FPGA2SDRAM subsystem

[Altera_Forum]

Hello all, 

 I'd like to use FPGA2SDRAM subsystem. Thus i added 2 ports in HPS properties in Qsys (mm read & mm write). I generated preloader and u-boot and put them in mmcblockp3 of my sdcard. From hardware side, i got no problem, i managed to read and write in the sdram (according to signaltap).  My issue is now how to write/read in that sdram from arm? What code should i write? What is the adrdess range?...  By advance,  Thanks  Nicolas

[Altera_Forum]

Hi, 

 the ARM could write the whole RAM connected to the HPS-Side. How to write and read, depends on many factors, such as if you are using Linux, if you need to cache the Memory-Region, etc.  Please be so kind to tell a bit more of your needs.

[Altera_Forum]

Hi,  

 I reached to read/write from the ARM thanks to mmap function. What is "cache the Memory-Region" ? (sorry bit dummy in software)

[Altera_Forum]

The ARM has Caches. In order to the size of the Caches and depending on your needs it could be more efficient to bypass the cache for some data...