Re: [OpenOCD-devel] STM32VLDiscovery, OpenOCD and Read Protection Bit

[Spencer O. <sp...@sp...>]

On 06/09/12 18:57, Simon Küppers wrote:
> Dear Folks,
>
> Im currently trying to use OpenOCD together with a STM32VLDiscovery, which basically is a STLINK/V1 tied to an STM32F100 via SWD.
>
> Actually, everything works OK, but one thing I can not figure out is how to disable the Read Protection.
>
> I wrote a small test application, which would flash an LED on the board. Then I tried to load the firmware onto the STM32F100 using STM's STVP-Tool, with the STLINK/V1 being installed as a mass-storage device.
>
> This works as expected, after disabling the Read Protection.
>
> Now I am trying to move to OpenOCD. I installed the WinUSB driver using the "Zadig" Tool, with no problems. A quick test with OpenOCD shows that everything is fine with the STLINK/V1:
>

The issue is caused because the stlink does not support 16bit writes 
that are needed for option byte writing.

we do have a patch pending - http://openocd.zylin.com/480
however a better approach is to add a 16bit read/write routine for the 
stlink.

unlock the device using other means and do not perform a flash protect 
or unlock and you be fine.

Think what i may do is add a warning before the 0.6 release to state 
that option byte writing is not supported for stlink.

Cheers
Spen