SYSTEMD-BOOT(7) systemd-boot SYSTEMD-BOOT(7)
NAME
systemd-boot, sd-boot - A simple UEFI boot manager
DESCRIPTION
systemd-boot (short: sd-boot) is a simple UEFI boot manager. It
provides a graphical menu to select the entry to boot and an editor for
the kernel command line. systemd-boot supports systems with UEFI
firmware only.
systemd-boot loads boot entry information from the EFI system partition
(ESP), usually mounted at /boot, /efi, or /boot/efi during OS runtime.
Configuration file fragments, kernels, initrds and other EFI images to
boot generally need to reside on the ESP. Linux kernels must be built
with CONFIG_EFI_STUB to be able to be directly executed as an EFI
image. During boot systemd-boot automatically assembles a list of boot
entries from the following sources:
o Boot entries defined with Boot Loader Specification[1] description
files located in /loader/entries/ on the ESP. These usually
describe Linux kernel images with associated initrd images, but
alternatively may also describe arbitrary other EFI executables.
o Unified kernel images following the Boot Loader Specification[1],
as executable EFI binaries in /EFI/Linux/ on the ESP.
o The Microsoft Windows EFI boot manager, if installed
o The Apple MacOS X boot manager, if installed
o The EFI Shell binary, if installed
o A reboot into the UEFI firmware setup option, if supported by the
firmware
kernel-install(8) may be used to copy kernel images onto the ESP and to
generate description files compliant with the Boot Loader
Specification. bootctl(1) may be used from a running system to locate
the ESP, list available entries, and install systemd-boot itself.
systemd-boot will provide information about the time spent in UEFI
firmware using the Boot Loader Interface[2]. This information can be
displayed using systemd-analyze(1).
KEY BINDINGS
The following keys may be used in the boot menu:
^ (Up), v (Down), j, k, PageUp, PageDown, Home, End
Navigate up/down in the entry list
_| (Enter)
Boot selected entry
d
Make selected entry the default
e
Edit the kernel command line for selected entry
+, t
Increase the timeout before default entry is booted
-, T
Decrease the timeout
v
Show systemd-boot, UEFI, and firmware versions
P
Print status
Q
Quit
h, ?
Show a help screen
Ctrl + l
Reprint the screen
The following keys may be used during bootup or in the boot menu to
directly boot a specific entry:
l
Linux
w
Windows
a
OS X
s
EFI shell
1, 2, 3, 4, 5, 6, 7, 8, 9
Boot entry number 1 ... 9
In the editor, most keys simply insert themselves, but the following
keys may be used to perform additional actions:
<- (Left), -> (Right), Home, End
Navigate left/right
Esc
Abort the edit and quit the editor
Ctrl + k
Clear the command line
Ctrl + w, Alt + Backspace
Delete word backwards
Alt + d
Delete word forwards
_| (Enter)
Boot entry with the edited command line
Note that unless configured otherwise in the UEFI firmware,
systemd-boot will use the US keyboard layout, so key labels might not
match for keys like +/-.
FILES
The files systemd-boot reads generally reside on the UEFI ESP which is
usually mounted to /boot/, /efi/ or /boot/efi during OS runtime.
systemd-boot reads runtime configuration such as the boot timeout and
default entry from /loader/loader.conf on the ESP (in combination with
data read from EFI variables). See loader.conf(5). Boot entry
description files following the Boot Loader Specification[1] are read
from /loader/entries/ on the ESP. Unified kernel boot entries following
the Boot Loader Specification[1] are read from /EFI/Linux/ on the ESP.
SEE ALSO
bootctl(1), loader.conf(5), Boot Loader Specification[1], Boot Loader
Interface[2]
NOTES
1. Boot Loader Specification
https://github.com/systemd/systemd/blob/master/doc/BOOT_LOADER_SPECIFICATION.md
2. Boot Loader Interface
https://www.freedesktop.org/wiki/Software/systemd/BootLoaderInterface
systemd 239 SYSTEMD-BOOT(7)