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| author | Lennart Poettering <lennart@poettering.net> | 2022-09-23 15:10:06 +0200 |
|---|---|---|
| committer | Lennart Poettering <lennart@poettering.net> | 2022-09-23 15:12:18 +0200 |
| commit | 55c041b4e4dffad936522674d739a0affc08bdf4 (patch) | |
| tree | b0aef0c05053e157cd38b22008568014b000ca67 /docs/INITRD_INTERFACE.md | |
| parent | 32e276708089110243682d8aaa3d58075b91f0d6 (diff) | |
| download | systemd-55c041b4e4dffad936522674d739a0affc08bdf4.tar.gz | |
tree-wide: also settle on "initrd" instead of "initial RAM disk"
With this the concept is now called the same way everywhere except where
historical info is relevant or where the other names are API.
Diffstat (limited to 'docs/INITRD_INTERFACE.md')
| -rw-r--r-- | docs/INITRD_INTERFACE.md | 27 |
1 files changed, 14 insertions, 13 deletions
diff --git a/docs/INITRD_INTERFACE.md b/docs/INITRD_INTERFACE.md index 7e8f028ef8..6a54f9f7a6 100644 --- a/docs/INITRD_INTERFACE.md +++ b/docs/INITRD_INTERFACE.md @@ -8,15 +8,16 @@ SPDX-License-Identifier: LGPL-2.1-or-later # The initrd Interface of systemd -The Linux initrd mechanism (short for "initial RAM disk") refers to a small -file system archive that is unpacked by the kernel and contains the first -userspace code that runs. It typically finds and transitions into the actual -root file system to use. systemd supports both initrd and initrd-less boots. If -an initrd is used, it is a good idea to pass a few bits of runtime information -from the initrd to systemd in order to avoid duplicate work and to provide -performance data to the administrator. In this page we attempt to roughly -describe the interfaces that exist between the initrd and systemd. These -interfaces are currently used by dracut and the ArchLinux initrds. +The Linux initrd mechanism (short for "initial RAM disk", also known as +"initramfs") refers to a small file system archive that is unpacked by the +kernel and contains the first userspace code that runs. It typically finds and +transitions into the actual root file system to use. systemd supports both +initrd and initrd-less boots. If an initrd is used, it is a good idea to pass a +few bits of runtime information from the initrd to systemd in order to avoid +duplicate work and to provide performance data to the administrator. In this +page we attempt to roughly describe the interfaces that exist between the +initrd and systemd. These interfaces are currently used by dracut and the +ArchLinux initrds. * The initrd should mount `/run/` as a tmpfs and pass it pre-mounted when jumping into the main system when executing systemd. The mount options should @@ -57,10 +58,10 @@ It's all already implemented there! It is also possible and recommended to implement the initrd itself based on systemd. Here are a few terse notes: -* Provide `/etc/initrd-release` in the initrd image. The idea is that it follows - the same format as the usual `/etc/os-release` but describes the initial RAM - disk implementation rather than the OS. systemd uses the existence of this - file as a flag whether to run in initial RAM disk mode, or not. +* Provide `/etc/initrd-release` in the initrd image. The idea is that it + follows the same format as the usual `/etc/os-release` but describes the + initrd implementation rather than the OS. systemd uses the existence of this + file as a flag whether to run in initrd mode, or not. * When run in initrd mode, systemd and its components will read a couple of additional command line arguments, which are generally prefixed with `rd.` |