# ABOUT This repository contains bare-metal firmware for a Cortex-M4 STM32 microcontroller (STM32F446RE in my case), using open source tools and libraries such as GCC for ARM and STM HAL. The project purpuse is to build a bootloader for performing firmware updates over UART. # DEBUGGER In this project i've used the ST-Link DEBUGGER and Programmer attached to the board, in my case i've used NUCLEO STM32F446RE # The supported bootloader commands | Host Command | Command Code | Bootloader Reply | Notes | | --------------------- | ------------ | ------------------------------------------- | ---------------------------------------------------------------------------- | | BL_GET_VER | 0x51 | Bootloader version number (1 byte) | This command is used to read the bootloader version from the MCU. | | BL_GET_HELP | 0x52 | All supported command code (10 bytes) | This command is used to get what commands are supported. | | BL_GET_CID | 0x53 | Chip identification (2 bytes) | This command is used to get MCU chip identification number. | | BL_GET_RDP_STATUS | 0x54 | Flash read protection level (1 byte) | This command is used to get Flash read protection level. | | BL_GO_TO_ADDR | 0x55 | Success or Error code (1 byte) | This command is used to jump the bootloader to the specified address. | | BL_FLASH_ERASE | 0x56 | Success or Error Code (1 byte) | This command is used to erase sectors of the user flash. | | BL_MEM_WRITE | 0x57 | Success or Error Code (1 byte) | This command is used to write data to the specified MCU memory. | | BL_EN_RW_PROTECT | 0x58 | Success or Error Code (1 byte) | This command is used to enable read/write protection on different sections. | | BL_DIS_RW_PROTECT | 0x5C | Success or Error Code (1 byte) | This command is used to disable read/write protection on different sections. | | BL_READ_SECTOR_STATUS | 0x5A | All sectors status (2 bytes) | This command is used to read all the sector protection status. | # STMBoatloader