I'm trying to understand the technical bit about the nomodeset parameter in the GRUB boot loader. I read the statement below off of an Ubuntu forum ():
"The newest kernels have moved the video mode setting into the kernel. So all the programming of the hardware specific clock rates and registers on the video card happen in the kernel rather than in the X driver when the X server starts"
The way I understood how graphics memory worked is that the BIOS looks after the graphics card and memory. Normally GRUB will pass off this memory to the Kernel because of the $vt_handoff parameter in the bootloader. So what I don't understand from the paragraph above, is what the X driver is (what/who owns it & when it is run)?
1 Answer
nomodeset deactivates Kernel Mode Settings (KMS).
This means that the X Server takes care of the graphics - "X driver" is misleading in my opinion.
The X session is started by your display manager, e.g for GDM:
/sbin/init (root) --> /usr/sbin/gdm (root) --> gdm-session-worker (root) --> /usr/lib/gdm/gdm-x-session (your user)
The X Server or the "kernel" determines the necessary information itself, not a BIOS or something similar.
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