A 20" 1600x1200 screen in portrait rotated counter clockwise on the left
A 43" 3840x2160 screen in lanscape in the center
Another 20" 1600x1200 screen in portrait rotated clockwise on the right.

Lets just say that on the system login screen (LightDM) the screens are not configured like this, and if you knock your mouse pointer off the center one, it can be surprisingly difficult to get it back, tilting your head sideways and trying to navigate the pointer to the right place.

It also looks cleaner if your login matches the layout you want, so here is how to achieve that.

1.) Configure your screens how you want them in the Display properties settings.

2.) Install and use arandr to create an xrandr string from your preferred layout.

Open a terminal and do the following:

sudo apt update
sudo apt install arandr

Run arandr from the GUI menu:

You should see your screen layout as you have it configured.

If you are happy with it as is, then save it to an xrandr string:

Layout Menu -> Save As

Save it somewhere you know where it is, and name it something nice. I chose to put it on my Desktop and name it "lightdm_xrandr.sh"


3.) Prepare the file containing your xrandr string for use:

The file contained my somewhat semi-complicated xrandr string:

#!/bin/sh
xrandr --output DisplayPort-0 --primary --mode 3840x2160 --pos 1200x0 --rotate normal --output DisplayPort-1 --mode 1600x1200 --pos 0x560 --rotate left --output DisplayPort-2 --off --output HDMI-A-0 --mode 1600x1200 --pos 5040x560 --rotate right

Unless you have the exact screen layout I do, yours will look different.

For good measure I decided to edit it and add an "exit 0" to the end. This is probably not necessary, but it is proper.

sudo nano ~/Desktop/lightdm_xrandr.sh

#!/bin/sh
xrandr --output DisplayPort-0 --primary --mode 3840x2160 --pos 1200x0 --rotate normal --output DisplayPort-1 --mode 1600x1200 --pos 0x560 --rotate left --output DisplayPort-2 --off --output HDMI-A-0 --mode 1600x1200 --pos 5040x560 --rotate right
exit 0

after saving, we should check to make sure it is executable. arandr seems to do this by default, but it doesn't hurt to check:

# ls -l ~/Desktop/lightdm_xrandr.sh
-rwx------ 1 matt matt 263 Oct 22 23:38 lightdm_xrandr.sh

-rwx------ -> Read Write eXecute. Permissions are correct (in Mints default bash config the file should also be listed as green if it is executable)

If it is not executable you can make it so with the following command:

chmod 700 ~/Desktop/lightdm_xrandr.sh

Then move this script to /etc/lightdm

sudo mv ~/Desktop/lightdm_xrandr.sh /etc/lightdm/

So now we have a "script" that sets the proper screen orientation. Now we have to tell lightdm to execute it on startup.

4.) Tell lightdm to execute your xrandr string on boot:

First we have to find the config file. Since the file may differ by version or specific configuration, rather than tell you which file I edited, I will show you how to find yours, just in case yours is different.

Run lightdm --show-config to display the current configuration.

# lightdm --show-config

   
A  allow-guest=false
C  greeter-wrapper=/usr/lib/lightdm/lightdm-greeter-session
D  guest-wrapper=/usr/lib/lightdm/lightdm-guest-session
E  xserver-command=X -core
F  greeter-session=slick-greeter
G  user-session=cinnamon

   
B  backup-logs=false

Sources:
A  /usr/share/lightdm/lightdm.conf.d/50-disable-guest.conf
B  /usr/share/lightdm/lightdm.conf.d/50-disable-log-backup.conf
C  /usr/share/lightdm/lightdm.conf.d/50-greeter-wrapper.conf
D  /usr/share/lightdm/lightdm.conf.d/50-guest-wrapper.conf
E  /usr/share/lightdm/lightdm.conf.d/50-xserver-command.conf
F  /usr/share/lightdm/lightdm.conf.d/90-slick-greeter.conf
G  /etc/lightdm/lightdm.conf.d/70-linuxmint.conf

Look for a config file that says something about "slick greeter". In my case this was:
/usr/share/lightdm/lightdm.conf.d/90-slick-greeter.conf

Edit this file:

# sudo nano /usr/share/lightdm/lightdm.conf.d/90-slick-greeter.conf

By default it should look like this:

greeter-session=slick-greeter

Add this line between and greeter-sessiion as follows:

greeter-setup-script=/etc/lightdm/lightdm_xrandr.sh

greeter-setup-script=/etc/lightdm/lightdm_xrandr.sh
greeter-session=slick-greeter

Reboot. Your login screen should now be oriented the same as your desktop once logged in.

I hope this helps someone else.

i have tried quit a lot, but my dual core G5 2004, is not able to see any files on USB drivers in Open firmware. Image is fine, Linux is it and able to get files list through commands from other storage device fine, but never on USB. im sure about right alias etc.. There is simply not device list usb flashdisk as nothing is connect, only usb keyboard + mouse..

  I suspect that not all USB sticks are compatible, my is Sandisk USB 3. maybe that is the problem. Its 20 GB image, so i not have other so big flashdrives free and its erasing whole disk, what is not ideal for me.
  BTW writing data to flashdrive takes a lot of time because of majority of it its free place to clone it to target.. but im partition resize could be done easily through command added to installer, instead of copying 10 GB of raw data.. or install can create bigger partion from the start and use something more clever than dd.

 So for me it would be much better to have some live / install Dual layer iso, real data are smaller than 8.5.. i know that there is Debian netinstall, but its slow with downloading nad i has broken grub etc.

  I tried to somehow convert USB data to ISO DVD fomat, b make some install iso, proven to be beyond my skils, because USB are using 2 partitions and there some USB specific data it seems and extracting data from img file with 7zip not worked for all the data. 
  Also make new image from already made USB installer, could bypass 7zip extraction problem, but simply copy all data to 1 partition / folder and make iso from its not enough.

I'm trying to get MintPPC up and running on an iMac G5 20" which has a 64MB AGP Geforce FX 5200 Ultra. It needed a couple of hardware repairs and I did initially suspect the graphics issue was hardware related. However everything works perfectly on Mac OS X.

I installed using the live USB method and have updated since. The issue is that soon into boot (I think as soon as the Nouveau driver starts loading) there is spectacular screen tearing. I can use Mint absolutely fine over SSH and VNC. I found another live PPC distro Adelie yesterday (also Debian based I think?) and exactly the same thing happened. I have tried to install various verions of Debian but all failed due to dodgy repos.

There seems to have been issues with the video drivers on this iMac back in 2015 with Kernel 3/4 but any fixes appear to have been added to later kernels.

I have tried everything suggested in this forum and others and I'm totally stumped. I have attached a couple of photos and a short video as well as a dump of the boot log.

May be a lost cause but I'd love to get Mint working on this thing.

Thanks in advance!

Regards,

Kristoffer