Here I would like to give instructions on how to create a bootable USB stick from the X5000 installation CD on the AmigaOne X5000/20 with an RX graphics card.

Note:
I accept no responsibility or liability for data loss, hardware damage, etc. Reproducing/following these instructions is at your own risk.

Update 10/10/2024
illustrated pdf guide here: OS4Depot

You will need:
- AmigaOneX5000InstallCD-53.25.iso
- a USB stick, in my case with 4GB
- installed DiskImageDevice
- RadeonRX.chip, RadeonRX.chip.debug from the Enhancer 2.1 package
- a text editor

Step 1:
Go to the Hyperion entertainment website, log in to the user area and download the AmigaOneX5000InstallCD-53.25.iso.lha.
Unpack the ISO file on your computer.

Step 2:
Plug in the USB stick, open MediaToolbox, select "usbdisk.device" and click "Start".
After clicking on "Install" a new window opens, click on "Install/read configuration" and confirm with "Yes", then click on "OK - accept changes". A partition must then be set up.
To do this, click on "Edit partitions and filesystems". In the partition window I changed the name to "UDH2" and reduced the partition size to 1GB.
Now click on "Select filesystem" and select "Long file names" next to "FastFileSystem".
Then click on "Ok - accept changes" twice and you are back at the Media Toolbox.
There then "Save to disk", confirm the query with "Yes, save" and then close the MediaToolBox. This will bring up the message that a restart is required, which is also confirmed with "Yes, restart immediately!"

Step 3:
After the computer has booted up again, the USB stick must be formatted.
We use the same name as on the installation CD, i.e. "AmigaOS 4.1 Final Edition" and then select "Quick Format".
Acknowledge the following confirmation by clicking on "Format".
Now we start DiskImageDevice and select the ISO of the installation CD that we downloaded at the beginning.
We now open the mounted ISO and display the entire contents. Select all files and drag them into the opened window of the USB stick to copy them.
The entire contents of the CD are now transferred to the USB stick.

Step 4:
Now a few things still need to be modified, as the X5000 has an RX graphics card installed and would otherwise "hang" on the AmigaOS boot image.
To prevent this from happening, we first open the Kickstart folder on the stick and open the "Kicklayout" contained therein with a text editor.
Scroll down a bit and where the graphics cards are entered, the following line must be inserted:

MODULE System/Kickstart/RadeonRX.chip

Then save.
The same addition must also be made in the kick layout, which is in the System/Kickstart folder. Here too, add the line:

MODULE System/Kickstart/RadeonRX.chip

to the graphics card entries and save.
Finally, copy the RadeonRX.chip and RadeonRX.chip.debug files to the System/Kickstart folder. Now the "startprefs.bat" file from the "Installation-Support" folder must be adjusted.

There you have to put a semicolon before each line:

:Installation-Support/CheckHardwareCompose
if $RC EQ 0
copy :Installation-Files/GUI-compose.prefs env:sys/GUI.prefs
setenv _INSTALL_HWACCEL 1

and it should then look like this:

;:Installation-Support/CheckHardwareCompose
;if $RC EQ 0
;copy :Installation-Files/GUI-compose.prefs env:sys/GUI.prefs
;setenv _INSTALL_HWACCEL 1

This completes the modification.

Step 5:
To finalize the boot stick, it has to be made bootable in the last step.

To do this, we open the MediaToolbox again, select the stick and under Edit Partitions we now tick "Bootable" and set the "Boot priority"
e.g. to "5" and save the whole thing.
The boot priority of the USB stick must definitely be higher than that of the actual boot hard drive so that the stick is automatically found and booted from it.
Now perform a cold start with the boot stick plugged in and then the
AmigaOne X5000/20 with RX graphics card should boot from the stick without any problems.

Additional tip for the X5000/40:
The file "ehci.usbhcd" should be replaced with the version from the AmigaOS 4.1FE Update2 archive, otherwise the mouse and keyboard may not work.

Finally, I would like to thank "khayoz" and "Spectre660" from the amigans.net forum for their helpful tips.