Arty Z7-20 Booting from Flash with Encryption Enabled

[ccattell]

Hello Everyone,

 

I am trying to get my Arty Z7-20 (XC7Z020) to boot from flash with encryption enabled. If I do not enable encryption, I am able to get this to work. 

 

I am using the tool "Create Boot Image" in the Xilinx SDK. I open the encryption tab and check the box labeled "Use Encryption" and provide the "Part name." The Part name I use is "XC7Z020." I have also tried "XC7Z020CLG400", which I found when using that board in a Vivado project. The Boot Image is created just fine, and I am able to program the flash. However, when I power on the FPGA, the done light does not come on and it seems to get stuck booting.

 

I do have the jumper set to QSPI. Any idea why I am having this issue? 

 

Thanks,

Christian

[jpeyron]

Hi @ccattell,

You are referring to using the efuse? I do not have experience using the efuse. Here is a fsbl that has the efuse status register information. Here and here are more information about efuse.

thank you,

Jon

[ccattell]

7 minutes ago, jpeyron said:

Hi @ccattell,

You are referring to using the efuse register? I do not have experience using the efuse. Here is a fsbl that has the efuse status register information. Here and here are more information about efuse.

thank you,

Jon

Hello @jpeyron,

I am trying to use bbram. I should've specified that in the original post, sorry for the confusion. Please let me know if there is anything else that is unclear about my issue.

Thanks,

Christian  

[jpeyron]

Hi @ccattell,

Here is pdf the discusses Battery Backed Up RAM. Here is a xilinx forum thread that discusses the bbram as well.

thank you,

Jon

[ccattell]

Thanks @jpeyron, 

Do you know if the Arty Z7 comes with a battery for the bbram? I just assumed it would, as the A7 did.

[jpeyron]

Hi @ccattell,

Looking at the Zynq-7000 SoC Data Sheet: Overview on page 12 under Configuration and miscellaneous it discusses eFUSE and battery-backed RAM signals from the PL to the PS. This is  also discussed in the 7 Series FPGAs Data Sheet: Overview on page 14 where it states that the key can reside in battery-backed RAM or in nonvolatile eFUSE bits. It looks like the bbram feature is in zynq like it is in the Artix-7 FPGA's. I unfortunately have no experience with these functions. I would suggest to reach out to xilinx support about this forum thread. I did also find newer information about BBram and efuse in the Internal Programming of BBRAM and eFUSEs as well.

cheers,

Jon

 

 

[ccattell]

Hi @jpeyron,

Thanks for your help. I'll keep digging and try my luck on the Xilinx forums too. 

 

Christian

[ccattell]

Update: According to a Xilinx employee, the Z7 does not come with a battery for BBRAM. That would explain what was causing my issue. 

[jpeyron]

Hi @ccattell,

I am glad that you were able figure out what was causing the issue. Thank you for sharing what you found.

cheers,

Jon