Frame Reader accessing HPS SDRAM

[Altera_Forum]

Dear all, 

 I am designing a video system, and the rest of the basics are done (video-in through Video for Linux 2 works) as well as the processing itself. (BTW I had to move to kernel 4.7.0 to get USB OTG webcam to work, there were many bugs in the enabling of kernel config parameters).   The problem is: I have tried to use the fpga2sdram access (port 1) in either 32-bit or 64-bit modes. I believe I am configuring the Frame Reader registers correctly. However, it seems that the Frame Reader is not streamed-in with any data.   Does someone have a short ANSI/ISO C example showing how the Frame Reader is initialized (and a framebuffer in SDRAM is created) that executes on the ARMs (Linux user-space)? I also have my framebuffer part which should not be the problem. In addition, I have configured the following    <config name='F2SDRAM_COMMAND_PORT_USED' value='0x0' /> <config name='F2SDRAM_READ_PORT_USED' value='0x0' /> <config name='F2SDRAM_WRITE_PORT_USED' value='0x0' /> <config name='F2SDRAM_RESET_PORT_USED' value='0x0' />   from hps.xml as mentioned in other threads. My u-boot environment variables are as such, I regenerated the preloader image, because changing them interactively with setenv does not work, they get invalidated after each reboot.  This is supposed to take all ports out of reset, no? (The default value for F2SDRA_RESET_PORT_USED is 0xf7f in my system)  Am I missing something else?   I would like to thank you in advance.  Best regards, Nikolaos Kavvadias