Hi Emil,
i.MX6DualLite and Solo SABRE SD share the same HW evaluation board.
i.MX6 Dualite has up to 64-bit DDR interface and i.MX6 Solo has up to 32-bit DDR interface.
If you emulate an i.MX6 Solo on a Dualite SABRE SD board, you'll be forced to use half of the DDR packages of the board as you'll only have a 32-bit DDR interface (instead of 64-bit) consequently you'll divide the memory size of the board by 2.
Anyway 512MB is not the max DDR size of i.MX6 Solo (4GB max).
Application note AN4397 explains that: http://cache.freescale.com/files/32bit/doc/app_note/AN4397.pdf?fpsp=1&WT_TYPE=Application%20Notes&WT...
Bixente