Ubuntu 20.04双系统部署后无法进入BIOS，无法切换至Linux Gecko系统的解决方案求助

Hey there, let's work through this problem step by step. I get that you're stuck booting only into Ubuntu, can't access the BIOS (since pressing F2 hangs on the Acer logo), and need to either switch to Linux Gecko or fully remove Ubuntu. Here's what you can try:

一、先解决BIOS/启动菜单访问问题 #

The root issue here is being locked out of BIOS, so let's fix that first:

• Try a different key press method: Instead of holding F2 nonstop, try rapidly tapping F2 right as you turn on the computer—before the Acer logo appears. Some laptops are finicky about this; holding the key down can cause the boot process to hang.
• Test the F12 boot menu shortcut: Many Acer laptops use F12 to bring up a direct boot selection menu (no need to enter BIOS). Tap F12 repeatedly on startup to see if you can pick Linux Gecko or your bootable USB directly.
• Reset CMOS to restore default BIOS settings: If the above fails, resetting the CMOS can clear any misconfigured boot settings:
  1. Shut down completely, unplug the power adapter, and remove the laptop battery (if it's removable).
  2. Hold the power button down for 30 seconds to discharge static.
  3. Reinsert the battery, plug in the adapter, and try F2 or F12 again on startup.

二、从Ubuntu内部修复GRUB，切换到Linux Gecko #

Since you can boot into Ubuntu normally, we can fix the GRUB boot menu to show your Linux Gecko installation:

1. Open the terminal (press Ctrl+Alt+T), then run this command to scan for all installed operating systems and update GRUB:

   sudo update-grub
   

2. Restart your computer—you should now see the GRUB menu with an option for Linux Gecko. Select it to boot into the system.

三、彻底卸载Ubuntu，保留Linux Gecko #

If you want to remove Ubuntu entirely, follow these steps once you can access Linux Gecko:

1. Open the terminal in Linux Gecko, install the GParted partition tool (if it's not already installed):

   sudo apt install gparted
   

2. Launch GParted, locate the Ubuntu partitions (they'll typically be in ext4 format—you can identify them by size or your original installation choices). Right-click these partitions and select "Delete".
3. Repair Linux Gecko's boot loader to make it the default:

   sudo grub-install /dev/sda
   sudo update-grub
   

   Note: /dev/sda is your main hard drive. If you have multiple drives, double-check the correct device name to avoid mistakes.
4. Restart your computer, and it will boot directly into Linux Gecko with Ubuntu completely removed.

备注：内容来源于stack exchange，提问作者Elgin Cahangirov