Konfiguracja programu rozruchowego
Wybór programu rozruchowego
Z skonfigurowanym jadrem Linuksa, zainstalowanymi narzędziami systemowymi i z zmodyfikowanymi plikami konfiguracyjnymi, przyszedł czas na instalację ostatniej ważnej części systemu Linux: systemu rozruchowego.
System rozruchowy jest odpowiedzialny za uruchomienie jądra systemu Linux podczas startu komputera - bez niego, komputer nie wiedziałby co należy zrobić po wciśnięciu przycisku zasilania.
Dla amd64, udokumentowaliśmy jak skonfigurować zarówno GRUB2 jak i LILO dla systemów opartych o BIOS, oraz GRUB2 i efibootmgr dla systemów UEFI.
W tej sekcji Podręcznika dokonano podziału pomiędzy "emerge" systemu rozruchowego, a "instalacją" systemu rozruchowego na dysk systemowy. Pojęcie "emerge" będzie używane do zapytania Portage o utworzenie pakietu oprogramowania dostępnego dla systemu. Pojęcie "instalacja" będzie oznaczało kopiowanie plików systemu rozruchowego lub fizyczną modyfikację stosownych sekcji dysku systemowego, w celu "uaktywnienia i przygotowania do działania" systemu rozruchowego na następne uruchomienie systemu operacyjnego.
Domyślnie: GRUB2
Domyślnie, większość systemów Gentoo korzysta teraz z GRUB2 (znajdującego się w pakiecie sys-boot/grub), który jest sukcesorem przestarzałego GRUB. Bez dodatkowej konfiguracji, GRUB2 wspiera starsze wersje BIOS. Z drobną konfiguracją, niezbędną przed kompilacją pakietu, GRUB2 może wspierać więcej niż tuzin dodatkowych platform sprzętowych. Więcej informacji znajdziesz w sekcji Wymagania wstępne artykułu GRUB2.
Emerge
Podczas korzystania z starszego BIOS, system wspiera jedynie tablicę partycji MBR. Nie ma potrzeby dodatkowej konfiguracji w celu zainstalowania systemu rozruchowego GRUB:
root #
emerge --ask --verbose sys-boot/grub:2
Informacja dla użytkowników UEFI: uruchomienie powyższej komendy wyświetli aktualną zawartość GRUB_PLATFORMS przed przystąpieniem do kompilacji. Użytkownicy systemów UEFI muszą zapewnić włączenie opcji GRUB_PLATFORMS="efi-64"
(jak ma to miejsce domyślnie). Jeżeli opcja nie jest włączona, GRUB_PLATFORMS="efi-64"
musi zostać dodane do pliku /etc/portage/make.conf przed przystąpieniem do kompilacji GRUB2, tak aby pakiet był skompilowany z funkcjonalnością EFI:
root #
echo 'GRUB_PLATFORMS="efi-64"' >> /etc/portage/make.conf
root #
emerge --ask sys-boot/grub:2
- Jeżeli GRUB2 został jakkolwiek skompilowany bez włączenia
GRUB_PLATFORMS="efi-64"
, linia ta (jak wyżej wskazano) nadal może zostać dodana do pliku make.conf, a zależności zbioru pakietów world ponownie obliczone poprzez użycie opcji--update --newuse
dla polecenia emerge:
root #
emerge --ask --update --newuse --verbose sys-boot/grub:2
Oprogramowanie GRUB2 zostało właśnie przyłączone do systemu, ale nie zostało jeszcze zainstalowane.
Instalacja
Następnie, zainstaluj niezbędne pliki GRUB2 do ścieżki /boot/grub/ poprzez komendę grub-install. Zakładając, że pierwszy dysk (ten z którego system się uruchamia) to /dev/sda, uruchom jedno z poniższych poleceń:
- Podczas korzystania z BIOS:
root #
grub-install /dev/sda
For DOS/Legacy BIOS systems:
root #
grub-install /dev/sda
Podczas korzystania z UEFI:
- Ważne
Upewnij się, że partycja systemowa EFI została zamontowana przed uruchomieniem grub-install. Istnieje ryzyko, że grub-install zainstaluje plik GRUB EFI (grubx64.efi) w złej ścieżce bez podania jakiegokolwiek wskazania, że użyto złej ścieżki
For UEFI systems:
root #
grub-install --target=x86_64-efi --efi-directory=/boot
Upon successful installation, the output should match the output of the previous command. If the output does not match exactly, then proceed to Debugging GRUB, otherwise jump to the Configure step.
Optional: Secure Boot
To successfully boot with secure boot enabled the signing certificate must either be accepted by the UEFI firmware, or shim must be used as a pre-loader. Shim is pre-signed with the third-party Microsoft Certificate, accepted by default by most UEFI motherboards.
How to configure the UEFI firmware to accept custom keys depends on the firmware vendor, which is beyond the scope of the handbook. Below is shown how to setup shim instead. Here it is assumed that the user has already followed the instructions in the previous sections to generate a signing key and to configure portage to use it. If this is not the case please return first to the Kernel installation section.
The package sys-boot/grub installs a prebuilt and signed stand-alone EFI executable if the secureboot USE flag is enabled. Install the required packages and copy the stand-alone grub, Shim, and the MokManager to the same directory on the EFI System Partition. For example:
root #
emerge sys-boot/grub sys-boot/shim sys-boot/mokutil sys-boot/efibootmgr
root #
cp /usr/share/shim/BOOTX64.EFI /efi/EFI/Gentoo/shimx64.efi
root #
cp /usr/share/shim/mmx64.efi /efi/EFI/Gentoo/mmx64.efi
root #
cp /usr/lib/grub/grub-x86_64.efi.signed /efi/EFI/Gentoo/grubx64.efi
Next register the signing key in shims MOKlist, this requires keys in the DER format, whereas sbsign and the kernel build system expect keys in the PEM format. In the previous sections of the handbook an example was shown to generate such a signing PEM key, this key must now be converted to the DER format:
root #
openssl x509 -in /path/to/kernel_key.pem -inform PEM -out /path/to/kernel_key.der -outform DER
The path used here must be the path to the pem file containing the certificate belonging to the generated key. In this example both key and certificate are in the same pem file.
Then the converted certificate can be imported into Shims MOKlist, this command will ask to set some password for the import request:
root #
mokutil --import /path/to/kernel_key.der
When the currently booted kernel already trusts the certificate being imported, the message "Already in kernel trusted keyring." will be returned here. If this happens, re-run the above command with the argument --ignore-keyring added.
Next, register Shim with the UEFI firmware. In the following command, boot-disk
and boot-partition-id
must be replaced with the disk and partition identifier of the EFI system partition:
root #
efibootmgr --create --disk /dev/boot-disk --part boot-partition-id --loader '\EFI\Gentoo\shimx64.efi' --label 'GRUB via Shim' --unicode
Note that this prebuilt and signed stand-alone version of grub reads the grub.cfg from a different location then usual. Instead of the default /boot/grub/grub.cfg the config file should be in the same directory that the grub EFI executable is in, e.g. /efi/EFI/Gentoo/grub.cfg. When sys-kernel/installkernel is used to install the kernel and update the grub configuration then the GRUB_CFG environment variable may be used to override the usual location of the grub config file.
For example:
root #
grub-mkconfig -o /efi/EFI/Gentoo/grub.cfg
Or, via installkernel:
/etc/env.d/99grub
GRUB_CFG=/efi/EFI/Gentoo/grub.cfg
root #
env-update
The import process will not be completed until the system is rebooted. After completing all steps in the handbook, restart the system and Shim will load, it will find the import request registered by mokutil. The MokManager application will start and ask for the password that was set when creating the import request. Follow the on-screen instructions to complete the import of the certificate, then reboot the system into the UEFI menu and enable the Secure Boot setting.
Debugging GRUB
When debugging GRUB, there are a couple of quick fixes that may result in a bootable installation without having to reboot to a new live image environment.
In the event that "EFI variables are not supported on this system" is displayed somewhere in the output, it is likely the live image was not booted in EFI mode and is presently in Legacy BIOS boot mode. The solution is to try the removable GRUB step mentioned below. This will overwrite the executable EFI file located at /EFI/BOOT/BOOTX64.EFI. Upon rebooting in EFI mode, the motherboard firmware may execute this default boot entry and execute GRUB.
- Ważne
Jeśli grub-install zwraca błąd podobny doCould not prepare Boot variable: Read-only file system
, może być konieczne ponowne zamontowanie efivars w trybie do odczytu i zapisu, aby odnieść sukces:root #
mount -o remount,rw /sys/firmware/efi/efivars
root #
mount -o remount,rw,nosuid,nodev,noexec --types efivarfs efivarfs /sys/firmware/efi/efivars
This is caused by certain non-official Gentoo environments not mounting the special EFI filesystem by default. If the previous command does not run, then reboot using an official Gentoo live image environment in EFI mode.
Some motherboard manufacturers with poor UEFI implementations seem to only support the /EFI/BOOT directory location for the .EFI file in the EFI System Partition (ESP). The GRUB installer can create the .EFI file in this location automatically by appending the --removable
option to the install command. Ensure the ESP has been mounted before running the following command; presuming it is mounted at /efi (as defined earlier), run:
root #
grub-install --target=x86_64-efi --efi-directory=/boot --removable
This creates the 'default' directory defined by the UEFI specification, and then creates a file with the default name: BOOTX64.EFI.
Konfiguracja
Next, generate the GRUB configuration based on the user configuration specified in the /etc/default/grub file and /etc/grub.d scripts. In most cases, no configuration is needed by users as GRUB will automatically detect which kernel to boot (the highest one available in /boot/) and what the root file system is. It is also possible to append kernel parameters in /etc/default/grub using the GRUB_CMDLINE_LINUX variable.
Aby wygenerować końcową konfigurację GRUB2, uruchom polecenie grub-mkconfig:
root #
grub-mkconfig -o /boot/grub/grub.cfg
Generating grub.cfg ... Found linux image: /boot/vmlinuz-6.6.21-gentoo Found initrd image: /boot/initramfs-genkernel-amd64-6.6.21-gentoo done
The output of the command must mention that at least one Linux image is found, as those are needed to boot the system. If an initramfs is used or genkernel was used to build the kernel, the correct initrd image should be detected as well. If this is not the case, go to /boot/ and check the contents using the ls command. If the files are indeed missing, go back to the kernel configuration and installation instructions.
The os-prober utility can be used in conjunction with GRUB to detect other operating systems from attached drives. Windows 7, 8.1, 10, and other distributions of Linux are detectable. Those desiring dual boot systems should emerge the sys-boot/os-prober package then re-run the grub-mkconfig command (as seen above). If detection problems are encountered be sure to read the GRUB article in its entirety before asking the Gentoo community for support.
Alternative 1: systemd-boot
Another option is systemd-boot, which works on both OpenRC and systemd machines. It is a thin chainloader and works well with secure boot.
Emerge
To install systemd-boot, enable the boot USE flag and re-install sys-apps/systemd (for systemd systems) or sys-apps/systemd-utils (for OpenRC systems):
/etc/portage/package.use/systemd-boot
sys-apps/systemd boot
sys-apps/systemd-utils boot
root #
emerge --ask sys-apps/systemd
Or
root #
emerge --ask sys-apps/systemd-utils
Installation
Now, install the systemd-boot loader to the EFI System Partition:
root #
bootctl install
Make sure the EFI system partition has been mounted before running bootctl install.
When using this bootloader, before rebooting, verify that a new bootable entry exists using:
root #
bootctl list
The kernel command line for new systemd-boot entries is read from /etc/kernel/cmdline or /usr/lib/kernel/cmdline. If neither file is present, then the kernel command line of the currently booted kernel is re-used (/proc/cmdline). On new installs it might therefore happen that the kernel command line of the live CD is accidentally used to boot the new kernel. The kernel command line for registered entries can be checked with:
root #
bootctl list
If no new entry exists, ensure the sys-kernel/installkernel package has been installed with the systemd and systemd-boot USE flags enabled, and re-run the kernel installation.
For the distribution kernels:
root #
emerge --ask --config sys-kernel/gentoo-kernel
For a manually configured and compiled kernel:
root #
make install
When installing kernels for systemd-boot, no root= kernel command line argument is added by default. On systemd systems that are using an initramfs users may rely instead on systemd-gpt-auto-generator to automatically find the root partition at boot. Otherwise users should manually specify the location of the root partition by setting root= in /etc/kernel/cmdline as well as any other kernel command line arguments that should be used. And then reinstalling the kernel as described above.
Optional: Secure Boot
When the secureboot USE flag is enabled, the systemd-boot EFI executable will be signed by portage automatically. Furthermore, bootctl install will automatically install the signed version.
To successfully boot with secure boot enabled the used certificate must either be accepted by the UEFI firmware, or shim must be used as a pre-loader. Shim is pre-signed with the third-party Microsoft Certificate, accepted by default by most UEFI motherboards.
How to configure the UEFI firmware to accept custom keys depends on the firmware vendor, which is beyond the scope of the handbook. Below is shown how to setup shim instead. Here it is assumed that the user has already followed the instructions in the previous sections to generate a signing key and to configure portage to use it. If this is not the case please return first to the Kernel installation section.
root #
emerge --ask sys-boot/shim sys-boot/mokutil sys-boot/efibootmgr
root #
bootctl install --no-variables
root #
cp /usr/share/shim/BOOTX64.EFI /efi/EFI/systemd/shimx64.efi
root #
cp /usr/share/shim/mmx64.efi /efi/EFI/systemd/mmx64.efi
Shims MOKlist requires keys in the DER format, whereas sbsign and the kernel build system expect keys in the PEM format. In the previous sections of the handbook an example was shown to generate such a signing PEM key, this key must now be converted to the DER format:
root #
openssl x509 -in /path/to/kernel_key.pem -inform PEM -out /path/to/kernel_key.der -outform DER
The path used here must be the path to the pem file containing the certificate belonging to the generated key. In this example both key and certificate are in the same pem file.
Then the converted certificate can be imported into Shims MOKlist:
root #
mokutil --import /path/to/kernel_key.der
When the currently booted kernel already trusts the certificate being imported, the message "Already in kernel trusted keyring." will be returned here. If this happens, re-run the above command with the argument --ignore-keyring added.
And finally we register Shim with the UEFI firmware. In the following command, boot-disk
and boot-partition-id
must be replaced with the disk and partition identifier of the EFI system partition:
root #
efibootmgr --create --disk /dev/boot-disk --part boot-partition-id --loader '\EFI\systemd\shimx64.efi' --label 'Systemd-boot via Shim' --unicode '\EFI\systemd\systemd-bootx64.efi'
The import process will not be completed until the system is rebooted. After completing all steps in the handbook, restart the system and Shim will load, it will find the import request registered by mokutil. The MokManager application will start and ask for the password that was set when creating the import request. Follow the on-screen instructions to complete the import of the certificate, then reboot the system into the UEFI menu and enable the Secure Boot setting.
Alternative 2: EFI Stub
Computer systems with UEFI-based firmware technically do not need secondary bootloaders (e.g. GRUB) in order to boot kernels. Secondary bootloaders exist to extend the functionality of UEFI firmware during the boot process. Using GRUB (see the prior section) is typically easier and more robust because it offers a more flexible approach for quickly modifying kernel parameters at boot time.
System administrators who desire to take a minimalist, although more rigid, approach to booting the system can avoid secondary bootloaders and boot the Linux kernel as an EFI stub.
The sys-boot/efibootmgr application is a tool to used interact with UEFI firmware - the system's primary bootloader. Normally this looks like adding or removing boot entries to the firmware's list of bootable entries. It can also update firmware settings so that the Linux kernels that were previously added as bootable entries can be executed with additional options. These interactions are performed through special data structures called EFI variables (hence the need for kernel support of EFI vars).
Ensure the EFI stub kernel article has been reviewed before continuing. The kernel must have specific options enabled to be directly bootable by the UEFI firmware. It may be necessary to recompile the kernel in order to build-in this support.
It is also a good idea to take a look at the efibootmgr article for additional information.
To reiterate, efibootmgr is not a requirement to boot an UEFI system; it is merely necessary to add an entry for an EFI-stub kernel into the UEFI firmware. When built appropriately with EFI stub support, the Linux kernel itself can be booted directly. Additional kernel command-line options can be built-in to the Linux kernel (there is a kernel configuration option called CONFIG_CMDLINE. Similarly, support for initramfs can be 'built-in' to the kernel as well.
To boot the kernel directly from the firmware, the kernel image must be present on the EFI System Partition. This may be accomplished by enabling the efistub USE flag on sys-kernel/installkernel. Given that EFI Stub booting is not guaranteed to work on every UEFI system, the USE flag is stable masked, testing keywords must be accepted for installkernel to use this feature.
/etc/portage/package.accept_keywords/installkernel
sys-kernel/installkernel
sys-boot/uefi-mkconfig
app-emulation/virt-firmware
/etc/portage/package.use/installkernel
sys-kernel/installkernel efistub
Then reinstall installkernel, create the /efi/EFI/Gentoo directory and reinstall the kernel:
root #
emerge --ask sys-kernel/installkernel
root #
mkdir -p /efi/EFI/Gentoo
For distribution kernels:
root #
emerge --ask --config sys-kernel/gentoo-kernel{,-bin}
For manually managed kernels:
root #
make install
Alternatively, when installkernel is not used, the kernel may be copied manually to the EFI System Partition, calling it bzImage.efi:
root #
mkdir -p /efi/EFI/Gentoo
root #
cp /boot/vmlinuz-* /efi/EFI/Gentoo/bzImage.efi
Install the efibootmgr package:
root #
emerge --ask sys-boot/efibootmgr
Create boot entry called "Gentoo" for the freshly compiled EFI stub kernel within the UEFI firmware:
root #
efibootmgr --create --disk /dev/sda --part 1 --label "gentoo" --loader "\EFI\Gentoo\bzImage.efi"
The use of a backslash (\) as directory path separator is mandatory when using UEFI definitions.
Jeśli używany jest inicjalny system plików RAM (initramfs), dodaj do niego odpowiednią opcję rozruchu:
root #
efibootmgr -c -d /dev/sda -p 2 -L "Gentoo" -l "\efi\boot\bzImage.efi" initrd='\initramfs-genkernel-amd64-6.6.21-gentoo'
Additional kernel command line options may be parsed by the firmware to the kernel by specifying them along with the initrd=... option as shown above.
With these changes done, when the system reboots, a boot entry called "gentoo" will be available.
Unified Kernel Image
If installkernel was configured to build and install unified kernel images. The unified kernel image should already be installed to the EFI/Linux directory on the EFI system partition, if this is not the case ensure the directory exists and then run the kernel installation again as described earlier in the handbook.
To add a direct boot entry for the installed unified kernel image:
root #
efibootmgr --create --disk /dev/sda --part 1 --label "gentoo" --loader "\EFI\Linux\gentoo-x.y.z.efi"
Other Alternatives
For other options that are not covered in the Handbook, see the full list of available bootloaders.
Ponowne uruchomienie systemu
Wyjdź z środowiska chroot i odmontuj wszystkie zamontowane partycje. Następnie wpisz magiczne polecenie, które inicjuje ostateczny, prawdziwy test: reboot.
root #
exit
cdimage ~#
cd
cdimage ~#
umount -l /mnt/gentoo/dev{/shm,/pts,}
cdimage ~#
umount -R /mnt/gentoo
cdimage ~#
reboot
Nie zapomnij usunąć medium instalacyjnego, w przeciwnym razie zamiast nowego systemu Gentoo może zostać ponownie uruchomione medium instalacyjne.
Po uruchomieniu świeżo zainstalowanego środowiska Gentoo, kontynuuj Finalizowanie instalacji Gentoo.