Nios II Gen2 core error

I'm pretty sure you can still use the high address bit to request uncached accesses.

You also have to option of using the full 32bit address range and marking a smaller amount uncached (probably the very top).

There is a subtle difference in that writes with the high address bit set will no longer update any resident cache line - so if such a line exists, then when it is written back, the contents will be wrong.

Any sensible code won't be doing that anyway, writes by the hardware/dma have always got lost if there was a cache line.

OTOH if you use alt_remap_uncached() on buffers returned by malloc (etc) then you deserve what you get.

Get the linker script to assign the DPR area address with the high bit set.