Arm Mbed OS support forum

Custom board target WITHOUT bootloader

Hello all,

My goal is to have a running blinky using RTOS and a custom board.
The custom board is based on the STM32F427ZITx microcontroller. I have ported all necessary files and I can build the code. However I keep getting the following (non-blocking) errors during the build:

Configuration error: Bootloader not supported on this target.
ConfigException: Bootloader not supported on this target.
[mbed] ERROR: “C:\Python27\python.exe” returned error.

In my custom_targets.json, I have set the following properties:

		"device_name": "STM32F427ZITx",
		"mbed_rom_start": "0x08000000",
		"mbed_rom_size": "0x100000",
		"mbed_ram_start": "0x200001B0",
		"mbed_ram_size": "0x‭2FE50‬",
		"bootloader_supported": false

Which I assume would mean the build tools would know I currently have no desire to use a bootloader.
I’ve also tried using mbed_app_start and mbed_app_size instead of rom.

Out of ideas, I checked the Python file where the error originated from (mbed-os\tools\

        if not getattr(, "bootloader_supported", False):
            raise ConfigException("Bootloader not supported on this target.")

So seemingly it is not finding my bootloader_supported? I’m not sure why that would be the case, because if I print out there, I can find bootloader_supported is False.

Thank you in advance for any and all help.

It seems if I don’t define the regions, it works fine. I guess I understand now!

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