?)
• The size varies widely depending on the board, from 16 kB - 128 kB currently.
• The jump address varies depending on the board (and size)
• Example: One stm32h743 bootloader is 128 kB in size, reserves another 128 kB for configuration, and has an application jump address of 0x08040000

STM32-duino Arduino bootloader for STM32

• Source code
• Allows same firmware update methods as older Arduino bootloader
• Size is 8 kB, and only a limited set of STM32 boards are supported (eg stm32f103)
• Application jump address is 0X8002000

Adafruit ntf52 Arduino

• Source code

Adafruit nrf52

• Not Arduino-specific
• Source code

Caterina

• Yet another Arduino bootloader
• Source code

MCUboot

• Source code
• Compiled into eg Zephyr and MyNewt binaries