Having trouble dual-booting with TPM 2.0?

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I posted elsewhere on the forum that I had successfully managed to dual-boot my youngest's machine with Q4OS alongside Windows 11 (24H2). Since installation of TPM 2.0 chip it is no longer bootable and disabling TPM in the BIOS does not help. A friendly helper on the Q4OS forum gave me this link which I am now sharing with you:

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I needed to update this info. I ran Boot repair and the issue is actually related to NVRAM locked due to Debian x64.efi missing. I've read elsewhere that there is a way to do this but could lead to data loss so you would need to backup your data before attempting it.

As Zorin is Ubuntu based I used Brave A.I. search via mojeek as youngest's PC is Debian based. It came back with:

" To overcome an NVRAM lock caused by a missing or inaccessible ubuntu-x64.efi file, you must manually create a fallback bootloader in the EFI System Partition (ESP) since efibootmgr cannot register new entries. The most effective solution involves using GRUB's bootx64.efi fallback or the UEFI shell to chainload the existing Ubuntu kernel, bypassing the need to write directly to the locked NVRAM.

Manual Fallback Bootloader Creation

When NVRAM is locked, the system ignores standard boot entries, so you must place a bootloader at the default UEFI fallback path (\EFI\BOOT\BOOTX64.EFI ). This forces the firmware to boot Ubuntu if no other valid NVRAM entry is found.

  • Boot into a Live USB environment that matches your installed system's architecture (x86_64).
  • Mount your EFI System Partition (ESP) and ensure the grubx64.efi file exists in /boot/efi/EFI/ubuntu/ .
  • Copy the Ubuntu bootloader to the fallback location using the command:
sudo cp /boot/efi/EFI/ubuntu/grubx64.efi /boot/efi/EFI/BOOT/BOOTX64.EFI
  • Create a custom grub.cfg in /boot/efi/EFI/BOOT/ to chainload the Ubuntu kernel if the firmware fails to locate the entry automatically.

Alternative: UEFI Shell and BootICE

If copying the fallback file does not resolve the issue, you can use external tools to manually edit the boot path or utilize the UEFI shell directly.

  • Use BootICE : On a Windows host, run the BootICE tool to edit the topmost "Windows Boot Manager" entry and change the path to point to EFI\ubuntu\shimx64.efi (if Secure Boot is enabled) or EFI\ubuntu\grubx64.efi (if disabled).
  • UEFI Shell : If your system supports it, boot into the UEFI Shell and manually execute shimx64.efi or grubx64.efi from the ESP to load the OS.
  • BIOS/UEFI Settings : Verify that Secure Boot is disabled if you are using unsigned bootloaders, as this can prevent the system from reading the EFI files even if they are present.

Troubleshooting and Verification

If the system still fails to boot, ensure the efivars module is loaded and the NVRAM lock is not caused by a corrupted firmware state.

  • Reset NVRAM : Some manufacturers (e.g., Dell) require a hard reset (holding the power button for 20 seconds after power removal) to clear the RTC and potentially unlock NVRAM.
  • Boot-Repair : Use the Boot-Repair utility in "Advanced Options" to manually specify the GRUB location and purge/reinstall GRUB, though this may still fail if the NVRAM lock persists.
  • Legacy Boot : As a last resort, consider switching the system to Legacy/CSM mode and installing Ubuntu with a bios_grub partition, bypassing UEFI entirely.

AI-generated answer. Please verify critical facts."

Additionally I did not use GPT when setting up Q4OS alongside Windows 11 on youngest's machine.