wickiup / xdma-test

xdma-test

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.

Setup

1) Install kernel sources (depends on linux distro)

Then usally found in /usr/src/kernels/

2) Compile driver

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

3) Make sure to enable VGA device on BMC

4) Probe driver

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.

5) Use xdma-test

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

6) Verify

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