1.8 KiB
Mboot - MicroPython boot loader
Mboot is a custom bootloader for STM32 MCUs, and currently supports the STM32F4xx and STM32F7xx families. It can provide a standard USB DFU interface on either the FS or HS peripherals, as well as a sophisticated, custom I2C interface. It fits in 16k of flash space.
How to use
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Configure your board to use a boot loader by editing the mpconfigboard.mk and mpconfigboard.h files. For example, for an F767 be sure to have these lines in mpconfigboard.mk:
LD_FILES = boards/stm32f767.ld boards/common_bl.ld TEXT0_ADDR = 0x08008000
And this in mpconfigboard.h (recommended to put at the end of the file):
// Bootloader configuration #define MBOOT_I2C_PERIPH_ID 1 #define MBOOT_I2C_SCL (pin_B8) #define MBOOT_I2C_SDA (pin_B9) #define MBOOT_I2C_ALTFUNC (4)
To configure a pin to force entry into the boot loader the following options can be used (with example configuration):
#define MBOOT_BOOTPIN_PIN (pin_A0) #define MBOOT_BOOTPIN_PULL (MP_HAL_PIN_PULL_UP) #define MBOOT_BOOTPIN_ACTIVE (0)
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Build the board's main application firmware as usual.
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Build mboot via:
$ cd mboot $ make BOARD=
That should produce a DFU file for mboot. It can be deployed using USB DFU programming via (it will be placed at location 0x08000000):
$ make BOARD= deploy
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Reset the board while holding USR until all 3 LEDs are lit (the 4th option in the cycle) and then release USR. LED0 will then blink once per second to indicate that it's in mboot
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Use either USB DFU or I2C to download firmware. The script mboot.py shows how to communicate with the I2C boot loader interface. It should be run on a pyboard connected via I2C to the target board.