How to use SDRAM for all dynamic memory allocations for stm32f746g discovery board?

[TFilm]

I am using stm32f746g discovery board for my application. Currently the memory allocation is done on SRAM. I would like to use SDRAM for all dynamic memory allocation. I tried changing heap address to sdram address in linker script, but this gives hard fault. Any idea how this is done. A demo example would be really good for better understanding.