====== ARM-CM0 STM32 Nucleo-G071RB GCC ======

===== Supported firmware update interfaces =====

^ RS232         ^ CAN            ^ USB         ^ TCP/IP      ^ SD-card      ^ Modbus RTU   ^
| Yes           | No             | No          | No          | No           | No           |

===== Development Environment =====

{{:manual:demos:stm32_nucleo_g071rb.png? |}}

This demo is targeted towards the [[https://www.st.com/en/evaluation-tools/nucleo-g071rb.html|Nucleo-G071RB]] board, with 128 kB internal Flash EEPROM and 36 kB internal RAM.

To build the demo programs you can use the [[https://developer.arm.com/open-source/gnu-toolchain/gnu-rm|GNU ARM Embedded]] toolchain.

To program the bootloader into the internal flash, the on-board ST-Link debugger interface was used. Firmware updates via the serial communication port are preconfigured to use the virtual COM-port offered by the ST-Link. This means that no additional hardware is needed, besides a standard micro-USB cable.


===== Toolchain configuration =====

The demo programs are configured for building with a Makefile. Before attempting to perform a build, update the location of the toolchain binaries (i.e. //arm-none-eabi-gcc//) in the Makefile. It is set in variable **TOOL_PATH**. If the toolchain binaries are available on the path, then the **TOOL_PATH** variable can be left empty.

{{:manual:demos:makefile_toolpath.png?nolink&|}}

It is assumed that tools such as GNU //make// and //rm// are installed and available on the path. For (Ubuntu) Linux users this can be achieved by running command: //sudo apt-get install build-essential//. Windows users can install the [[https://gnu-mcu-eclipse.github.io/windows-build-tools/|GNU MCU Eclipse Windows Build Tools]].

===== Building and programming the Bootloader =====

Before the bootloader can be used, it needs to be built and programmed into the STM32G071's internal flash memory. The steps in this section only need to be done once.

To build the bootloader, open a command prompt in directory **\Target\Demo\ARMCM0_STM32G0_Nucleo_G071RB_GCC\Boot\** and run the command:

<code>
make clean all
</code>
 
The expected output is:

<code>
+++ Cleaning build environment
+++ Clean complete
+++ Assembling [startup_stm32g071xx.s]
+++ Compiling [hooks.c]
+++ Compiling [main.c]
...
+++ Linking [openblt_stm32g071.elf]
...
+++ Build complete [openblt_stm32g071.srec]
</code>

The bootloader program is now ready to be programmed into the internal flash memory of the STM32G071. Using your favorite programmer (i.e. OpenOCD or STM32 ST-Link utility), flash the bootloader using one of the following files, depending on what file type your programmer supports:

  * \Target\Demo\ARMCM0_STM32G0_Nucleo_G071RB_GCC\**Boot**\bin\**openblt_stm32g071.elf**
  * \Target\Demo\ARMCM0_STM32G0_Nucleo_G071RB_GCC\**Boot**\bin\**openblt_stm32g071.srec**

===== Building the Demo Program =====

To build the user program, open a command prompt in directory **\Target\Demo\ARMCM0_STM32G0_Nucleo_G071RB_GCC\Prog\** and run the command:

<code>
make clean all
</code>
 
The expected output is:

<code>
+++ Cleaning build environment
+++ Clean complete
+++ Assembling [startup_stm32g071xx.s]
+++ Compiling [main.c]
+++ Compiling [boot.c]
...
+++ Linking [demoprog_stm32g071.elf]
...
+++ Build complete [demoprog_stm32g071.srec]
</code>

The output file is

  * \Target\Demo\ARMCM0_STM32G0_Nucleo_G071RB_GCC\**Prog**\bin\**demoprog_stm32g071.srec**

===== Firmware update procedure =====

To download the demo program \Target\Demo\ARMCM0_STM32G0_Nucleo_G071RB_GCC\**Prog**\bin\**demoprog_stm32g071.srec** using the bootloader, follow the instructions in the following links, depending on the communication interface you intend to use:

  * [[manual:rs232_demo|Firmware updates using the RS232 communication interface]]