[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 [2013/12/27 01:58 (UTC)] – Updated info and added ESP section metaschima | howtos:slackware_admin:linux_kernel_options_for_uefi_and_elilo [2021/01/11 06:41 (UTC)] – fix to correctly set partition and device even on mmcblk louigi600 | ||
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* EFI Variable Support via sysfs (CONFIG_EFI_VARS [=n]) | * EFI Variable Support via sysfs (CONFIG_EFI_VARS [=n]) | ||
as it is deprecated in favor of CONFIG_EFIVAR_FS, | as it is deprecated in favor of CONFIG_EFIVAR_FS, | ||
- | However, if you do disable this, you will need a fork of the '' | + | However, if you do disable this, you will need a fork of the '' |
- | https:// | + | |
</ | </ | ||
+ | ==== Using the new EFI variable filesystem ==== | ||
+ | In order to use the new EFI variable filesystem interface, you need to remove the old '' | ||
+ | - Download and install: https:// | ||
+ | - Download and install: https:// | ||
+ | - Run:< | ||
+ | modprobe efivarfs | ||
+ | mount -t efivarfs efivarfs / | ||
+ | efibootmgr | ||
+ | </ | ||
==== The EFI System Partition (ESP) ==== | ==== The EFI System Partition (ESP) ==== | ||
In order to boot from UEFI you need to create an EFI System Partition (ESP) using '' | In order to boot from UEFI you need to create an EFI System Partition (ESP) using '' | ||
==== UEFI and ELILO ==== | ==== UEFI and ELILO ==== | ||
- | During the install procedure of Slackware 14.1 for ELILO (the '' | + | During the install procedure of Slackware 14.1 or above for ELILO (the '' |
- The EFI System Partition (ESP) is located and mounted. On a running system it is usually found already mounted at ''/ | - The EFI System Partition (ESP) is located and mounted. On a running system it is usually found already mounted at ''/ | ||
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- The kernel, usually titled '' | - The kernel, usually titled '' | ||
- A boot entry variable is registered in the UEFI firmware using '' | - A boot entry variable is registered in the UEFI firmware using '' | ||
- | EFI_DEVICE=$(mount | grep vfat | grep -w /boot/efi | cut -b 1-8) | + | EFIDISK=$(df |
- | EFI_PARTITION=$(mount | grep vfat | grep -w /boot/efi | cut -f 1 -d ' ' | + | EFI_DEVICE=$(sed 's%[0-9]$%%; |
+ | EFI_PARTITION=$(sed | ||
efibootmgr -q -c -d $EFI_DEVICE -p $EFI_PARTITION -l " | efibootmgr -q -c -d $EFI_DEVICE -p $EFI_PARTITION -l " | ||
</ | </ | ||
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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. | ||
+ | </ | ||
+ | ==== 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: | ||
+ | - '' | ||
+ | - '' | ||
+ | - '' | ||
+ | - 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 ''/'' | ||
+ | - [[https:// | ||
+ | - [[http:// | ||
+ | - Boot into the shell and run: < | ||
+ | ==== External Links ==== | ||
+ | [[http:// | ||
====== Sources ====== | ====== Sources ====== | ||
* Original author: [[wiki: | * Original author: [[wiki: |