[2024-feb-29] Sad news: Eric Layton aka Nocturnal Slacker aka vtel57 passed away on Feb 26th, shortly after hospitalization. He was one of our Wiki's most prominent admins. He will be missed.

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howtos:slackware_admin:linux_kernel_options_for_uefi_and_elilo [2014/07/06 01:30 (UTC)] – [Using the new EFI variable filesystem] metaschimahowtos:slackware_admin:linux_kernel_options_for_uefi_and_elilo [2015/02/14 15:50 (UTC)] – [My UEFI settings were reset and I can't boot, or planning ahead to avoid surprises] Fix Typo - EPS -> ESP turtleli
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 ==== Updating your UEFI firmware ==== ==== Updating your UEFI firmware ====
 As all UEFI firmware has a flashing utility built-in, it is now much easier to update the firmware. All you have to do is copy the new firmware onto the ESP and the UEFI firmware should recognize it when you go to the flashing utility menu. However, remember that flashing the firmware can still potentially brick the system, especially if it is interrupted during the flashing process. As all UEFI firmware has a flashing utility built-in, it is now much easier to update the firmware. All you have to do is copy the new firmware onto the ESP and the UEFI firmware should recognize it when you go to the flashing utility menu. However, remember that flashing the firmware can still potentially brick the system, especially if it is interrupted during the flashing process.
 +<note important>
 +Updating your UEFI firmware may reset your settings and prevent you from booting unless you plan ahead.
 +</note>
 +==== My UEFI settings were reset and I can't boot, or planning ahead to avoid surprises ====
 +This can happen either after updating the UEFI firmware or after replacing the CMOS battery. There are three main ways to fix it:
 +  - Probably the easiest and most convenient way is to use the default boot location. Note that some UEFI firmwares do NOT support the default boot location, so this will not work. However, if it does, you won't have to worry about the system not booting again. To do this you can boot into the Slackware install DVD, mount the ESP and copy the files to the following places:
 +    - ''elilo.efi'' -> ''/EFI/boot/bootx64.efi''
 +    - ''elilo.conf'' -> ''/EFI/boot/elilo.conf''
 +    - ''vmlinuz'' -> ''/EFI/boot/vmlinuz''
 +  - You can boot into the Slackware install DVD, run through the menus, and reinstall elilo.
 +  - You can download and install one of the following EFI shells to the root directory of your ESP (that is ''/'' NOT ''/EFI'').
 +    - [[https://svn.code.sf.net/p/edk2/code/trunk/edk2/ShellBinPkg/UefiShell/X64/Shell.efi|This version supports only UEFI version 2 and up]]
 +    - [[http://dl.dropbox.com/u/17629062/Shell2.zip | This version may support earlier UEFI versions]]
 +    - Boot into the shell and run: <code>bcfg boot add 0 fs0:\EFI\Slackware\elilo.efi Slackware</code>
 ==== External Links ==== ==== External Links ====
 [[http://blog.uncooperative.org/blog/2014/02/06/the-efi-system-partition/|A comprehensive analysis of the ESP and default boot behavior.]] [[http://blog.uncooperative.org/blog/2014/02/06/the-efi-system-partition/|A comprehensive analysis of the ESP and default boot behavior.]]

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