Help implementing PCU SPI in Atom E3800

[AtomHelp]

Hello all,

Has anyone had any success implementing the SPI controller in the PCU in an Atom E3800 series processor?

I am trying to use the PCU SPI to configure a flash device, but I am having no luck in accessing the controller. Any reads to the SPI base address B/D/F located at 0/31/0 + 0x54 offset results in a read value of 0xFED01002.

Does anyone have any information on this? I did some research on this resulting value and upon looking at some Chipsec dumps, it seems to mean something, but I cannot figure out what exactly.

In any case, I just can't access my flash device using the SPI controller. When I attempt to read the hardware sequencing status register (HSFSTS) at offset 0x4, it returns a 0x2, indicating the FCERR bit is set. The datasheet says this is set by hardware if there's a "protection policy" configured, but it never clarifies what these "protection policies" are.

I am using an RTOS (not Linux or Windows), so I can't run any utilities.

There's very little information about this part online so I'm hoping to get answers here. Thank you for any tips or suggestions.

[Diego_INTEL]

Hello @AtomHelp,

Thank you for contacting Intel Embedded Community.

We are not supporting Bay Trail family anymore.

https://www.intel.com/content/www/us/en/support/articles/000022396/processors.html

I'm not sure if what you are trying to do can be done according to this.

https://www.mail-archive.com/coreboot@coreboot.org/msg49652.html

Also, I'm sharing the link for Bay Trail documents. You may check them to see what is available.

https://www.intel.com/content/www/us/en/products/platforms/details/bay-trail/docs.html

Best regards,

@Diego_INTEL

[AtomHelp]

Hello Diego,

Thanks for the links.

According to the Coreboot post, it seems the PCU SPI controller cannot be seen in the OS. I will continue to do research on this topic and post here if I find anything.

[Diego_INTEL]

Hello @AtomHelp,

Yes, that's why I'm not sure if it can be done but if you find anything else, it may be very interesting to know.

Best regards,

@Diego_INTEL