This demo is targeted towards the Olimex STM32E407 board, with 1 MB internal Flash EEPROM and 196 kB internal RAM.

To program the bootloader into the internal flash on the STM32F407 microcontroller, the Segger J-Link JTAG interface was used. However, this is not required if you have another means of programming the internal flash.

A MOD-USB-RS232 was connected to the EXT connector of the board to establish a serial communication connection between the board and the PC.

To compile the demo programs you can use the IAR Embedded Workbench for ARM development environment.

Before the bootloader can be used, it needs to be built and programmed into the STM32F407's internal flash memory. The steps in this section only need to be done once.

When using IAR EWARM, simply open the workspace from within the Embedded Workbench. The workspace file (stm32f407.eww) is located at: \Target\Demo\ARMCM4_STM32_Olimex_STM32E407_IAR\Boot\ide\. Once opened, select Project→Rebuild All from the menu to compile all the bootloader sources and link the together into the final executable.

The bootloader program is now ready to be programmed into the internal flash memory of the STM32F407. Using your favorite programmer, flash the bootloader using one of the following files, depending on what file type your programmer supports:

• \Target\Demo\ARMCM4_STM32_Olimex_STM32E407_IAR\Boot\bin\openbtl_olimex_stm32e407.elf
• \Target\Demo\ARMCM4_STM32_Olimex_STM32E407_IAR\Boot\bin\openbtl_olimex_stm32e407.srec

The Microboot utility needs to be configured to connect to the correct COM-port and to communication at the correct baudrate:

• Start Microboot by double-clicking “\Host\MicroBoot.exe”.
• Click the “Settings”-button and select “OpenBLT using UART” from the dropdown box.
• Click the “Options”-button to configure the communication parameters.
  • Select the PC's COM-port that the board is connected to.
  • Set the baudrate to 57600 bits/sec.

Once you saved the settings by clicking the “OK”-button twice, you can close Microboot by clicking the “Cancel”-button on the main screen. Microboot is now ready for action!

When using IAR EWARM, simply open the workspace from within the Embedded Workbench. The workspace file (stm32f407.eww) is located at: \Target\Demo\ARMCM4_STM32_Olimex_STM32E407_IAR\Prog\ide\. Once opened, select Project→Rebuild All from the menu to compile all the demo program sources and link the together into the final executable.

The output file is

• \Target\Demo\ARMCM4_STM32_Olimex_STM32E407_IAR\Prog\bin\demoprog_olimex_stm32e407.srec

To download this demoprog_olimex_stm32e407.srec file to the remaining flash memory using the bootloader, start the Microboot program and click the “Browse”-button. Browse to the “\Target\Demo\ARMCM4_STM32_Olimex_STM32E407_IAR\Prog\bin\” directory and select the demoprog_olimex_stm32e407.srec file to start the download.

Once the download completed, the newly programmed software will be started by the bootloader. You can verify this by checking that the status LED blinks. Congratulations! That's all there is to using the bootloader.

In addition to the previously described update procedure with Microboot, the bootloader demo is configured for making firmware updates from an SD-card. The procedure is:

1. Insert the SD-card into your PC and store the firmware file demoprog_olimex_stm32e407.srec on it.
2. Insert the SD-card into the card holder on the microcontroller board.
3. Reset the microcontroller to start the firmware update. Once done, the newly programmed firmware is automatically started.

The bootloader demo is configured to output log messages to a serial terminal. This enables you to view the progress of the firmware update with a terminal program such as Putty. The communication settings are the same as those described above in section Configuring Microboot. Additionally, the log messages are written to a file called bootlog.txt on the SD-card, which can optionally be checked for verification purposes.