on - edited on by
Laurids_PETERSE
Summary
This example uses the STM32U5 Nucleo board with STM32U5A5ZJT6Q and STM32CubeProgrammer V2.13.
Note:
To regress from RDP2 to RDP0, you must be sure that your password has been defined in OEM2KEY. Otherwise, case regression is not possible.
1. How to define an OEM password
To define an OEM2 password, you must do the following:
1.Check if your sample is on RDP level 0 (no protection).
2. In the "secure programming" menu, define your password.
3. Click on "set password" and after on "apply lock RDP2."
At this point, you are sure that the OEM2Key is correctly defined.
2. How to take the RDP from level 0 to level 2
1. In the "read out protection" menu, select the value “CC" then click on apply.
After clicking on "ok" you will lose your connection with STLINK. This is normal behavior.
3. How to regress from RDP level 2 to level 0
Go back to the "secure programming" menu:
1. Click on "Unlock RDP2" and after on "Apply unlock RDP2."
You receive an error message but in your log window, you can read "Unlock RDP2 password successfully done."
2. After clicking on "ok" reconnect your card with STLINK, then check the device authentication ID by clicking on "Read."
3. Disable the RDP regression with a password.
4. Go back to the "Read Out Protection" menu and check the value of the RDP.
5. Change the RDP value to “AA” then click on apply.
You have correctly downgraded the RDP from level 2 to level 0.
Hello @Manuel Ferrero @RCana.2
This is a tool bug where step 1 has to be done twice.
Workaround :
Can you retest on your two boards by doing step 1 <<Go back to the "secure programming" menu and Click on "Unlock RDP2" and after on "Apply unlock RDP2">> 2 times before moving on to step 2?
if you have correctly defined your password, no worries, go back directly from this step, you can regress to level 0.
Internal ticket has been created to solve this bug.
Internal ticket number: 157559 (This is an internal tracking number and is not accessible or usable by customers).
Regards
Diane
@Diane POMABIA , @Jocelyn RICARD hello, I'm working on a STM32U595 and I encountered the same issue (not being able to do the regression from RDP2 to RDP1 even with my OEMKEY1 and 2 set etc.
First of all I configured OEMKEY1 and 2 :
Then I followed the full process using Reference Manual + a nice tutorial by ST
However, it doesn't work, I have two weird behavior :
If I use STM32CubeProgrammer I can read the Auth device ID :
But I can't unlock RDP2 (By the way I tried twice as you answered above):
I tried in command line and what a surprise to see " Unlock RDP2 password failed!"
At some point, I was like "oh it's me, I typed the wrong password", so I tried on an other STM32U595, we were two doing it, so double check. Same issue happened.
Could you help me regarding this issue. By the way I was using STM32CubeProgrammer 2.14 (last version), I was Under Reset for unlock sequence, and hotplug mode to get auth device. I also tried to save my chip by putting 3.3V on BOOT0 pin, but looks like I can't connect to debugger or do anything more.
Kind regards
