Help: Windows didn't assign Bar0 to PCie (address mapping is not correct)

but will it reduce BAR0 size? I just concern if my computer can boot.

Do you mean using DMA can reduce BAR0 size if the x86 host memory is still connected to Qsys ?

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You need to use slight-of-hand and indirection :)

You need to think of the memory map of your board as being independent/separate to the memory map of your x86 host. If you want to move results between your Qsys memory map and your x86 host memory, then you use DMA. The DMA controller needs to be able to see both PCIe addresses and Qsys addresses to be efficient.

If you use the x86 host to directly read and write to your Qsys system, it will not be very efficient (low data rate). Typically you use (slow) x86 transactions to setup the DMA controller, and then let it perform efficient transfers.

Cheers,

Dave

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