Reading STM32 unique device ID using OpenOCD

When working with the STM32 family of microcontrollers, it can be useful to evaluate the factory-programmed 96-bit UUID using JTAG. On all major operating systems, OpenOCD provides a simple yet highly compatible and free solution in order to do this.

In this example, we’ll use a JLink adapter together with the Olimex E407 evalation board. Both the adapter and the board are interchangable, provided you have working OpenOCD configurations available.

According to the STM32F4 reference manual, the UUID is stored in memory at address 0x1FFF 7A10 (see section 39.1). Starting from this address, we have to read three times 32 bits (i.e. 3 words) of memory to get the full UUID.

In order to do this, we can use the mdw command as documented under OpenOCD General commands

openocd -f interface/jlink.cfg -f olimex-e407.cfg -c "init" -c "$target_name mdw 0x1FFF7A10 3" -c "exit"

This script tells OpenOCD to first initialize the target device, the read 3 words starting at 0x1FFF7A10 and then exit immediately.

Example output:

Open On-Chip Debugger 0.7.0 (2013-06-15-20:16)
Licensed under GNU GPL v2
For bug reports, read
        http://openocd.sourceforge.net/doc/doxygen/bugs.html
Info : only one transport option; autoselect 'jtag'
adapter speed: 1000 kHz
adapter_nsrst_delay: 100
jtag_ntrst_delay: 100
cortex_m3 reset_config sysresetreq
Info : J-Link initialization started / target CPU reset initiated
Info : J-Link ARM V8 compiled Jun 19 2012 11:29:30
Info : J-Link caps 0xb9ff7bbf
Info : J-Link hw version 80000
Info : J-Link hw type J-Link
Info : J-Link max mem block 9320
Info : J-Link configuration
Info : USB-Address: 0x0
Info : Kickstart power on JTAG-pin 19: 0xffffffff
Info : Vref = 3.345 TCK = 1 TDI = 0 TDO = 0 TMS = 0 SRST = 0 TRST = 0
Info : J-Link JTAG Interface ready
Info : clock speed 1000 kHz
Info : JTAG tap: stm32f4x.cpu tap/device found: 0x4ba00477 (mfg: 0x23b, part: 0xba00, ver: 0x4)
Info : JTAG tap: stm32f4x.bs tap/device found: 0x06413041 (mfg: 0x020, part: 0x6413, ver: 0x0)
Info : stm32f4x.cpu: hardware has 6 breakpoints, 4 watchpoints
0x1fff7a10: 00370021 32314718 39313739

The last line first display the address read, followed by three hexadecimal numbers representing the three 32-bit UUID parts.

When using other boards or interfaces, just replace the scripts referenced by -f by the appropriate OpenOCD scripts.

Although I have not checked this in detail, I assume other STM32 families store the UUID at the same address.