Recovering STM32U3 from RDP2 level to RDP1 level

[deva2k]

Hi team,

I provisioned both OEM1 and OEM2 keys. I locked the device using OEM2 key and then put the device in RDP level 2 with the below commands:

STM32_Programmer_CLI.exe -c port=SWD mode=hotplug -lockRDP2 0xFEDCBA98 0x76543210

Response: "Lock RDP2 password successfully done"

Enable RDP2: STM32_Programmer_CLI.exe -c port=SWD mode=hotplug -ob RDP=0xCC

If you see here I used only <word1> and <word2> for password because I followed the below video for STM32U5:

URL: https://www.youtube.com/watch?v=B3l6iuA7U8Q&t=752s

But STM32U3 series uses 128 bits of password rather than 64 bits used by STM32U5 series.

Could anyone know/share default value that will be passed if we have missed <word3> and <word4>.

[KDJEM.1 · Accepted solution]

Hello @deva2k and welcome to the community;

Thank you for bringing this issue to our attention.

The expected behavior that a warning/error message should be displayed when you define two words.

The Bits[64:127] are written as zero so in reality OEM2KEY = 0xFEDCBA98 0x76543210 0X00000000 0X00000000.

I reported this issue internally.

 Internal ticket number is reported : 195040 (This is an internal tracking number and is not accessible or usable by customers)

Thank you.

Kaouthar

[deva2k]

Hello @KDJEM.1 

The Bits[64:127] are written as zero so in reality OEM2KEY = 0xFEDCBA98 0x76543210 0X00000000 0X00000000.

The above password worked. Thanks!

Just to clarify, when TrustZone (TZEN) is enabled, you need to set BOOT0 to high by connecting it to 3.3V.

[KDJEM.1]

Hello @deva2k ,

Glad to know that the issue is solved.

The STM32CubeProgrammer issue is reported under 195040 ticket.

I will let you know when the issue is fixed.

Thank you for your contribution in STCommunity.

Kaouthar