doc: Add "Initial RAM Disk" section.
* doc/guix.texi (Initial RAM Disk): New node. * gnu/system/linux-initrd.scm (expression->initrd): Adjust docstring.master
Ludovic Courtès
parent
a1906758c3
commit
fd1b1fa296
|
|
@ -2847,6 +2847,7 @@ instance to support new system services.
|
|||
* File Systems:: Configuring file system mounts.
|
||||
* User Accounts:: Specifying user accounts.
|
||||
* Services:: Specifying system services.
|
||||
* Initial RAM Disk:: Linux-Libre bootstrapping.
|
||||
* Invoking guix system:: Instantiating a system configuration.
|
||||
* Defining Services:: Adding new service definitions.
|
||||
@end menu
|
||||
|
|
@ -3259,6 +3260,76 @@ password. When @var{auto-login?} is true, log in automatically as
|
|||
@end deffn
|
||||
|
||||
|
||||
@node Initial RAM Disk
|
||||
@subsection Initial RAM Disk
|
||||
|
||||
@cindex initial RAM disk (initrd)
|
||||
@cindex initrd (initial RAM disk)
|
||||
For bootstrapping purposes, the Linux-Libre kernel is passed an
|
||||
@dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
|
||||
root file system, as well as an initialization script. The latter is
|
||||
responsible for mounting the real root file system, and for loading any
|
||||
kernel modules that may be needed to achieve that.
|
||||
|
||||
The @code{initrd} field of an @code{operating-system} declaration allows
|
||||
you to specify which initrd you would like to use. The @code{(gnu
|
||||
system linux-initrd)} module provides two ways to build an initrd: the
|
||||
high-level @code{base-initrd} procedure, and the low-level
|
||||
@code{expression->initrd} procedure.
|
||||
|
||||
The @code{base-initrd} procedure is intended to cover most common uses.
|
||||
For example, if you want to add a bunch of kernel modules to be loaded
|
||||
at boot time, you can define the @code{initrd} field of the operating
|
||||
system declaration like this:
|
||||
|
||||
@example
|
||||
(initrd (cut base-init <>
|
||||
#:extra-modules '("my.ko" "modules.ko")))
|
||||
@end example
|
||||
|
||||
It also handles common use cases that involves using the system as a
|
||||
QEMU guest, or as a ``live'' system whose root file system is volatile.
|
||||
|
||||
@deffn {Monadic Procedure} base-initrd @var{file-systems} @
|
||||
[#:qemu-networking? #f] [#:virtio? #f] [#:volatile-root? #f] @
|
||||
[#:extra-modules '()]
|
||||
Return a monadic derivation that builds a generic initrd. @var{file-systems} is
|
||||
a list of file-systems to be mounted by the initrd, possibly in addition to
|
||||
the root file system specified on the kernel command line via @code{--root}.
|
||||
|
||||
When @var{qemu-networking?} is true, set up networking with the standard QEMU
|
||||
parameters. When @var{virtio?} is true, load additional modules so the initrd can
|
||||
be used as a QEMU guest with para-virtualized I/O drivers.
|
||||
|
||||
When @var{volatile-root?} is true, the root file system is writable but any changes
|
||||
to it are lost.
|
||||
|
||||
The initrd is automatically populated with all the kernel modules necessary
|
||||
for @var{file-systems} and for the given options. However, additional kernel
|
||||
modules can be listed in @var{extra-modules}. They will be added to the initrd, and
|
||||
loaded at boot time in the order in which they appear.
|
||||
@end deffn
|
||||
|
||||
Needless to say, the initrds we produce and use embed a
|
||||
statically-linked Guile, and the initialization program is a Guile
|
||||
program. That gives a lot of flexibility. The
|
||||
@code{expression->initrd} procedure builds such an initrd, given the
|
||||
program to run in that initrd.
|
||||
|
||||
@deffn {Monadic Procedure} expression->initrd @var{exp} @
|
||||
[#:guile %guile-static-stripped] [#:name "guile-initrd"] @
|
||||
[#:modules '()] [#:to-copy '()] [#:linux #f] @
|
||||
[#:linux-modules '()]
|
||||
Return a derivation that builds a Linux initrd (a gzipped cpio archive)
|
||||
containing @var{guile} and that evaluates @var{exp}, a G-expression,
|
||||
upon booting.
|
||||
|
||||
@var{linux-modules} is a list of @file{.ko} file names to be copied from
|
||||
@var{linux} into the initrd. @var{to-copy} is a list of additional
|
||||
derivations or packages to copy to the initrd. @var{modules} is a list
|
||||
of Guile module names to be embedded in the initrd.
|
||||
@end deffn
|
||||
|
||||
@node Invoking guix system
|
||||
@subsection Invoking @code{guix system}
|
||||
|
||||
|
|
|
|||
|
|
@ -57,11 +57,13 @@
|
|||
(to-copy '())
|
||||
(linux #f)
|
||||
(linux-modules '()))
|
||||
"Return a package that contains a Linux initrd (a gzipped cpio archive)
|
||||
containing GUILE and that evaluates EXP upon booting. LINUX-MODULES is a list
|
||||
of `.ko' file names to be copied from LINUX into the initrd. TO-COPY is a
|
||||
list of additional derivations or packages to copy to the initrd. MODULES is
|
||||
a list of Guile module names to be embedded in the initrd."
|
||||
"Return a derivation that builds a Linux initrd (a gzipped cpio archive)
|
||||
containing GUILE and that evaluates EXP, a G-expression, upon booting.
|
||||
|
||||
LINUX-MODULES is a list of '.ko' file names to be copied from LINUX into the
|
||||
initrd. TO-COPY is a list of additional derivations or packages to copy to
|
||||
the initrd. MODULES is a list of Guile module names to be embedded in the
|
||||
initrd."
|
||||
|
||||
;; General Linux overview in `Documentation/early-userspace/README' and
|
||||
;; `Documentation/filesystems/ramfs-rootfs-initramfs.txt'.
|
||||
|
|
|
|||
Loading…
Reference in New Issue