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BBerg7
New Contributor I
2,773 Views

Any differences in Bay Trail Z37xx series versus E38xx series......

Hi,

Z37xx series looks like a subset of E38xx series. Accordingly, the same firmware code used for E38xx series may work on Z37xx series, just leaving out the code for the missing devices. In theory the same MRC code will work with all Baytrail series.

As an example, adoption of E3845 firmware to Z3735F firmware would be accomplished as follows.

  • Modify flash descriptor to reflect Baytrail-T architecture
  • Remove any code initializing hardware missing in the chip
  • Replace Baytrai-I microcode with Baytrail-T microcode

This should work, unless there are any hidden quirks regarding the Baytrail-T architecture. So my questions are as follows:

  1. Is there another MRC used for Baytrail-T than for Baytrail-I, or can the Baytrail-I MRC work unmodified on Baytrail-T?
  2. Do you have an alternate FSP package for Baytrail-T or what should be changed in the FSP package to support Baytrail-T?

Best regards,

B-O

0 Kudos
23 Replies
idata
Community Manager
136 Views

Hi B-O,

Welcome back to the Intel Embedded Community.

We're working on your case, as soon as we have more information we'll write back.

Best regards,

Jimmy.

CarlosAM_INTEL
Moderator
136 Views

Hello B-O,

 

We are still working to provide you an update.

 

Thanks in advance for your patience and understanding.

 

Best Regards,

Carlos A.

 

Marcelo_M_Intel
Employee
136 Views

Hello B-O,

MRC – Memory Reference Code – is the DRAM/Memory-Controller initialization flow performed by BIOS before DRAM is enabled for functional access.

For more information about the BIOS MRC compatibility please review this documents with the assistance of your BIOS developer.

Please refer to this documents for information about the MRC flow selection.

Document# 537532, Revision 1.1, https://www-ssl.intel.com/content/www/us/en/secure/embedded/nda/products/bay-trail/atom-z3600-3700-b... Intel® Atom™ Processor Z3600 and Z3700 Series SoC BIOS Writers Guide - Volume 2 of 2, section 19.4.1 MRC Flow Selection.

Document # 514148, Revision 1.43, https://www-ssl.intel.com/content/www/us/en/secure/intelligent-systems/privileged/bay-trail/atom-e38... Bay Trail-M/D SoC BIOS Writers Guide - Volume 2 of 2, section 19.4.2 MRC Flow Selection.

Please let me know if you have any other question.

Best regards,

Marcelo

BBerg7
New Contributor I
136 Views

Thank you Marcello!

I have found some differences not covered by the documents mentioned above.

E38xx series will start the CPU without having a TXE region in the flash memory. Z37xx series will not come out of reset without a valid TXE region in the flash memory. So if your firmware is dead on Z37xx series, it may be the TXE processor that will not let it run!

The offsets of the pad configuration registers for the suspend well differs. This is a bit surpricing to me because it breaks compatibility with other Baytrail architectures.

I'm sure I will find more diiferences. Perhaps a list (non in detail of course) of my findings may be useful for others?

Best regards,

B-O

Gabriel_T_Intel
Employee
136 Views

Hello Berth,

Your findings are very important and they will for sure help many people in their projects,

Thanks a lot for sharing them !

Regards,

Gabriel Thomas.

BBerg7
New Contributor I
136 Views

Thank you Gabriel!

I struggle daily with engineering trouble shooting, so if I can help anyone in the process all my efforts would be worthwhile.

Marcelo_M_Intel
Employee
136 Views

Hello B-O,

Your findings are great!

Best regards,

Marcelo

BBerg7
New Contributor I
136 Views

Thank you Marcelo! I will keep on digging.

Currently working on a BIOS for Z3735F and Z3745 architectures. Rewriting some of the MRC code to make it more versatile for handling memory down configurations. Finished with the code yesterday evening and will do test runs today.

By the way, you would help me a lot if you can find documentation about the pad configuration registers. As I have found that at least the suspend well pad configuration registers are at different offsets in Baytrail-T than Baytrail-I, any help I can get sorting this out would be great.

Best regards,

B-O

Marcelo_M_Intel
Employee
136 Views

Hello B-O,

Sorry for the delay, we are searching for this. We will keep you posted.

Best regards,

Marcelo

BBerg7
New Contributor I
136 Views

Thank you Marcello!

I will start working on the differences next week, so I hope you will have found anything by then.

Have a nice weekend!

B-O

Marcelo_M_Intel
Employee
136 Views

Hello B-O,

Thanks, you too have a great weekend!

We will investigate and as soon as we have an update we will let you know.

Best regards,

Marcelo.

BBerg7
New Contributor I
136 Views

Marcelo_M_Intel
Employee
136 Views

Hello B-O,

Unfortunately the BayTrail Z3745 Bay Trail -T is on the "off-roadmap" and its support is for limited manufacturers. For this reason, we do not have support for this processor.You should be working with an ISV, if not you may need to get support thru the codec vendor (TI). That is of course if your schematic and layout are correct.

I will request to upload some documents that may help you and I will let you know as soon as they are available.

Best regards,

Marcelo.

idata
Community Manager
136 Views

Here is a comparison chart for Z3745x products: http://ark.intel.com/compare/80270%2c80271 ARK | Compare Intel® Products. As Marcelo states, there are not embedded skus. The long-life skus/specifications can be found here: http://www.intel.com/content/www/us/en/embedded/products/bay-trail/specifications.html Intel® Atom™ processor E3800 Product Family: Specifications. Hope this helps.

-Scott

Marcelo_M_Intel
Employee
136 Views

Hello B-O,

Here you have one document, the other is taking longer than expected.

Intel® Atom™ Processor Z3600and Z3700 Series based Android*PlatformMessage of the Week (MOW)

http://www.intel.com/content/www/us/en/secure/embedded/nda/products/bay-trail/atom-z3600-z3700-serie... http://www.intel.com/content/www/us/en/secure/embedded/nda/products/bay-trail/atom-z3600-z3700-serie...

 

As soon as the other one is ready, we will let you know.

 

Best regards,

Marcelo.

BBerg7
New Contributor I
136 Views

Thank you Marcelo!

I will check with ISV if needed.

BBerg7
New Contributor I
136 Views

Thank you Scott! Unfortunately the comparison charts are never detailed enough. For example the CPU core frequency are never in the charts. At least the multiplier should be there, so you can calculate backwards to get the CPU core frequency. Why is that important? Well, the CPU core frequency and other details are part of the SMBIOS data. This kind of information is a headache to find and are required for BIOS development.

Best regards,

B-O

BBerg7
New Contributor I
136 Views

Thank you Marcelo!

This is very useful information!!!

Now I know what I should ask for from the premium support service.

Best regards,

B-O

Marcelo_M_Intel
Employee
136 Views

BBerg7
New Contributor I
51 Views

Thank you Marcelo!

I will look into it.

Best regards,

B-O

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