Table of Contents
- Grub does not start or otherwise disables my installer
- Installer can't find CD by label
- I can see Grub/Yaboot and systemd starting but then it switches my display off
- I'm using a DVI to HDMI adapter/cable and resolution is out of range
- My GPU seems to switch to the wrong output
- I installed yaboot as a bootloader but it won't be detected bootable by OpenFirmware
Grub does not start or otherwise disables my installer
If you are one of the unfortunate souls that has a machine that cannot start Grub (likely a pre-G4 machine with very little RAM) and the installer doesn't boot or some other issue happens that cannot be pinned on anything else otherwise, you may want to try using Yaboot.
To do this boot into OpenFirmware via Command + Option + O + F.
Then simply manually load the yaboot binary:
boot cd:,\boot\yaboot
This works from installer version 2022.03.24 and later.
While this may fix your immediate issues with booting, Yaboot is obsolete and barely maintained. Move to GRUB at your earliest convenience.
Installer can't find CD by label
If you are seeing a message such as:
ERROR: '/dev/disk/by-label/ARCH_202203' device did now show up after 30 seconds...
and then are dropped to a shell the following may help until this bug has been squashed (CD/DVD only issue).
$ udevadm trigger $ ^-D
I can see Grub/Yaboot and systemd starting but then it switches my display off
This is likely due to firmware issues of your GPU. If you cannot otherwise access your system remotely via SSH for instance you can try the following kernel cmdlines:
nouveau.modeset=0 radeon.modeset=0 radeon.blacklist=1
Then investigate demsg of the failed boot using journalctl to look for possible causes:
journalctl -k -b -1
I'm using a DVI to HDMI adapter/cable and resolution is out of range
If you can see Grub, try the following kernel cmdline for a pretty standard low-res 800x600 at 60hz:
video=800x600@60
If even OpenFirmware doesn't display, insert a MacOS Installer or Reocovery DVD and boot it once. It should set things right. If it keeps resetting to a black screen / out of range mode, check your PRAM battery is carrying a charge.
My GPU seems to switch to the wrong output
For example, it can happen on a G5 with a Gforce 6600LE that nouveau switches over to a phantom output, such as TV-1.
In dmesg this looks something like this:
Feb 20 21:27:25 archpower kernel: nouveau 0000:0a:00.0: DRM: Setting dpms mode 3 on TV encoder (output 4)
You should disable the ports in question and/or force a particular port like in the following example:
video=TV-1:d video=TV-2:d video=DVI-I-2:d video=DVI-I-1:1920x1080@60
The above disables TV output 1 and 2 as well as DVI-I-2, then sets a forced resolution on DVI-I-1.
I installed yaboot as a bootloader but it won't be detected bootable by OpenFirmware
Ensure /boot/yaboot.conf as well as the kernel and initramfs are on a supported filesystem. Safe bets are:
hfs vfat ext2/3/4
btrfs is not supported. You need a seperate partition for /boot using a supported filesystem in this case.