MicroPython board definition NUCLEO_L476RG_DFU_SOCK
Clone the board definitions to your MicroPython ports/stm32/boards folder.
cd micropython/ports/stm32/boards
git clone https://github.com/zmech/NUCLEO_L476RG_DFU_SOCK
Open NUCLEO_L476RG_DFU_SOCK folder, open mpconfigboard.h and uncomment spi flash size line wich you are using. For exsample 64 Mbit AT25SF641.
// SPI Flash(uncomment right size of flash chip)
//#define MICROPY_HW_SPIFLASH_SIZE_BITS (8 * 1024 * 1024)
//#define MICROPY_HW_SPIFLASH_SIZE_BITS (16 * 1024 * 1024)
//#define MICROPY_HW_SPIFLASH_SIZE_BITS (32 * 1024 * 1024)
#define MICROPY_HW_SPIFLASH_SIZE_BITS (64 * 1024 * 1024)
//#define MICROPY_HW_SPIFLASH_SIZE_BITS (128 * 1024 * 1024)
Save and build firmware
cd ..
make BOARD=NUCLEO_L476RG_DFU_SOCK
To put the board in DFU mode,connect the BOOT0 (CN7 pin7) to the VDD (CN7 pin5) with jumper and connect USB.
Now you can flash the board using DFU with the command:
make BOARD=NUCLEO_L476RG_DFU_SOCK deploy
Once the upload is complete, connect BOOT0 to the GND (CN7 pin8) and press reset button.