This prevents hard-faults on non-aligned accesses. Reference: http://www.keil.com/support/docs/3777.htm
If SDRAM is configured and enabled for a board then it is used for the MicroPython GC heap.
Taken from 7fbe54ad4e/src/omv/sdram.c Code is is MIT licensed.
7fbe54ad4e/src/omv/sdram.c