DMA Address

i need to physical RAM memory test, in that case i need to skip DMA address,Can you please tell me, how to find out DMA address which is mapped with physical memory and skip that physical address. i am want to add this code into my module.I am using linux 3.12 kernel.

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pettitda over 8 years ago in reply to Former Member +1

If you're serious about testing the physical memory, then you need to do it before Linux is loaded. For example, if you are using uBoot for a bootloader then you would do the memory test there or even…

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0 clem57 over 8 years ago

Using DMESG look for:
Virtual kernel memory layout:
    vector : 0xffff0000 - 0xffff1000   (   4 kB)
    fixmap : 0xfff00000 - 0xfffe0000   ( 896 kB)
    DMA     : 0xfbe00000 - 0xffe00000   ( 64 MB)
    vmalloc : 0xd9800000 - 0xf2000000   ( 392 MB)
    lowmem : 0xc0000000 - 0xd9000000   ( 400 MB)
    pkmap   : 0xbfe00000 - 0xc0000000   (   2 MB)
    modules : 0xbf000000 - 0xbfe00000   ( 14 MB)
      .init : 0xc0008000 - 0xc0047000   ( 252 kB)
      .text : 0xc0047000 - 0xc08cde00   (8732 kB)
      .data : 0xc08ce000 - 0xc095c890   ( 571 kB)
       .bss : 0xc095c8b4 - 0xc0ae4448   (1567 kB)

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0 clem57 over 8 years ago in reply to clem57

Then use https://www.kernel.org/doc/gorman/pdf/understand.pdf to translate
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0 clem57 over 8 years ago in reply to clem57

Then use https://www.kernel.org/doc/gorman/pdf/understand.pdf to translate
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