Uncategorized

Updated 22 November, 2021

Recently, I repurposed an old desktop machine to be a headless server for running machine learning and ArchiveTeam stuff. In its former life it ran Manjaro alongside Windows 10, so I figured I might as well stick with Manjaro in its new role.

Of course, since it would be running headless, I needed to install a remote desktop solution. xrdp has worked a treat in the past on my various other Debian-based systems, so what the heck.

Unfortunately, a quick Google search will confirm that running xrdp on Manjaro is anything but straightforward. The issues are twofold:

1. A required package has a borked GPG signature, so you have to build it yourself.
2. Even once you have all the dependencies installed, you’re greeted by a blank screen.

Fortunately, the solution is relatively straightforward. So without any further prologue, let’s go.

Note: XFCE

I’m assuming that your desktop environment is XFCE, since that’s the default Manjaro environment. If you’re using KDE or Gnome, I’m guessing the same steps apply. But don’t take my word for it.

Step 1: SSH into your machine

Since this is a headless machine, I’m doing everything via SSH. That said, other than Step 2, everything will be via the terminal anyway.

Step 2: Install some dependencies

Specifically, we’re going to install:

• yay – which enables the installation of AUR packages. xrdp doesn’t live in the regular pacman universe, so we need yay.
• base-devel – which enables the building of said AUR packages
• xorg-xserver-devel – which provides necessary dependencies for xrdp.
• xorg-server-dev – successor xorg-server-devel. Provides necessary dependencies for xrdp.

sudo pacman -Sy yay base-devel xorg-xserver-devel

Step 3: Install xrdp

Now we can install xrdp using yay.

yay -S xrdp

Agree to install all dependencies, blah blah, and you’re good.

Step 4: Download and install xorgxrdp

Normally, we’d install xorgxrdp through yay, same as xrdp. Unfortunately, the GPG keys are scuzzed up, so we have to do this the hard way: by building it ourselves.

Fortunately, this isn’t hard at all.

Step 4a: Download xorgxrdp

As of this writing, the latest release is 0.2.17. Find the current link on the AUR page under Sources and proceed accordingly.

wget https://github.com/neutrinolabs/xorgxrdp/releases/download/v0.2.17/xorgxrdp-0.2.17.tar.gz

Step 4b: Extract the files and enter the directory

tar xvf xorgxrdp-0.2.17.tar.gz
cd xorgxrdp-0.2.17

Step 4c: Configure, make, and install

./bootstrap
./configure
make
sudo make install

Step 5: Create (or edit) your Xwrapper.config file

My understanding of this step is sketchy, but it goes like this: by default, X11 won’t open a session unless you’re at the display. This is understandably an issue if you’re remote.

So we either edit /etc/X11/Xwrapper.config (if it exists) or create a fresh copy (most likely the case), containing the ending (or only) line:

allowed_users = anybody

Step 6: Edit ~/.xinitrc

This is the file that is causing your blank screen woes, and likely why you’re reading this post in the first place. The stock version has a couple of typos that result in the window manager never actually being invoked. In particular, we need to make 3 edits:

1. Change SESSION=${1:-xfce-session} to read SESSION=${1:-xfce4-session}
2. Change local dbus_args=(–sh-syntax –exit-with-session) to read local dbus_args=(–sh-syntax)
3. Change exec $(get_session “$1”) to read exec $(get_session “$SESSION”)

The resultant file should look like

#!/bin/bash
#
# ~/.xinitrc
#
# Executed by startx (run your window manager from here)

userresources=$HOME/.Xresources
usermodmap=$HOME/.Xmodmap
sysresources=/etc/X11/xinit/.Xresources
sysmodmap=/etc/X11/xinit/.Xmodmap

SESSION=${1:-xfce4-session}

# merge in defaults and keymaps

if [ -f $sysresources ]; then
    xrdb -merge $sysresources
fi

if [ -f $sysmodmap ]; then
    xmodmap $sysmodmap
fi

if [ -f "$userresources" ]; then
    xrdb -merge "$userresources"
fi

if [ -f "$usermodmap" ]; then
    xmodmap "$usermodmap"
fi

# start some nice programs

if [ -d /etc/X11/xinit/xinitrc.d ] ; then
    for f in /etc/X11/xinit/xinitrc.d/?*.sh ; do
        [ -x "$f" ] && . "$f"
    done
    unset f
fi

get_session(){
        #local dbus_args=(--sh-syntax --exit-with-session)
        local dbus_args=(--sh-syntax)
        case "$1" in
                awesome) dbus_args+=(awesome) ;;
                bspwm) dbus_args+=(bspwm-session) ;;
                budgie) dbus_args+=(budgie-desktop) ;;
                cinnamon) dbus_args+=(cinnamon-session) ;;
                deepin) dbus_args+=(startdde) ;;
                enlightenment) dbus_args+=(enlightenment_start) ;;
                fluxbox) dbus_args+=(startfluxbox) ;;
                gnome) dbus_args+=(gnome-session) ;;
                i3|i3wm) dbus_args+=(i3 --shmlog-size 0) ;;
                jwm) dbus_args+=(jwm) ;;
                kde) dbus_args+=(startplasma-x11) ;;
                lxde) dbus_args+=(startlxde) ;;
                lxqt) dbus_args+=(lxqt-session) ;;
                mate) dbus_args+=(mate-session) ;;
                xfce) dbus_args+=(xfce4-session) ;;
                openbox) dbus_args+=(openbox-session) ;;
                *) dbus_args+=("$1") ;;
        esac

        echo "dbus-launch ${dbus_args[*]}"
}

exec $(get_session "$SESSION")

Step 8: Enable and Start xrdp

sudo systemctl enable xrdp
sudo systemctl start xrdp

Step 8.1: Bypass nVidia Drivers

If you’re running nVidia drivers, there’s one more step, which I discovered courtesy of this delightful post.

In short, the nVidia drivers will cause the blank screen to resurface. We want to keep the drivers for use by applications, but deny their use by xrdp. Here’s how:

1. Make the directory /etc/X11/nvidia.d
2. Move the files 90-mhwd.conf and [stuff].nvidia-drm-outputclass.conf to said directory where [stuff] depends on your specific installation. For me the file was 10-amdgpu-nvidia-drm-outputclass.conf but your mileage (and CPU) will vary.

sudo mkdir /etc/X11/nvidia.d
sudo mv /etc/X11/xorg.conf.d/90-mhwd.conf /etc/X11/nvidia.d
sudo mv /etc/X11/xorg.conf.d/10-amdgpu-nvidia-drm-outputclass.conf /etc/X11/nvidia.d

Your /etc/X11 directory should look something like

.
├── mhwd.d
│   ├── nvidia.conf
│   └── nvidia.conf.nvidia-xconfig-original
├── nvidia.d
│   ├── 10-amdgpu-nvidia-drm-outputclass.conf
│   └── 90-mhwd.conf -> /etc/X11/mhwd.d/nvidia.conf
├── tigervnc
│   └── Xsession
├── xinit
│   ├── xinitrc
│   ├── xinitrc.d
│   │   ├── 40-libcanberra-gtk-module.sh
│   │   ├── 50-systemd-user.sh
│   │   └── 80xapp-gtk3-module.sh
│   └── xserverrc
├── xorg.conf.d
│   └── 00-keyboard.conf
├── xrdp
│   └── xorg.conf
└── Xwrapper.config

Step 9: Prosper

Hop on in, and be greeted by the XFCE environment.

Let me know if you still have any issues, though the chances of my being able to solve them are miniscule. Godspeed!

Normally, my ASUS MB169B USB Monitor lives in my briefcase, to be used when I need two screens at a coffee shop or a client. But, given the new work-from-home reality, it’s found a new life as a dedicated spot for tiles showing email, calendar, and Slack…

…at least it does when I’m running Windows. When running Manjaro, the USB monitor has sat idle, unused, and sad.

That’s not to say that Manjaro doesn’t support the use of DisplayLink to attach USB monitors — it’s just that, like all things Arch Linux, you have to work for it; doubly so if you’re running an nVidia card.

So, here’s how I got mine working.

1. Install DisplayLink and EVDI drivers.

Do you need both? Beats me, but this is what I have and it works. Purists will do this via pacman but I’m lazy and used the GUI.

2. Install the nVidia drivers, even though they’re not very good.

This turned out to be the key step. Normally, I use modesetting as my graphics driver, mainly because it doesn’t suck. With the nVidia drivers, I get some annoying mouse flickering that I haven’t yet been able to address.

However, the USB monitor also uses modesetting, and with both on the same driver, xrandr returns the following when you try to link them up:

X Error of failed request:  BadValue (integer parameter out of range for operation)
  Major opcode of failed request:  139 (RANDR)
  Minor opcode of failed request:  21 (RRSetCrtcConfig)
  Value in failed request:  0x0
  Serial number of failed request:  22
  Current serial number in output stream:  22

What does it mean? No idea.

How do we fix it? Bust out those crap-ass proprietary drivers.

Enter Manjaro Settings Manger, choose Hardware Configuration, and attain the following setup (the video-linux drivers may be optional, but they’re doing no harm so whatev):

3. Enable and configure the DisplayLink service

Per the instructions in the Arch Wiki, enable DisplayLink by typing in the terminal
sudo systemctl enable displaylink.service

Then, create a file at
/usr/share/X11/xorg.conf.d/20-evdidevice.conf
with the contents

Section "OutputClass"
	Identifier "DisplayLink"
	MatchDriver "evdi"
	Driver "modesetting"
	Option  "AccelMethod" "none"
EndSection

Note: It’s entirely possible that this step is obviated by use of the nVidia drivers, but I’m not taking chances.

4. Reboot

Just to make sure.

5. List the displays in xrandr

In the terminal, enter
xrandr --listproviders

With luck, you should see both displays, with their respective drivers:

Providers: number : 2
Provider 0: id: 0x1b8 cap: 0x1, Source Output crtcs: 4 outputs: 7 associated providers: 1 name:NVIDIA-0
Provider 1: id: 0x238 cap: 0x2, Sink Output crtcs: 1 outputs: 1 associated providers: 1 name:modesetting

6. Connect the displays in xrandr

In the terminal, enter
xrandr --setprovideroutputsource 1 0

If you’re lucky, this will mirror your displays. Of course, that’s probably not what you want, so let’s get them extended.

7. Configure Manjaro to extend your displays

Open Display Settings and declare your primary monitor as such (I’ve found that the USB monitor tends to be marked as primary, initially).

Uncheck Mirror Displays for obvious reasons.

Choose a resolution for your USB monitor that makes sense (probably not the same as your big-ass desktop monitor).

8. Have a lovely beverage

Celebrate your success. Or let me know if it failed. I probably can’t help, but hey who knows.