The xdma-test application performs DMA operations between the BMC and the host. A PCI driver is needed on the host; this is provided in the host/ directory.

Then usally found in /usr/src/kernels/

cd host/
make -C <path to kernel source> M=$PWD

If the existing ast graphics driver is running on the host (check for 'ast' with lsmod) it must first be removed.

To obtain the device name (probably "0002:02:00.0"):

ls /sys/bus/pci/drivers/ast/
echo <device name> > /sys/bus/pci/drivers/ast/unbind
rmmod ast

Then probe our driver:

insmod ast-bmc-pcie.ko

Finally, check dmesg for the host address to use with xdma-test, usually 0x60000000.

Compile the xdma-test under openbmc sdk and copy it to the BMC node. Run the test on BMC node.

xdma-test -a <host address> -p -w -s 4096

The host driver provides a device file to check the target memory space to verify that the transfer went through.

dd if=/dev/ast-bmc-mem of=/tmp/vga bs=1024 count=4; cat /tmp/vga | hexdump -C