Issue with i9-10900TE while activating PAE on linux kernel

[oartigues]

Hi,

I've to compile a linux 32b kernel 5.15.86 RT56 for running on 2 different computers with Intel CPUs : an i7-9700 with 32Gb RAM and an i9-10900TE with 64 Gb RAM.

I need to activate the support of 64Gb of RAM (CONFIG_HIGHMEM64G=y) + PAE (Physical Address Extension) Support (CONFIG_X86_PAE=y)

Once the linux kernel is compiled, it is working correctly on the i7-9700 CPU computer. No issue there.

But impossible to start it on the i9-10900TE CPU computer : black screen at startup without any keyboard, nothing). Linux kernel community is saying that such a result occurs when the CPU is not PAE compatible...

I've checked on the Intel description of the Intel i9-10900TE where PAE compatibility is set.

If I disable the PAE (Physical Address Extension) Support (CONFIG_X86_PAE=n) and set support of 4Gb of RAM instead of 64Gb (CONFIG_HIGHMEM4G=y), then the i9-10900TE CPU computer is starting correctly using the compiled linux 32b kernel 5.15.86 RT56, but with limited RAM support which is not what I'm expected.

Could you please tell me why it is not possible to enable 64Gb of RAM (CONFIG_HIGHMEM64G=y) + PAE (Physical Address Extension) Support (CONFIG_X86_PAE=y) on an i9-10900TE cpu ?

Best regards

[CarlosAM_INTEL]

Hello,  @bsan83:

Thank you for contacting Intel Embedded Community.

We want to address the following questions to understand this situation:

Could you please clarify if this request is related to the Intel® Core™ i9-10900TE Processor design developed by you or is a design developed by a third-party company?

What is the name of the manufacturer, the part number, and where we can find the information if this request is related to a third-party design?

Could you please let us know the Operating System (OS) related to this situation and its version?

We are waiting for your answer.

Best regards,

@CarlosAM_INTEL.

[oartigues]

Hello,

Thanks for your answer.

The computer used in this case is a model SCH-X403 designed by Perfectron for our company (Schneider Electric). It is using this Intel i9-10900TE CPU.

Perfectron is a Taiwanese company with Intel partnership. 

Regarding the operating system we are using, it is a Xubuntu 18.04.05 LTS 32 bits, on which we are putting a kernel 5.15.x RT that I'm compiling by myself. In this case a 5.15.86 RT56 kernel version.

I did a mystake in my initial post : the other model which is working with such a kernel using the same operating system is not an i7-9700 but an i7-9700TE CPU, mounted within a Perfectron model SCH-3X1 also designed for our company.

I hope this can help you, do not hesitate if more is needed,

Best regards

[oartigues]

Please find as an attachement the .config file used for the linux kernel compilation.

Perhaps you can "easily" identify if there is a wrong parameter on it for this issue...

Best regards

[CarlosAM_INTEL]

Hello, @oartigues:

Thanks for your replies.

You should address as a reference your consultations of this type through the channel mentioned at the following website:

https://ubuntu.com/support/community-support

This suggestion is based on the information related to the OS mentioned by you stated in the supported operating systems section of the following website:

https://www.intel.com/content/www/us/en/products/platforms/details/comet-lake-s.html

Best regards,

@CarlosAM_INTEL.