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

Look at your "Address Map" image. BAR0 has the 256MB DDR mapped from 0x1000_0000 to 0x1FFF_FFFF, and it has the onchip RAM mapped lower in that are, so the BAR region needs to be 2 x 256MB = 512MB.

Many computers will not boot with such large BAR regions. In your case, the BIOS probably did not enable that region.

Start by trying to use a smaller BAR.

The Qsys PCIe bridge is missing a function that most PCI bridges normally have, which is the ability to independently set the BAR size, and the base address of where that BAR maps to. Using this feature, you can normally take a 1MB BAR, and move it anywhere in the PCIe device address map, eg., in your case you would be able to look at the DDR 1MB at a time. This is sufficient for simple testing. Since the final application should use DMA, the use of small BAR regions is not an issue.

Start with a small BAR - even if you think this is not the right solution - since using the small BAR will show you whether or not this is really your problem.

Cheers,

Dave