Locking debug access on STM32F devices

simon_parkas · ‎2009-10-29

Posted on October 29, 2009 at 15:39

simon_parkas · ‎2011-05-17

Posted on May 17, 2011 at 13:28

I can't find any detailed information on locking debug access to the device.

Yes there is information on how to protect the flash memory (PM0042) but hardly any information on how to disable debug access.

The only hint I found is in the Reference Manual (RM0008) on page 958:

Quote:

ID codes and locking mechanism

There are several ID codes inside the STM32F10xxx MCU. ST strongly recommends tools designers to lock their debuggers using the MCU DEVICE ID code located in the external PPB memory map at address 0xE0042000.

Is there any documentations available that specifically deals with disabling debug access and its technical limitation in more detail?

Cheers,

Simon

jvaque · ‎2011-05-17

Posted on May 17, 2011 at 13:28

From user manual UM0427, page 182,

GPIO_PinRemapConfig(GPIO_Remap_SWJ_Disable, ENABLE);

disables SWJ, which is for debug.

regards,

simon_parkas · ‎2011-05-17

Posted on May 17, 2011 at 13:28

Thanks jvaque.

However, UM0427 seems to be quite elusive.. I did use ST's search engine and tried Google but to no avail.

Even here:

http://www.st.com/mcu/familiesdocs-110.html

, no mention of UM0427.

Could you please provide a link or be more specific where the document can be obtained from.

Thanks

simon_parkas · ‎2011-05-17

Posted on May 17, 2011 at 13:28

Thanks Clive.

-

Still pretty sparse information from ST scattered across many different documents and overall nonsatisfying unless you develop an open source product.

I wish STMicroelectronics would follow other vendor's footsteps and provide all (security and debug) relevant documentation in one place. At the moment in my opinion it seems that this is a weak spot in the STM32 documentation as I assume that the technical mechanism does exist in silicate - just not on paper and therefore not fully or easily accessible to developers.

Regards,

Simon

clive2 · ‎2011-05-17

Posted on May 17, 2011 at 13:28

It got deprecated when the new FW library was released, page 17 is the relevant GPIO description.

http://space.ednchina.com/Upload/Blog/2008/3/11/76d20df5-d7f0-4993-9d9c-851c132fbd6c.pdf

-Clive