1SYSTEMD-BOOT(7) systemd-boot SYSTEMD-BOOT(7)
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6 systemd-boot, sd-boot - A simple UEFI boot manager
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9 systemd-boot (short: sd-boot) is a simple UEFI boot manager. It
10 provides a graphical menu to select the entry to boot and an editor for
11 the kernel command line. systemd-boot supports systems with UEFI
12 firmware only.
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14 systemd-boot loads boot entry information from the EFI system partition
15 (ESP), usually mounted at /boot, /efi, or /boot/efi during OS runtime.
16 Configuration file fragments, kernels, initrds and other EFI images to
17 boot generally need to reside on the ESP. Linux kernels must be built
18 with CONFIG_EFI_STUB to be able to be directly executed as an EFI
19 image. During boot systemd-boot automatically assembles a list of boot
20 entries from the following sources:
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22 · Boot entries defined with Boot Loader Specification[1] description
23 files located in /loader/entries/ on the ESP. These usually
24 describe Linux kernel images with associated initrd images, but
25 alternatively may also describe arbitrary other EFI executables.
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27 · Unified kernel images following the Boot Loader Specification[1],
28 as executable EFI binaries in /EFI/Linux/ on the ESP.
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30 · The Microsoft Windows EFI boot manager, if installed
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32 · The Apple MacOS X boot manager, if installed
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34 · The EFI Shell binary, if installed
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36 · A reboot into the UEFI firmware setup option, if supported by the
37 firmware
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39 kernel-install(8) may be used to copy kernel images onto the ESP and to
40 generate description files compliant with the Boot Loader
41 Specification. bootctl(1) may be used from a running system to locate
42 the ESP, list available entries, and install systemd-boot itself.
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44 systemd-boot will provide information about the time spent in UEFI
45 firmware using the Boot Loader Interface[2]. This information can be
46 displayed using systemd-analyze(1).
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49 The following keys may be used in the boot menu:
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51 ↑ (Up), ↓ (Down), j, k, PageUp, PageDown, Home, End
52 Navigate up/down in the entry list
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54 ↵ (Enter)
55 Boot selected entry
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57 d
58 Make selected entry the default
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60 e
61 Edit the kernel command line for selected entry
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63 +, t
64 Increase the timeout before default entry is booted
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66 -, T
67 Decrease the timeout
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69 v
70 Show systemd-boot, UEFI, and firmware versions
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72 P
73 Print status
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75 Q
76 Quit
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78 h, ?
79 Show a help screen
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81 Ctrl + l
82 Reprint the screen
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84 The following keys may be used during bootup or in the boot menu to
85 directly boot a specific entry:
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87 l
88 Linux
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90 w
91 Windows
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93 a
94 OS X
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96 s
97 EFI shell
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99 1, 2, 3, 4, 5, 6, 7, 8, 9
100 Boot entry number 1 ... 9
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102 In the editor, most keys simply insert themselves, but the following
103 keys may be used to perform additional actions:
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105 ← (Left), → (Right), Home, End
106 Navigate left/right
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108 Esc
109 Abort the edit and quit the editor
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111 Ctrl + k
112 Clear the command line
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114 Ctrl + w, Alt + Backspace
115 Delete word backwards
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117 Alt + d
118 Delete word forwards
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120 ↵ (Enter)
121 Boot entry with the edited command line
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123 Note that unless configured otherwise in the UEFI firmware,
124 systemd-boot will use the US keyboard layout, so key labels might not
125 match for keys like +/-.
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128 The files systemd-boot reads generally reside on the UEFI ESP which is
129 usually mounted to /boot/, /efi/ or /boot/efi during OS runtime.
130 systemd-boot reads runtime configuration such as the boot timeout and
131 default entry from /loader/loader.conf on the ESP (in combination with
132 data read from EFI variables). See loader.conf(5). Boot entry
133 description files following the Boot Loader Specification[1] are read
134 from /loader/entries/ on the ESP. Unified kernel boot entries following
135 the Boot Loader Specification[1] are read from /EFI/Linux/ on the ESP.
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138 bootctl(1), loader.conf(5), Boot Loader Specification[1], Boot Loader
139 Interface[2]
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142 1. Boot Loader Specification
143 https://github.com/systemd/systemd/blob/master/doc/BOOT_LOADER_SPECIFICATION.md
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145 2. Boot Loader Interface
146 https://www.freedesktop.org/wiki/Software/systemd/BootLoaderInterface
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150systemd 239 SYSTEMD-BOOT(7)