Oke I want it to extend the RAM just like FSMC does on the STM429i..
so in boot it has to expand.... and that the framebuffer can use it
as if it already was there..
I will look into some examples where I can begin.... the 23LC1024 I
will try first.
As Alan mentioned, the serial SRAM driver would be a welcome
addition. However, you cannot use it to "To scale up the free
memory." It does not support random access and cannot be used to
increase the size of the heap you can allocate from.
The STMF429i uses parallel, random access FSMC SRAM, not serial
memory. That is how it is able to extend the free memory. SPI SRAM
will not cut it.
Backing up further...
One thing that I never understood is why you need a framebuffer anyway.
The STM32407 does not support the LTDC or DMA2D so you must be using a
serial interface to the ILI LCD. Why do you need a framebuffer at all?
For Littlevgl? Yes, Littevgl needs a framebuffer. NX does not. It can
rend directly into the serial LCD GRAM.
Performance of the serial LCD is not so great in that case unless you
really crank up the SPI frequency and perform other optimizations.
