For my application, I want to write from the PRU into a large set of circular buffers in the ARM DDR memory. Following various examples, I have gotten this to work for small amounts of data, but when I attempt to write "too much", I crash the Linux. To me, this is not surprising, as I don't see where the Linux has been warned to set aside the memory region where the data from the PRU will be appearing. Should I be booting with some options like "MEMMAP=" being passed in the kernel parameters? (This is a concept I'm slightly familiar with from the X86 arch). Does anyone have any successful examples of having done this? (Is MEMMAP the way to do it? Or is there perhaps something I need to add to the pruss section of the devtree?)
To add some more details, I've tried expanding the "extram_pool_sz" option when I modprobe in the uio_pruss driver, but get crashes way before I approach the size (which I have verified with a call to prussdrv_extmem_size()). I've looked at the source for the prussdrv side, and for the uio_pruss driver, and don't see where memory is ever reserved or locked down. Also, I've never seen the data at the pointer returned from calling prussdrv_map_extmem, but had to mmap into /dev/mem myself (following examples I found w/ Google). Thanks, Andy S. -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
