mbedTLS RAM storage Saving by using SPI Flash

Hi There,

I am using the mbedTLS library on an STM32F4 processor.
As I am working now on reducing RAM consumption, I saw your articles about RAM storage-saving possibilities.
I was wondering if there is a way to use SPI Flash for the TLS heap instead of RAM.
My controller has about 120KB of RAM and only the heap currently consumes around 54K.
Of course, I know that it will take more time to perform the connections since the access to the memory is slower but I will afford it at the expense of the RAM saving.