creating bootloader for sensor tile

[Dilbert K]

Posted on September 29, 2017 at 21:33

I am using the ST SensorTile for development.  Now trying to understand the OTA and Bootloader.

Currently only able to find the binary for bootloader.

Does ST provide source code / project to build our own bootloader ?

As I would like to add the DFU into bootloader support.

[Nesrine M_O]

Posted on October 02, 2017 at 09:57

Hi

K.Dilbert

,

The embedded bootloader code is located in the system memory. It is programmed by ST during production. For full information, refer to the application note (

http://www.st.com/content/ccc/resource/technical/document/application_note/b9/9b/16/3a/12/1e/40/0c/CD001675pdf/files/CD001675pdf/jcr:content/translations/en.CD001675pdf

) STM32 microcontroller system memory boot mode.

-Nesrine-

[Dilbert K]

Posted on October 09, 2017 at 21:54

Hi Nesrine,

As I want to try out the DFU on ST SensorTile, I check the schematic again, the BOOT0 is connected to GND.

Is that meant, I would not able to test DFU for this platform ??

Regards

[Dilbert K]

Posted on October 09, 2017 at 22:48

I also got a B-L475E-IOT01A discovery board, but search the User Guide, do not find procedure how to enter DF mode.

[Tesla DeLorean]

Posted on October 10, 2017 at 02:47

I'd suppose the easiest way would be to map the ROM at zero and jump into it.

[Dilbert K]

Posted on October 18, 2017 at 04:15

Not that simple as the bootloader will see a valid Application, then it will continue.

I got info from others to use a series of '

FLASH_OB_

' functions to clear the OptionByte in order to force into DFU mode using SW.

One other way yet to try is, STLink to erase the current application in Flash. 

[Dilbert K]

Posted on October 18, 2017 at 04:20

Hi Nesrine,

After reading the AN2606, I got more questions now.  I am using the STML476 and doc indicate there are 2 version V9 and V10 supported.

When I got the 'STM32CubeFunctionPack_MOTENV1_V3.0.0', it came with V9.

Where can I get the official release package for each STM32 bootloader ?

Since the V9 is using a dual flash image page method, but I would like a different method to implement the boot sequence & OTA.

Will ST provide the source code for Bootloader ?

Best Regards

[Girish Karnavat]

Posted on November 14, 2017 at 16:24

STM32 typically have a bootloader in system memory that can be used through various communication interfaces. In your case you are referring to the DFU USB bootloader.

See link below to the overview of which types of bootloaders are located on the STM32.

http://www.st.com/content/ccc/resource/technical/document/application_note/b9/9b/16/3a/12/1e/40/0c/CD00167594.pdf/files/CD00167594.pdf/jcr:content/translations/en.CD00167594.pdf

Here is a more in depth explanation about the USB bootloader.

http://www.st.com/content/ccc/resource/technical/document/application_note/6a/17/92/02/58/98/45/0c/CD00264379.pdf/files/CD00264379.pdf/jcr:content/translations/en.CD00264379.pdf

The sensor tile microcontroller is the STM32L476JGY. We have examples in our STM32 Cube L4 firmware library that is based on a similar microcontroller but a different package and memory size, 32L476GDISCOVERY. See link below.

http://www.st.com/content/st_com/en/products/evaluation-tools/product-evaluation-tools/mcu-eval-tools/stm32-mcu-eval-tools/stm32-mcu-discovery-kits/32l476gdiscovery.html

The example firmware code for this discovery kit for DFU USB bootloader can be found in the STM32CubeL4, 

http://www.st.com/content/st_com/en/products/embedded-software/mcus-embedded-software/stm32-embedded-software/stm32cube-embedded-software/stm32cubel4.html

If you unzip the folder structure you can find the example firmware here “\STM32Cube_FW_L4_V1.9.0\Projects\STM32L476G-Discovery\Applications\USB_Device\DFU_Standalone�