Curious if anybody can tell me how to access external memory from within a linux application?
I am using an AM1808 processor with DaVinci-PSP-SDK-03.21.00.04. We have configured our FPGA at chip select 5.
In googling this, I see some posts asking if mmap() sys call should be used to access FPGA. Originally I tried accessing the memory location as follows:
#define FIFO_BASE 0x66000000
#define FIFO_CHAN1 *(unsigned short*) (FIFO_BASE + 0x00)
void testFunc()
{
FIFO_CHAN1 = 0x5555;
}
The problem....when I compile this application and download the uImage to my board...upon running my application, I receive the following error:
"Unable to handle kernel paging request at virtual address 66000000" followed by a register dump.
Can someone suggest the appropriate way I should be accessing external memory in code? I know u-boot has the "mw" command to write directly to memory...but what can I use within my custom application?
Any help would be appreciated!