I installed CoreOS 4 on a new machine recently, and I liked it and want to now install it on my old Mac Pro “trash can”.
I can boot from the USB, but after all of the messages scroll by and it’s ready to clear the screen and give me the prompt, the screen just goes blank.
Is this a known issue on these machines, and is there a workaround? I had no such trouble on an HP Z4 G4.
Oh I bet I have to turn off Secure Boot first…
Some systems end up with a blank screen using the F38 Live Workstation installer. Workaround is to install F36 or F37 and upgrade. You should be able to find a Bugzilla report for this.
Is that true for CoreOS as well as “regular” Fedora? I thought the problem with Fedora 38 was the graphical installer, which CoreOS doesn’t use.
(The Secure Boot thing isn’t it; if that was the problem it wouldn’t get as far as it does.)
I’m not aware of any problems with Fedora CoreOS with the installer and a blank screen.
I think linux now uses kernel modesetting (KMS) graphics for the text console early in the boot sequence. On my iMac, (with
rhgb quiet removed from the kernel command line),
I see a bit of low res console output before the KMS console starts at a higher resolution.
Per Arch Linux Kernel mode setting:
With Kernel Mode Setting (KMS), the kernel is now able to set the mode of the video card. This makes fancy graphics during bootup, virtual console and X fast switching possible, among other things.
The Arch Linux document has pointers to additional details.
Thanks. Yes I do see some text output first, then it goes blank just when a normal boot would issue a login prompt. On the HP machine, at that point it clears the screen and then gives more text mode output in what appears to be the same video mode, but it might not be.
I’ll try the disabling KMS on the command line. No idea why that wouldn’t be disabled on a Live USB installer image that boots to a command line already, though. (Aren’t most people who are installing FCOS on bare metal intending to use it headless anyway?)
Thanks for the pointer.
Closing the loop on this. Hitting
e at the grub menu and adding
nomodeset on the kernel command line fixed this. Thanks!