I tried installing the regular NVIDIA graphics driver for my RTX 4080 but apparently it won't work while having secure boot enabled. Usually it would need MOK key enrollment for the drivers when secure boot is enabled but apparently the Deepin kernels are built without CONFIG_INTEGRITY_MACHINE_KEYRING, which is the feature that lets the kernel trust MOK-enrolled keys for the driver modules. I did this on Fedora recently and everything has worked as expected. MOK key enrollment for drivers also works perfectly on Ubuntu and vanilla Debian. When trying the MOK key enrollment after rebooting after installing and initializing the key with secure boot enabled I get an error:

"Failed to open \EFI\BOOT\mmx64.efi - Not found

Failed to load image Failed to start MokManager: Not found

Something has gone seriously wrong: import_mok_state() failed: Not found"

Then it boot loops into the same error because apparently it boots through the fallback loader path (\EFI\BOOT), which is missing mmx64.efi (MokManager).

I got out of the boot loop by disabling secure boot in my BIOS, then booting into my bootable Deepin usb stick which I used to install Deepin on my ssd. There I was able to insert the previously initialized password for the MokManager. After that it let me boot again but before rebooting into Deepin on my ssd I reenabled secure boot in my BIOS and then I booted into Deepin on my ssd and it let me boot but still without the working graphics driver (2 of my screens are not being recognised at all and my main screens resolution and refresh rate cannot be changed).

My system:

OS: Deepin 25 x86_64
Host: Z790 Pro RS/D4
Kernel: Linux 6.6.143-amd64-desktop-hwe
Uptime: 27 mins
Packages: 1959 (dpkg)
Shell: bash 5.2.21
Display (default): 2560x1440 @ 93 Hz
DE: Deepin
WM: KWin (X11)
WM Theme: dark/deepin
Theme: deepin-dark [GTK2]
Icons: nirvana [GTK2]
Cursor: bloom
Terminal: deepin-terminal 6.5.37
Terminal Font: Noto Sans Mono (11pt)
CPU: 13th Gen Intel(R) Core(TM) i9-13900K (32) @ 5.80 GHz
GPU: NVIDIA GeForce RTX 4080 [Discrete]
Memory: 5.17 GiB / 62.53 GiB (8%)
Swap: 0 B / 16.00 GiB (0%)
Disk (/): 6.98 GiB / 91.10 GiB (8%) - ext4

I hope this can be fixed in future updates since it is a severe bug.

Greetings from Germany