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FAQ

Some common Q&As for RockOS.

My AMD RDNA (or newer) GPU isn't working, with Kernel Oops on boot​

This is related to AMD GPUs' PCI-E D3cold.

To solve this, edit /etc/default/u-boot, add the following parameters in U_BOOT_PARAMETERS section:

pcie_port_pm=off pcie_aspm.policy=performance

You can use nano to edit: sudo nano /etc/default/u-boot

After editing, press Ctrl+X and follow the prompts to save, then run sudo u-boot-update.

If you already installed the dGPU, you might not be able to perform a system reboot. You can use SysRq to do a force reboot:

sudo sh -c 'echo 1 > /proc/sys/kernel/sysrq'
sudo sh -c 'echo b > /proc/sysrq-trigger'

I installed a dGPU but the system freezes on boot​

It's very likely that you have insufficient power supply. Please use ATX PSU rather than DC PSU.

According to PCI-E specifications, PCI-E slot requires 75W of power, while using a 12V 5A 60W DC PSU might not be enough, thus causing a boot failure.

No video output on dGPU​

This is because the system is configured to use the Imagination GPU and onboard HDMI output by default.

We need to change the configurations, disable the iGPU and display output, and switch Mesa version.

Like the D3cold workaround above, we can edit /etc/default/u-boot, add the following parameters in U_BOOT_PARAMETERS section:

initcall_blacklist=es_drm_init module_blacklist=pvrsrvkm

You can use nano to edit: sudo nano /etc/default/u-boot

After editing, press Ctrl+X and follow the prompts to save, then run sudo u-boot-update.

The default installed Mesa is specifically for Imagination GPU rather than AMD GPUs, so we'll need to switch versions here:

dpkg -l | grep 22.3.5+1rockos1+0pvr2 | awk '{print $2"=24.2.3-1"}' | xargs sudo apt install --allow-downgrades -y
sudo apt-mark hold libegl-mesa0 libgbm1 libgl1-mesa-dri libglapi-mesa libglx-mesa0 \
mesa-va-drivers mesa-vdpau-drivers mesa-vulkan-drivers mesa-libgallium
sudo cp -vrf /usr/share/xorg/glx/extensions/ /usr/lib/xorg/modules/

Now you can reboot the board. Video output should be on the dGPU now.

I need OpenGL on the integrated Imagination GPU​

You can use Zink for OpenGL.

Run the following commands to enable Zink globally:

sudo cp -vrf /usr/share/xorg/glx/extensions/ /usr/lib/xorg/modules/
sudo sh -c 'echo MESA_LOADER_DRIVER_OVERRIDE=zink > /etc/environment'
sudo systemctl restart lightdm.service

Available RAM less than expected​

You may see less RAM available, e.g. ~9.7GB for 16GB boards, or ~25GB for 32GB boards.

This is due to, part of the RAM is allocated for NPU, video encoder/decoder, etc.

To free up this part of memory, you can change the boot command in U-Boot environment.

warning

NPU, video codec, and other related functions will no longer work after releasing mmz memory.

Do not proceed if you still need these features.

Connect UART serial to your PC. Use tools like minicom, tio, PuTTY to connect.

When prompting Autoboot in 5 seconds, press s to interrupt.

Check the the current bootcmd, just in case:

Autoboot in 5 seconds
=> env print bootcmd
bootcmd=bootflow scan -lb

Change bootcmd to: fdt mmz mmz_nid_0_part_0 0x300000000 0x1000;bootflow scan -lb

=> env set -f bootcmd 'fdt mmz mmz_nid_0_part_0 0x300000000 0x1000;bootflow scan -lb'; env save
Saving Environment to SPIFlash... Erasing SPI flash...Writing to SPI flash...done
OK
=> boot
Added mmz_nid_0_part_0 to reserved-memory node, addr=0x300000000, size=0x1000
Scanning for bootflows in all bootdevs
...(Normal boot process)...

Login and check available system RAM:

debian@rockos-eswin:~$ free -hm
               total        used        free      shared  buff/cache   available
Mem:            31Gi       558Mi        30Gi       4.4Mi       286Mi        30Gi
Swap:             0B          0B          0B

To revert, set bootcmd back to bootflow scan -lb, then env save.