;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2013, 2014 Ludovic Courtès <ludo@gnu.org>
;;;
;;; This file is part of GNU Guix.
;;;
;;; GNU Guix is free software; you can redistribute it and/or modify it
;;; under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 3 of the License, or (at
;;; your option) any later version.
;;;
;;; GNU Guix is distributed in the hope that it will be useful, but
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;;; GNU General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>.
(define-module (gnu system linux-initrd)
#:use-module (guix monads)
#:use-module (guix gexp)
#:use-module (guix utils)
#:use-module ((guix store)
#:select (%store-prefix))
#:use-module ((guix derivations)
#:select (derivation->output-path))
#:use-module (gnu packages cpio)
#:use-module (gnu packages compression)
#:use-module (gnu packages linux)
#:use-module (gnu packages guile)
#:use-module ((gnu packages make-bootstrap)
#:select (%guile-static-stripped))
#:use-module (gnu system file-systems)
#:use-module (ice-9 match)
#:use-module (ice-9 regex)
#:use-module (srfi srfi-1)
#:export (expression->initrd
base-initrd))
;;; Commentary:
;;;
;;; Tools to build initial RAM disks (initrd's) for Linux-Libre, and in
;;; particular initrd's that run Guile.
;;;
;;; Code:
(define* (expression->initrd exp
#:key
(guile %guile-static-stripped)
(cpio cpio)
(gzip gzip)
(name "guile-initrd")
(system (%current-system))
(modules '())
(to-copy '())
(linux #f)
(linux-modules '()))
"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'.
(define (string->regexp str)
;; Return a regexp that matches STR exactly.
(string-append "^" (regexp-quote str) "$"))
(mlet* %store-monad ((source (imported-modules modules))
(compiled (compiled-modules modules)))
(define builder
;; TODO: Move most of this code to (guix build linux-initrd).
#~(begin
(use-modules (guix build utils)
(ice-9 pretty-print)
(ice-9 popen)
(ice-9 match)
(ice-9 ftw)
(srfi srfi-26)
(system base compile)
(rnrs bytevectors)
((system foreign) #:select (sizeof)))
(let ((cpio (string-append #$cpio "/bin/cpio"))
(gzip (string-append #$gzip "/bin/gzip"))
(modules #$source)
(gos #$compiled)
(scm-dir (string-append "share/guile/" (effective-version)))
(go-dir (format #f ".cache/guile/ccache/~a-~a-~a-~a"
(effective-version)
(if (eq? (native-endianness) (endianness little))
"LE"
"BE")
(sizeof '*)
(effective-version))))
(mkdir #$output)
(mkdir "contents")
(with-directory-excursion "contents"
(copy-recursively #$guile ".")
(call-with-output-file "init"
(lambda (p)
(format p "#!/bin/guile -ds~%!#~%" #$guile)
(pretty-print '#$exp p)))
(chmod "init" #o555)
(chmod "bin/guile" #o555)
;; Copy Guile modules.
(chmod scm-dir #o777)
(copy-recursively modules scm-dir
#:follow-symlinks? #t)
(copy-recursively gos (string-append "lib/guile/"
(effective-version) "/ccache")
#:follow-symlinks? #t)
;; Compile `init'.
(mkdir-p go-dir)
(set! %load-path (cons modules %load-path))
(set! %load-compiled-path (cons gos %load-compiled-path))
(compile-file "init"
#:opts %auto-compilation-options
#:output-file (string-append go-dir "/init.go"))
;; Copy Linux modules.
(let* ((linux #$linux)
(module-dir (and linux
(string-append linux "/lib/modules"))))
(mkdir "modules")
#$@(map (lambda (module)
#~(match (find-files module-dir
#$(string->regexp module))
((file)
(format #t "copying '~a'...~%" file)
(copy-file file (string-append "modules/"
#$module)))
(()
(error "module not found" #$module module-dir))
((_ ...)
(error "several modules by that name"
#$module module-dir))))
linux-modules))
(let ((store #$(string-append "." (%store-prefix)))
(to-copy '#$to-copy))
(unless (null? to-copy)
(mkdir-p store))
;; XXX: Should we do export-references-graph?
(for-each (lambda (input)
(let ((target
(string-append store "/"
(basename input))))
(copy-recursively input target)))
to-copy))
;; Reset the timestamps of all the files that will make it in the
;; initrd.
(for-each (cut utime <> 0 0 0 0)
(find-files "." ".*"))
(system* cpio "--version")
(let ((pipe (open-pipe* OPEN_WRITE cpio "-o"
"-O" (string-append #$output "/initrd")
"-H" "newc" "--null")))
(define print0
(let ((len (string-length "./")))
(lambda (file)
(format pipe "~a\0" (string-drop file len)))))
;; Note: as per `ramfs-rootfs-initramfs.txt', always add
;; directory entries before the files that are inside of it: "The
;; Linux kernel cpio extractor won't create files in a directory
;; that doesn't exist, so the directory entries must go before
;; the files that go in those directories."
(file-system-fold (const #t)
(lambda (file stat result) ; leaf
(print0 file))
(lambda (dir stat result) ; down
(unless (string=? dir ".")
(print0 dir)))
(const #f) ; up
(const #f) ; skip
(const #f)
#f
".")
(and (zero? (close-pipe pipe))
(with-directory-excursion #$output
(and (zero? (system* gzip "--best" "initrd"))
(rename-file "initrd.gz" "initrd")))))))))
(gexp->derivation name builder
#:modules '((guix build utils)))))
(define (file-system->spec fs)
"Return a list corresponding to file-system FS that can be passed to the
initrd code."
(match fs
(($ <file-system> device title mount-point type flags options _ check?)
(list device title mount-point type flags options check?))))
(define* (base-initrd file-systems
#:key
qemu-networking?
virtio?
volatile-root?
(extra-modules '())
guile-modules-in-chroot?)
"Return a monadic derivation that builds a generic initrd. 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 '--root'.
When QEMU-NETWORKING? is true, set up networking with the standard QEMU
parameters. When VIRTIO? is true, load additional modules so the initrd can
be used as a QEMU guest with para-virtualized I/O drivers.
When 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 FILE-SYSTEMS and for the given options. However, additional kernel
modules can be listed in EXTRA-MODULES. They will be added to the initrd, and
loaded at boot time in the order in which they appear.
When GUILE-MODULES-IN-CHROOT? is true, make core Guile modules available in
the new root. This is necessary is the file specified as '--load' needs
access to these modules (which is the case if it wants to even just print an
exception and backtrace!)."
(define virtio-modules
;; Modules for Linux para-virtualized devices, for use in QEMU guests.
'("virtio.ko" "virtio_ring.ko" "virtio_pci.ko"
"virtio_balloon.ko" "virtio_blk.ko" "virtio_net.ko"))
(define cifs-modules
;; Modules needed to mount CIFS file systems.
'("md4.ko" "ecb.ko" "cifs.ko"))
(define virtio-9p-modules
;; Modules for the 9p paravirtualized file system.
'("9pnet.ko" "9p.ko" "9pnet_virtio.ko"))
(define (file-system-type-predicate type)
(lambda (fs)
(string=? (file-system-type fs) type)))
(define linux-modules
;; Modules added to the initrd and loaded from the initrd.
`("libahci.ko" "ahci.ko" ; modules for SATA controllers
,@(if (or virtio? qemu-networking?)
virtio-modules
'())
,@(if (find (file-system-type-predicate "cifs") file-systems)
cifs-modules
'())
,@(if (find (file-system-type-predicate "9p") file-systems)
virtio-9p-modules
'())
,@(if volatile-root?
'("fuse.ko")
'())
,@extra-modules))
(define helper-packages
;; Packages to be copied on the initrd.
`(,@(if (find (lambda (fs)
(string-prefix? "ext" (file-system-type fs)))
file-systems)
(list e2fsck/static)
'())
,@(if volatile-root?
(list unionfs-fuse/static)
'())))
(expression->initrd
#~(begin
(use-modules (guix build linux-initrd)
(guix build utils)
(srfi srfi-26))
(with-output-to-port (%make-void-port "w")
(lambda ()
(set-path-environment-variable "PATH" '("bin" "sbin")
'#$helper-packages)))
(boot-system #:mounts '#$(map file-system->spec file-systems)
#:linux-modules '#$linux-modules
#:qemu-guest-networking? #$qemu-networking?
#:guile-modules-in-chroot? '#$guile-modules-in-chroot?
#:volatile-root? '#$volatile-root?))
#:name "base-initrd"
#:modules '((guix build utils)
(guix build linux-initrd))
#:to-copy helper-packages
#:linux linux-libre
#:linux-modules linux-modules))
;;; linux-initrd.scm ends here