AR 65444 Xilinx PCI Express DMA Drivers and Software Guide

This is mostly a dump of AR 65444 as a github repo to track my changes

Changelog

The tag rel20180420 basically includes a straight dump of Xilinx's files

1. You will need to copy the files in the etc directory from their "old deprecated" linux install.

   • I've done this here in the master branch

2. Their install instructions miss a few key components for people that don't understand kernels very well: a. You will after running the sudo make install command from the xdma directory, you will see an output message like:

  INSTALL /home/mark2/git/xilinx/xilinx-dma-driver/xdma/xdma.ko
At main.c:160:
- SSL error:02001002:system library:fopen:No such file or directory: ../crypto/bio/bss_file.c:74
- SSL error:2006D080:BIO routines:BIO_new_file:no such file: ../crypto/bio/bss_file.c:81
sign-file: certs/signing_key.pem: No such file or directory
  DEPMOD  4.15.0-45-generic

 This is OK, nothing to worry about. I think it is because it is an unsigned due to the fact
 that you likely lack a signing key at this point in the development.

b. You might need to issue the command sudo depmod after installing the driver. Technically, it is spwed out during the make install command, but I've found that my kernel wasn't about to find the driver c. You should then install the kernel module with sudo modprobe xdma. To check that it is installed, you can use the dmesg | grep xmod. I have an output that looks like:

[  958.391237] xdma:xdma_mod_init: Xilinx XDMA Reference Driver xdma v2017.1.47
[  958.391242] xdma:xdma_mod_init: desc_blen_max: 0xfffffff/268435455, sgdma_timeout: 10 sec.

3. Unfortunately, the following commands will require you to run

modprobe xdma

on every boot. Kinda annoying. The instructions on the manpage modules-load.d are kinda wrong. You need to add the line xdma t o the file /etc/modules. My file now looks like:

# /etc/modules: kernel modules to load at boot time.
#
# This file contains the names of kernel modules that should be loaded
# at boot time, one per line. Lines beginning with "#" are ignored.

fpga
xdma

You can check that things loaded correctly by issuing the command

<F28>mark2@xps ~
$ systemctl status systemd-modules-load.service
● systemd-modules-load.service - Load Kernel Modules
   Loaded: loaded (/lib/systemd/system/systemd-modules-load.service; static; ven
   Active: active (exited) since Thu 2019-02-07 10:29:49 EST; 9min ago
     Docs: man:systemd-modules-load.service(8)
           man:modules-load.d(5)
  Process: 287 ExecStart=/lib/systemd/systemd-modules-load (code=exited, status=
 Main PID: 287 (code=exited, status=0/SUCCESS)

Warning: Journal has been rotated since unit was started. Log output is incomple

mark2@xps ~
$ journalctl -b _PID=287
-- Logs begin at Mon 2018-10-22 23:39:25 EDT, end at Thu 2019-02-07 10:38:58 EST
Feb 07 10:29:49 xps systemd-modules-load[287]: Inserted module 'lp'
Feb 07 10:29:49 xps systemd-modules-load[287]: Inserted module 'ppdev'
Feb 07 10:29:49 xps systemd-modules-load[287]: Inserted module 'parport_pc'
Feb 07 10:29:49 xps systemd-modules-load[287]: Inserted module 'fpga'
Feb 07 10:29:49 xps systemd-modules-load[287]: Inserted module 'xdma'

Notice that the PID of journalctl command matches the output of the systemctl command.

The command lsmod | grep xdma should also indicate that the module was loaded correctly.

TODO

1. Make the kernel module load automatically depending on a rule from /etc/udev/rules.d
2. Remove that xdma-udev-command.sh script