Jiff Slater
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23 Apr 2021

[Note] Playing videos on a Raspberry Pi Zero W
15 January 2021

Just a quick note – to play videos on a Raspberry Pi – use omxplayer instead of mplayer for maximum performance.

Configuring Wireguard on the Pinebook Pro in Manjaro Linux
1 February 2020

I recently (Twitter) ordered and received a Pinebook Pro and wanted to share how I got Wireguard working. Wireguard is a VPN that uses modern cryptography while still being easy to configure for various environments.  Unfortunately, even though the kernel module has been merged upstream Manjaro Linux still requires a custom module to be built.  Because the kernel sources aren’t included with the distribution as of now, installing the wireguard-dkms package will fail.  This post shows how I got the userspace wireguard-go program to work in lieu of the kernel module.

Before I continue, if you’re using the default Debian install that came with the device, you should be able to follow this tutorial which uses Cloudflare’s boringtun Rust implementation.  I couldn’t get this tutorial to work so here is an alternative that uses the official Wireguard Go language reference implementation.

Installing the compiler

The Go compiler should be available in all distributions so install it before continuing.  On Manjaro Linux you can do so by typing `sudo pamac install go`.

Cloning the repository

You’ll need to clone to source code from the Wireguard repo: `git clone https://git.zx2c4.com/wireguard-go`.

Building the tool

Once cloning has completed, enter the directory and issue `make`.  After it completes, you should have ./wireguard-go executable in the same directory.

Launching the tool

Open two terminal windows.  In the first, issue sudo LOG_LEVEL=debug ./wireguard-go -f wg0.  This will launch the userspace implementation and create an interface called wg0 which you can see by typing `ip a`.

Configuring and bringing up the Wireguard interface

Bringing up the interface is almost as simple as presented in the docs but because we’re running Manjaro Linux we’ll need to make sure it works well with NetworkManager.  The first step is mark the interface along with any similarly named interfaces as unmanaged.  Create the following file and restart NetworkManager.



# systemctl restart NetworkManager

In a new terminal window, issue the following commands, taking into account your configuration.  Before continuing you’ll also need to have a valid /etc/wireguard/wg0.conf that uses `wg` syntax not wg-quick syntax.  Check the manpage for wg to confirm.  Note that CLIENT_IP_ADDRESS and PEER_IP_ADDRESS_OR_RANGE refers to the address Wireguard interface address space.

# ip address add dev wg0 CLIENT_IP_ADDRESS peer PEER_IP_ADDRESS_OR_RANGE
# wg setconf wg0 /etc/wireguard/wg0.conf
# ip link set mtu 1420 up dev wg0
# ip route add PEER_IP_ADDRESS_OR_RANGE dev wg0

Finally, as per Thaller’s post on the GNOME blogs, if you don’t issue the last command we’ll need to let NetworkManager know about the new route.  List your current connections with nmcli conn show and copy the UUID for your current connection below.  Replace GATEWAY and WIREGUARD_ENDPOINT with the actual IP addressses.

nmcli connection modify UUID +ipv4.routes "WIREGUARD_ENDPOINT/32 GATEWAY"

This should be sufficient to set up the VPN.  You’ll see the handshake initiated and completed in the other terminal window.

Let me know if this worked for you.  DNS resolution is still problematic because NetworkManager doesn’t adjust resolvconf to accomodate the new route.  If you manage to get that working correctly, please let me know on Twitter.

ifconfig Output on macOS Mojave
28 November 2018

ifconfig is a venerable tool that’s been around since 2008, according to the manpage on macOS. If you have a recent device, you’ll discover a much larger number of devices than on Linux.

Here’s the simplified output from my computer.

$ ifconfig | sed -E 's/[[:space:]:].*//;/^$/d' | sort

Let’s walk through them individually.

lo0 is the loopback interface. This is used for the machine to refer to itself.

gif0 is the software network interface.

stf0 is the IPv6 to IPv4 interface.

gif0 is a tunnel interface for IPv4 to IPv6.

p2p0 is airdrop.

en0 is the WiFi interface.

en1 through en4 are the Thunderbolt interfaces, first through fourth.

bridge0 is the Thunderbolt bridge. typically for transfering files over cable between two Macs.

awdl0 is the Apple Wireless Direct Link, typically used for Hotspot functionality with iOS devices and your Apple computer.

ap1 is probably related to the above but I can’t confirm.

en5 is iBridge adapter for the TouchBar.

utunN are related to the sharing of information between devices on the same iCloud account. They can also be created by any VPN interfaces you’ve added.

XHC20, XHC0, XHC1, and VHC128 are something I’ve never seen before with an ifconfig output. I assume they are related to USB controllers. Let’s look at the IOUSB registry plane for more details.

$ ioreg -p IOUSB
+-o Root [...]
 +-o AppleUSBVHCIBCE Root Hub Simulation@80000000 [...]
 +-o AppleUSBXHCI Root Hub Simulation@14000000 [...]

Here we can see two virtual USB hub simulators.

On the first, a simulated virtual USB Host Controller Interface, we can see many iBridge devices connected, including the display, ambient light sensor, camera, microphone, keyboard/trackpad, and something called a DFR brightness. The closest related acronym I could find was digital feedback reducer. In any case, all the Apple devices are exposed via this virtual USB hub. The address of the AppleUSBVHCIBCE is 128 so that explains the VHC128 interface on the ifconfig output.

On the second, an eXtensible Host Controller Inteface (HCI) for Universal Serial Bus (USB), will show any devices you have connected via the ports on your Mac. If we dig deeper into the AppleUSBHostController,

$ ioreg -w0 -rc AppleUSBHostController

[… output truncated …]

We can see one AppleIntelCNLUSBXHCI client which shares the same PCI bus with the four AppleUSB20XHCITypeCPort clients. Furthermore, we can see two AppleUSBXHCITR , each of which having two of the AppleUSB30XHCITypeCPort class, likely the USB 3.0 controllers. Important to note is that the addresses of the clients with the AppleUSBXHCITR class: XHC1@14, XHC2@00, and XHC3@01, giving us the three devices we see in the ifconfig output: XHC20, XHC0, and XHC1, if you we take the high byte from the addresses. It’s likely the numbers after XHC are their sequential locations on the bus.

From these we can conclude that these are merely the USB debugging interfaces, both for the internal clients and external clients.

Using ioreg to dig deeper into the relationship between entities wasn’t as easy as I’m used to on Linux by using lsusb. This leads me to believe that perhaps ioreg is deprecated and there’s a better utility available or some of this information is not exposed completely in publically available tools.

In any case, knowing the source of these interfaces certainly leaves me less perturbed.












Budget Intel Gaming Rig ($500)
25 June 2009

Recently I built my first gaming rig (also my first PC build) with a measly
budget of $500.

The specs:

  • Case: Antec 300
  • CPU: Intel Pentium E6300 Wolfdale
  • PSU: Antec EA650 650W
  • GPU: Sapphire Radeon HD 4830
  • HDD: Western Digital Cavier SE 320GB
  • Mobo: Gigabyte GA-G31-ES2l LGA 775 Intel µATX
  • RAM: OCZ SLI-Ready 240-pin DDR2 SDRAM DDR2 800

Everything was purchased from Newegg and thanks to a couple combo discounts this build was less than $500 including shipping and applicable tax. It was a tough decision. For example, I switched from a NVIDIA GeForce 9800 GT to a NVIDIA GeForce 8600 GTS, finally settling with a AMD Radeon HD 4830. Fortunately, most of the components are overclockable; with the addition of an aftermarket cooler, I will be flying in no time. As an added bonus, the CPU supports VT which will come in handy for running paravirtualised guests under Linux and Windows XP under Windows 7.

Some thoughts for the future: In the next build, the OCZ memory will be replaced by the Corsair XMS brand and I’m definitely going to consider the Antec Sonata III case.

Update: My build is complete! Although I haven’t installed Linux on it yet, I do get a WEI score of 5.5 (highest is 5.9). I’m quite impressed with the performance of this build as well as the ventilation of the case. Temperatures range from the low thirties (celsius) (for both the CPU and the GPU) under a light load to no higher than 50 degrees for a high load.

Arch Linux and the HP Compaq 2710p
28 October 2008

I recently received a HP Compaq 2710p and I’m quite surprised by the performance of this convienent tablet.

After using it for a few weeks, I can say that it works well with GNU/Linux (Arch Linux in particular).  There are a few issues, however:

  • Use of the stylus occasionally conflicts with the default mouse.
  • Brightness of the screen is fixed (unchangeable) upon resume from suspend (both from disk and RAM).

Here is some information about the devices within the computer.

[antony@ARCH ~]$ lspci
00:00.0 Host bridge: Intel Corporation Mobile PM965/GM965/GL960 Memory Controller Hub (rev 0c)
00:02.0 VGA compatible controller: Intel Corporation Mobile GM965/GL960 Integrated Graphics Controller (rev 0c)
00:02.1 Display controller: Intel Corporation Mobile GM965/GL960 Integrated Graphics Controller (rev 0c)
00:19.0 Ethernet controller: Intel Corporation 82566MM Gigabit Network Connection (rev 03)
00:1a.0 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #4 (rev 03)
00:1a.1 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #5 (rev 03)
00:1a.7 USB Controller: Intel Corporation 82801H (ICH8 Family) USB2 EHCI Controller #2 (rev 03)
00:1b.0 Audio device: Intel Corporation 82801H (ICH8 Family) HD Audio Controller (rev 03)
00:1c.0 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI Express Port 1 (rev 03)
00:1c.1 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI Express Port 2 (rev 03)
00:1c.2 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI Express Port 3 (rev 03)
00:1d.0 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #1 (rev 03)
00:1d.1 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #2 (rev 03)
00:1d.2 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #3 (rev 03)
00:1d.7 USB Controller: Intel Corporation 82801H (ICH8 Family) USB2 EHCI Controller #1 (rev 03)
00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev f3)
00:1f.0 ISA bridge: Intel Corporation 82801HBM (ICH8M-E) LPC Interface Controller (rev 03)
00:1f.1 IDE interface: Intel Corporation 82801HBM/HEM (ICH8M/ICH8M-E) IDE Controller (rev 03)
02:09.0 FireWire (IEEE 1394): Ricoh Co Ltd R5C832 IEEE 1394 Controller (rev 05)
02:09.1 SD Host controller: Ricoh Co Ltd R5C822 SD/SDIO/MMC/MS/MSPro Host Adapter (rev 22)
02:09.2 System peripheral: Ricoh Co Ltd R5C843 MMC Host Controller (rev 12)
10:00.0 Network controller: Intel Corporation PRO/Wireless 4965 AG or AGN Network Connection (rev 61)

[antony@ARCH ~]$ lsusb
Bus 007 Device 001: ID 1d6b:0002
Bus 002 Device 001: ID 1d6b:0001
Bus 006 Device 001: ID 1d6b:0001
Bus 004 Device 003: ID 0461:4d17 Primax Electronics, Ltd
Bus 004 Device 002: ID 08ff:2580 AuthenTec, Inc.
Bus 004 Device 001: ID 1d6b:0001
Bus 005 Device 001: ID 1d6b:0001
Bus 003 Device 004: ID 049f:0081 Compaq Computer Corp.
Bus 003 Device 003: ID 04b4:6560 Cypress Semiconductor Corp. CY7C65640 USB-2.0 "TetraHub"
Bus 003 Device 001: ID 1d6b:0002
Bus 001 Device 004: ID 03f0:171d Hewlett-Packard
Bus 001 Device 001: ID 1d6b:0001 
[antony@ARCH ~]$ uname -a
Linux ARCH 2.6.27-rc9 #2 SMP PREEMPT Thu Oct 9 00:58:03 EDT 2008 i686 Intel(R) Core(TM)2 Duo CPU U7600 @ 1.20GHz GenuineIntel GNU/Linux
[antony@ARCH ~]$ df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda5              15G  2.3G   12G  17% /
none                 1009M     0 1009M   0% /dev/shm
/dev/sda2              92M   15M   73M  17% /boot
/dev/sda6              15G  1.3G   13G  10% /home

I’ve kept the system relatively lightweight. Some applications that work well with this computer are:

  • mutt: imap gmail access
  • audacious: music
  • pidgin: instant messenger
  • wget: download manager
  • uxterm: terminal
  • firefox: browser
  • dosbox: games
  • dwm: window manager
  • bash: shell
  • netcfg: network manager

This computer is really convienent to carry around because it is so lightweight.  Soon, I will upgrade to Xorg 7.4 and see if the wacom driver has improved.

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© 2008 to 2020 Antony Jepson