Xubuntu 26.04 LTS: Boot Issue Fix (iMac 21" Mid 2011) This guide fixes an issue where the iMac freezes during boot into the command-line interface (TTY1). The problem is caused by timing conflicts between the Radeon HD 6500/6600/6700M graphics card and the display manager.
1. Configure the GRUB Bootloader Open the GRUB configuration file: sudo nano /etc/default/grub Replace or update the lines to match the following GRUB_DEFAULT=0 GRUB_TIMEOUT_STYLE=hidden GRUB_TIMEOUT=5 GRUB_RECORDFAIL_TIMEOUT=1 GRUB_DISTRIBUTOR=$(lsb_release -i -s 2> /dev/null || echo Ubuntu) GRUB_CMDLINE_LINUX_DEFAULT="quiet splash radeon.modeset=1 radeon.runpm=0 amdgpu.modeset=0" GRUB_CMDLINE_LINUX="" Save and exit the file. Update the GRUB configuration: sudo update-grub (Optional) If you need to install or reinstall GRUB to the drive, run: sudo grub-install /dev/sda 2. Fix the LightDM Display Manager Force the login screen to wait until the graphics drivers have fully loaded. Open the LightDM configuration file: sudo nano /etc/lightdm/lightdm.conf Add the following line directly under the [LightDM] section: logind-check-graphical=true Save and exit the file. 3. Force Early Load for Radeon Driver (Dracut) Force the Radeon driver to load at the very beginning of the boot process. Create and open a new configuration file: sudo nano /etc/dracut.conf.d/radeon.conf Add the following line to the file: force_drivers+=" radeon " Save and exit the file. Regenerate the initial ramdisk images for all kernels: sudo dracut -f --regenerate-all 4. Reboot the SystemRestart your computer to apply the changes: sudo reboot -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2152557 Title: Xubuntu 26.04 LTS boot issue To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+bug/2152557/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
