From 714fb2a9919e1664ba9370ea98fb7277f0feacfa Mon Sep 17 00:00:00 2001 From: Lukas Ruzicka Date: Thu, 14 Dec 2017 14:10:49 +0530 Subject: [PATCH] Delete grub2.adoc --- en-US/grub2.adoc | 482 ----------------------------------------------- 1 file changed, 482 deletions(-) delete mode 100644 en-US/grub2.adoc diff --git a/en-US/grub2.adoc b/en-US/grub2.adoc deleted file mode 100644 index 8fab5a2..0000000 --- a/en-US/grub2.adoc +++ /dev/null @@ -1,482 +0,0 @@ -= GRUB 2 - -''' - -[IMPORTANT] -====== - -This page was automatically converted from https://fedoraproject.org/wiki/GRUB_2 - -It is probably - -* Badly formatted -* Missing graphics and tables that do not convert well from mediawiki -* Out-of-date -* In need of other love - -Please fix it, remove this notice, and then add to `_topic_map.yml` - -Pull requests accepted at https://pagure.io/fedora-docs/quick-docs - -Once that is live, go to the original wiki page and add an `{{old}}` -tag, followed by a note like - -.... -{{admon/note|This page has a new home!| -This wiki page is no longer maintained. Please find the up-to-date -version at: https://docs.fedoraproject.org/whatever-the-url -}} -.... - -====== - -''' - - -[[introduction]] -Introduction ------------- - -GRUB 2 is the latest version of GNU GRUB, the GRand Unified Bootloader. -A bootloader is the first software program that runs when a computer -starts. It is responsible for loading and transferring control to the -operating system kernel, (Linux, in the case of Fedora). The kernel, in -turn, initializes the rest of the operating system. - -GRUB 2 has replaced what was formerly known as GRUB (i.e. version 0.9x), -which has, in turn, become GRUB Legacy. - -Starting with Fedora 16, GRUB 2 is the default bootloader on x86 BIOS -systems. For upgrades of BIOS systems the default is also to install -GRUB 2, but you can opt to skip bootloader configuration entirely. - -[[tasks-common-issues]] -Tasks / Common issues ---------------------- - -[[updating-grub-2-configuration-on-bios-systems]] -Updating GRUB 2 configuration on BIOS systems -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ - -The grub2 packages contain commands for installing a bootloader and for -creating a bootloader configuration file. - -grub2-install will install the bootloader - usually in the MBR, in free -unpartioned space, and as files in /boot. The bootloader is installed -with something like: - -.... -grub2-install /dev/sda -.... - -grub2-mkconfig will create a new configuration based on the currently -running system, what is found in /boot, what is set in -/etc/default/grub, and the customizable scripts in /etc/grub.d/ . A new -configuration file is created with: - -.... -grub2-mkconfig -o /boot/grub2/grub.cfg -.... - -The configuration format has evolved over time, and a new configuration -file might be slightly incompatible with the old bootloader. It is -therefore a good idea to first run grub2-install whenever you would need -to run grub2-mkconfig. - -The Fedora installer, anaconda, will run these grub2 commands and there -is usually no reason to run them manually. - -It is generally safe to directly edit /boot/grub2/grub.cfg in Fedora. -Grubby in Fedora patches the configuration when a kernel update is -performed and will try to not make any other changes than what is -necessary. (Other distributions, in particular Debian and Debian-derived -distributions provide a software patch that adds an command which is -neither included nor needed in Fedora.) Manual changes might however be -overwritten with grub2-mkconfig next time the system is upgraded with -anaconda. Some customizations can be placed in /etc/grub.d/40_custom or -/boot/grub2/custom.cfg and will survive running grub2-mkconfig. - -[[updating-grub-2-configuration-on-uefi-systems]] -Updating GRUB 2 configuration on UEFI systems -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ - -To install or fix GRUB 2 on a UEFI system on Fedora 18 or newer, you -need to do four things: - -[[create-an-esp]] -Create an ESP -^^^^^^^^^^^^^ - -UEFI firmware, in general, likes to boot from an EFI System Partition on -a disk with a GPT label. In `gdisk`, it looks something like this: - -.... -Number Start (sector) End (sector) Size Code Name - 1 2048 264191 128.0 MiB EF00 EFI System -.... - -That partition should be formatted as FAT. If in doubt, FAT32 is a good -dialect of FAT to choose. - -Fedora expects this partition to be mounted at `/boot/efi`. - -[[install-the-bootloader-files]] -Install the bootloader files -^^^^^^^^^^^^^^^^^^^^^^^^^^^^ - -If you don't already have the relevant packages installed, do for Fedora -22 and later versions with link:dnf[DNF] or with YUM for older Fedora -releases: - -.... -dnf install grub2-efi grub2-efi-modules shim -yum install grub2-efi grub2-efi-modules shim -.... - -If you do, then try: - -.... -dnf reinstall grub2-efi grub2-efi-modules shim -yum reinstall grub2-efi grub2-efi-modules shim -.... - -instead. - -Make sure that /boot/efi is mounted when you do this. - -This installs the signed shim and the GRUB 2 binary. - -[[create-a-grub-2-configuration]] -Create a GRUB 2 configuration -^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ - -Under EFI, GRUB 2 looks for its configuration in -`/boot/efi/EFI/fedora/grub.cfg`. For newly installed kernels to work, -`grubby` expects `/etc/grub2-efi.cfg` to be a symlink to the real -grub.cfg (i.e. `/boot/efi/EFI/fedora/grub.cfg`). - -If you already have a grub 2 EFI config file, you should be okay. If -not, grub2-mkconfig can help, but your mileage may vary. - -`   grub2-mkconfig -o /boot/efi/EFI/fedora/grub.cfg` - -[[create-a-boot-menu-entry]] -Create a boot menu entry -^^^^^^^^^^^^^^^^^^^^^^^^ - -TL;DR: This should happen automatically. If it doesn't, read on. - -When you power on your system, your firmware will look for EFI variables -that tell it how to boot. If you're already booted in EFI mode and EFI -runtime services are working correctly, you can configure your boot menu -with `efibootmgr`. If not, you'll have to bootstrap the process. - -Fortunately, `shim` can help you bootstrap. The EFI program -`/boot/efi/EFI/BOOT/fallback.efi` will look for files called `BOOT.CSV` -in your ESP and will add boot entries corresponding to them, *if such -entries do not already appear to exist*. `shim` provides a `BOOT.CSV` -file that will add an entry for `grub2-efi` for you. So just using the -EFI Shell to invoke `fallback.efi` should do the trick. You can do this -with commands like: - -.... -> fs0: -> cd EFI\BOOT -> fallback.efi -.... - -If you have no boot entries at all, then just booting off your disk in -UEFI mode should automatically invoke `/boot/efi/EFI/BOOT/BOOTX64.EFI`, -which will, in turn, invoke `fallback.efi`. - -If you already have incorrect boot entries, you'll either need to delete -them or to modify `BOOT.CSV` to create new entries with different names. - -[[adding-other-operating-systems-to-the-grub-2-menu]] -Adding Other operating systems to the GRUB 2 menu -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ - -grub2-mkconfig will add entries for other operating systems it can find. -That will be done based on the output of the os-prober tool. - -That might however not work so well, especially not for booting other -Linux operating systems, and especially not on UEFI systems. See -http://www.gnu.org/software/grub/manual/grub.html#Multi_002dboot-manual-config -. - -[[setting-default-entry]] -Setting default entry -~~~~~~~~~~~~~~~~~~~~~ - -Due to `grub2-mkconfig` (and os-prober) we cannot predict the order of -the entries in `/boot/grub2/grub.cfg`, so we set the default by -name/title instead. - -Open `/etc/default/grub` and ensure this line exists: - -.... -GRUB_DEFAULT=saved -.... - -and ensure this line not exists: - -.... -GRUB_SAVEDEFAULT=true -.... - -or ensure this line exists: - -.... -GRUB_SAVEDEFAULT=false -.... - -Apply the change to `grub.cfg` by running: - -.... -grub2-mkconfig -o /boot/grub2/grub.cfg -.... - -Now list all possible menu entries - -.... -grep -P "submenu|^menuentry" /boot/grub2/grub.cfg | cut -d "'" -f2 -.... - -Now set the desired default menu entry - -.... -grub2-set-default "" -.... - -Verify the default menu entry - -.... -grub2-editenv list -.... - -If you understand the risks involved and still want to directly modify -/boot/grub2/grub.cfg, here's how you can do it: - -Edit /boot/grub2/grub.cfg, and change the line - -.... -set default="0" -.... - -to - -.... -set default="5" -.... - -[[encountering-the-dreaded-grub-2-boot-prompt]] -Encountering the dreaded GRUB 2 boot prompt -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ - -If improperly configured, GRUB 2 may fail to load and subsequently drop -to a boot prompt. To address this issue, proceed as follows: - -\0. Load the XFS and LVM modules - -.... -insmod xfs -insmod lvm -.... - -\1. List the drives which GRUB 2 sees: - -.... -grub2> ls -.... - -\2. The output for a dos partition table /dev/sda with three partitons -will look something like this: - -.... -(hd0) (hd0,msdos3) (hd0,msdos2) (hd0,msdos1) -.... - -\3. While the output for a gpt partition table /dev/sda with four -partitions will look something like this: - -.... -(hd0) (hd0,gpt4) (hd0,gpt3) (hd0,gpt2) (hd0,gpt1) -.... - -\4. With this information you can now probe each partition of the drive -and locate your vmlinuz and initramfs files: - -.... -ls (hd0,1)/ -.... - -Will list the files on /dev/sda1. If this partition contains /boot, the -output will show the full name of vmlinuz and initramfs. - -\5. Armed with the location and full name of vmlinuz and initramfs you -can now boot your system. - -5a. Declare your root partition: - -.... -grub> set root=(hd0,3) -.... - -5b. Declare the kernel you wish to use: - -.... -grub> linux (hd0,1)/vmlinuz-3.0.0-1.fc16.i686 root=/dev/sda3 rhgb quiet selinux=0 -# NOTE : add other kernel args if you have need of them -# NOTE : change the numbers to match your system -.... - -5c. Declare the initrd to use: - -.... - -grub> initrd (hd0,1)/initramfs-3.0.0-1.fc16.i686.img -# NOTE : change the numbers to match your system -.... - -5d. Instruct GRUB 2 to boot the chosen files: - -.... -grub> boot -.... - -\6. After boot, open a terminal. - -\7. Issue the grub2-mkconfig command to re-create the grub.cfg file -grub2 needed to boot your system: - -.... -grub2-mkconfig -o /boot/grub2/grub.cfg -.... - -\8. Issue the grub2-install command to install grub2 to your hard drive -and make use of your config: - -.... -grub2-install --boot-directory=/boot /dev/sda -# Note: your drive may have another device name. Check for it with mount command output. -.... - -[[additional-scenario]] -Additional Scenario -~~~~~~~~~~~~~~~~~~~ - -It's also possible to boot into a _configfile_ that's located on another -partition. If the user is faced with such a scenario, as is often the -case with multi-boot systems containing Ubuntu and Fedora, the following -steps in the grub rescue shell might become useful to know: - -.... -insmod part_msdos -insmod xfs -insmod lvm -set root='hd0,msdos1' -configfile /grub2/grub.cfg -.... - -Where, *hd0,msdos1* is the pertinent _boot_ partition, which holds the -grub.cfg file. - -[[other-grub-2-issues]] -Other GRUB 2 issues -~~~~~~~~~~~~~~~~~~~ - -''' Absent Floppy Disk ''': It has been reported by some users that GRUB -2 may fail to install on a partition's boot sector if the computer -floppy controller is activated in BIOS without an actual floppy disk -drive being present. A possible workaround is to run (post OS install) -from rescue mode: - -.... -grub2-install --no-floppy -.... - -[[setting-a-password-for-interactive-edit-mode]] -Setting a password for interactive edit mode -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ - -If you wish to password-protect GRUB2's interactive edit mode *but* you -do not want to require users to enter a password to do a plain, simple, -ordinary boot, create /etc/grub.d/01_users with the following lines: - -.... -cat << EOF -set superusers="root" -export superusers -password root secret -EOF -.... - -To apply your changes run: - -.... -grub2-mkconfig -o /boot/grub2/grub.cfg -.... - -You can encrypt the password by using pbkdf2. Use grub2-mkpasswd-pbkdf2 -to encrypt the password, then replace the password line with: - -.... -password_pbkdf2 root grub.pbkdf2.sha512.10000.1B4BD9B60DE889A4C50AA9458C4044CBE129C9607B6231783F7E4E7191D8254C0732F4255178E2677BBE27D03186E44815EEFBAD82737D81C87F5D24313DDDE7.E9AEB53A46A16F30735E2558100D8340049A719474AEEE7E3F44C9C5201E2CA82221DCF2A12C39112A701292BF4AA071EB13E5EC8C8C84CC4B1A83304EA10F74 -.... - -More details can be found at -https://help.ubuntu.com/community/Grub2/Passwords[Ubuntu Help: GRUB2 -Passwords]. - -Starting from atleast Fedora 21, the `--md5pass` kickstart option must -be set using output from grub2-mkpasswd-pbkdf2. - -[[using-old-graphics-modes-in-bootloader]] -Using old graphics modes in bootloader -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ - -Terminal device is chosen with GRUB_TERMINAL; additional quote from -http://www.gnu.org/software/grub/manual/grub.html#Simple-configuration - - Valid terminal output names depend on the platform, but may include -‘console’ (PC BIOS and EFI consoles), ‘serial’ (serial terminal), -‘gfxterm’ (graphics-mode output), ‘ofconsole’ (Open Firmware console), -or ‘vga_text’ (VGA text output, mainly useful with Coreboot). - -The default is to use the platform's native terminal output. - -The default in Fedora is gfxterm and to get the legacy graphics modes -you need to set GRUB_TERMINAL to right variable from the description -above in /etc/default/grub - -[[enable-serial-console-in-grub]] -Enable Serial Console in Grub -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ - -To enable Serial console in grub add the following entry's to -/etc/default/grub - -( Adjust baudrate/parity/bits/flow control to fit your environment and -cables) - -.... -GRUB_CMDLINE_LINUX='console=tty0 console=ttyS0,115200n8' -GRUB_TERMINAL=serial -GRUB_SERIAL_COMMAND="serial --speed=115200 --unit=0 --word=8 --parity=no --stop=1" -.... - -And re-generate grub - -`grub2-mkconfig -o /boot/grub2/grub.cfg` - -[[further-reading]] -Further Reading ---------------- - -* http://www.gnu.org/software/grub/manual/grub.html -* Features/Grub2 -* Anaconda/Features/Grub2Migration -''' - -See a typo, something missing or out of date, or anything else which can be -improved? Edit this document at https://pagure.io/fedora-docs/quick-docs.