Embedded Intel Atom® Processors
Intel Atom® Hardware, Software, Firmware, Graphics
Announcements
Welcome to the Intel Community. If you get an answer you like, please mark it as an Accepted Solution to help others. Thank you!

E3815 GTT memory allocation

AMamo1
Novice
1,014 Views

Hello!

I'm trying to figure out the order of initialization of the E3815 graphics. I cannot understand whether to allocate memory for Graphics Translation Table. The documentation (# IHD-OS-VLV-Vol5-04.14, page 19) says: "The base address (MM offset) of the GTT and the PPGTT are programmed via the PGTBL_CTL and PGTBL_CTL2 MI registers, respectively." But I can not find the description of the register PGTBL_CTL in the E3800 Datasheet. Also, I looked at the Linux driver (i915) source code and it seems like it doesn't allocate memory for GTT. Hence the question: Do I have to allocate memory for GTT, and if so, how to do it correctly?

0 Kudos
3 Replies
CarlosAM_INTEL
Moderator
140 Views

Hello AlexMamonov ,

Thank you for contacting the Intel Embedded Community.

The information that may help you is stated in the https://01.org/sites/default/files/documentation/intel_os_gfx_prm_vol2_-_cmd_ref_registers_0.pdf Intel® Open Source HD Graphics Programmers' Reference Manual (PRM) Volume 2, Part 3: Command Reference - Registers For the 2014 Intel Atom™ Processors, Celeron™ Processors, and Pentium™ Processors based on the "BayTrail" Platform (ValleyView graphics) document # IHD-OS-VLV-Vol2pt3-04.14.

It is important to let you know that the Intel Open Source Graphics Programmer's Reference Manual (PRM) For The 2014 Intel® Atom™ Processors, Celeron™ Processors, and Pentium™ Processors based on the Bay Trail Platform can be found at the https://01.org/linuxgraphics/documentation/driver-documentation-prms/2014-intel-processors-based-bay... 2014 Intel Processors based on the Bay Trail Platform website.

We hope that this information may help you.

Best Regards,

Carlos_A.

AMamo1
Novice
140 Views

Hello, Carlos.

I looked through document that you mentioned, but I didnt find anything on PGTBL_CTL register or on allocating memory for GTT. Please, could you elaborate in what part of the document should I seek?

Thanks in advance, Alex.

CarlosAM_INTEL
Moderator
140 Views

Hello, AlexMamonov :

Thanks for your reply.

We suggest you address your consultations to the https://01.org/linuxgraphics/forum/graphics-power-users Intel(R) Graphics for Linux* Forum or its https://lists.freedesktop.org/mailman/listinfo/intel-gfx Mailing list.

We hope that this information may help you.

Best regards,

Carlos_A.

Reply