STM32H562 program the OBK file with trustzone disabled

[Nluke.1]

We need to develop an offline programmer to program the STM32H562VIT. The product state need to be changed to Closed with an OBK file programmed. The OBK data only in HDPL1.

We can't simply use the RSS to program the OBK like STM32Cubeprogrammer. We could only write and read the flash registers by SWD.

When in OPEN state, we could program the OBK files successfully, then we change the state to provisioning and closed. But if we first change the state to Provisioning, then try to program the OBK data , the programming of OBK is always failed.

So our questions is how to program the OBK file  data when in Provisioning state for a third programmer?

[Jocelyn RICARD]

Hello @Nluke.1 ,

In STM32H562, the OBK are not encrypted.

This means you can provision in open state as you already do.

The main reason for provisioning OBK in provisioning state is to be able to encrypt OBK using DHUK.

DHUK is not available in open state.

In non crypto devices, the tools use the same mechanism but this is only for consistency.

Best regards

Jocelyn

[Nluke.1]

Hi Jocelyn,

thanks for your prompt reply. So I could handle this case without nervous.

But actually our offline programmer is also needed to support  programming OBK in STM32H573 in the next project.

The OBK for STM32H573 is also password as the trustzone not enabled.

1.So could we operate the STM32H573 the same way as STM32H562?

2. Could we operate all the STM32H562 and STM32H573 this way  if the encryption flag in OBK file header is not enabled?

In order to support different OBK in the future, It's better if you could provide some detailed document to program the OBK no matter the OBK needs encryption or not. 

Best regards

Luke