Hi Stephen,

   Get the MemoryMap using GetMemoryMap function calls  and run the memory test 
, where the memory type belongs to "EfiConventionalMemory" type. Other memory 
type regions are used for the different purpose. Please check EFI_MEMORY_TYPE 
and table 25 in the UEFI Spec.

Thanks,
Ramesh

-----Original Message-----
From: Kinney, Michael D [mailto:michael.d.kin...@intel.com] 
Sent: Saturday, January 25, 2014 12:14 AM
To: edk2-devel@lists.sourceforge.net
Subject: Re: [edk2] DMA memory regions and device behavior

Stephen,

A memory stress test can only be run on memory regions that are allocated using 
AllocatePages() or AllocatePool().

Drivers that use DMA will allocate memory for the DMA buffers.  Those buffers 
show up in the EFI Memory Map through the GetMemoryMap() API as allocated 
regions.

Best regards,

Mike

-----Original Message-----
From: Stephen Polkowski [mailto:step...@centtech.com]
Sent: Friday, January 24, 2014 9:56 AM
To: edk2-devel@lists.sourceforge.net
Subject: [edk2] DMA memory regions and device behavior

UEFI gurus,

        Does UEFI have an api for querying the DMA regions in the memory 
system?  I would like to know where they are.
I need to write a memory stress test shell application.
The application will need to read/write all the DRAM with patterns.

        I am worried that it will hit a usb or network buffer while a DMA is in 
progress.  Can I assume that there will be no DMAs until I make a read or write 
call to a UEFI device?

        To put it another way, if my application is running in it's own code 
segment, can I assume that their are no DMAs happening simultaneously?

Thanks for your help.


Stephen


--
Stephen Polkowski
Centaur Technology
Austin, TX
(512) 418-5730

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