I've been trying to figure out how the dual-plane flash is supposed to be used on the SAM3U4 and wondering if someone can shed some light on this.

The two flash banks are not contiguous and seemingly not intended for use as one large application (as mentioned in another thead). Then the GPNVM bits ability to control which bank is executed on reset tends to suggest that it's suitable for bank-switching two applications.

Is there a way to virtualize the two flash planes? Otherwise an application has to be linked for a specific bank which is not particularly suitable for switching between two versions of the same application.

Hi,

a late answer but here it is

Is there a way to virtualize the two flash planes?

Yes. Due to mirroring effect (128K mirror) of the internal flash 0.

so if you consider 0xE0000 as "virtual" start address for flash 0, you will see the the 2 blocks as contiguous memory.

Regards.