need advice on howto access memory from fpga and cpu

srinivas bakki srinivas.bakki at gmail.com
Wed Oct 30 10:45:08 EDT 2013


If you don't want dynamic memory allocation for framebuffer and neither do
you want it in the user space, All you need is to pass
memmap = <size>$<start address> to the kernel and then write  a kernel
module module where you ioremap that physical address space.

This is just like any other device driver where device registers are mapped.


On Wed, Oct 30, 2013 at 7:56 PM, Kai <kai at kunfoo.org> wrote:

> On Wed, Oct 30, 2013 at 04:20:30PM +0530, srinivas bakki wrote:
> > But otherwise am wondering why would you need to tell the FPGA these
> > kernel mapped addresses ? How is it connected to the memory module ?
>
> The FPGA seems to have direct access to the memory. If I would allocate
> memory for the framebuffer dynamically, I would first have to find out
> the physical adress of this area, and then tell it to the FPGA, so it
> can read the frames from there. We are implementing a "GPU" on the FPGA
> here, or at least something that's reading frames from the RAM, to send
> it to the VGA port.
> --
> Grüße, Kai
>
> "In a world without walls and fences, who needs Windows and Gates?"
>
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