;;; 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 utils)
#:use-module ((guix store)
#:select (%store-prefix))
#: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 (ice-9 regex)
#:export (expression->initrd
qemu-initrd
gnu-system-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 '())
(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. 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) "$"))
(define builder
`(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 ((guile (assoc-ref %build-inputs "guile"))
(cpio (string-append (assoc-ref %build-inputs "cpio")
"/bin/cpio"))
(gzip (string-append (assoc-ref %build-inputs "gzip")
"/bin/gzip"))
(modules (assoc-ref %build-inputs "modules"))
(gos (assoc-ref %build-inputs "modules/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)))
(out (assoc-ref %outputs "out")))
(mkdir out)
(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 (assoc-ref %build-inputs "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))
;; 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 out "/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 out
(and (zero? (system* gzip "--best" "initrd"))
(rename-file "initrd.gz" "initrd")))))))))
(mlet* %store-monad
((source (imported-modules modules))
(compiled (compiled-modules modules))
(inputs (lower-inputs
`(("guile" ,guile)
("cpio" ,cpio)
("gzip" ,gzip)
("modules" ,source)
("modules/compiled" ,compiled)
,@(if linux
`(("linux" ,linux))
'())))))
(derivation-expression name builder
#:modules '((guix build utils))
#:inputs inputs)))
(define* (qemu-initrd #:key
guile-modules-in-chroot?
volatile-root?
(mounts `((cifs "/store" ,(%store-prefix))
(cifs "/xchg" "/xchg"))))
"Return a monadic derivation that builds an initrd for use in a QEMU guest
where the store is shared with the host. MOUNTS is a list of file systems to
be mounted atop the root file system, where each item has the form:
(FILE-SYSTEM-TYPE SOURCE TARGET)
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!).
When VOLATILE-ROOT? is true, the root file system is writable but any changes
to it are lost."
(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 linux-modules
;; Modules added to the initrd and loaded from the initrd.
`("virtio.ko" "virtio_ring.ko" "virtio_pci.ko"
"virtio_balloon.ko" "virtio_blk.ko" "virtio_net.ko"
,@(if (assoc-ref mounts 'cifs)
cifs-modules
'())
,@(if (assoc-ref mounts '9p)
virtio-9p-modules
'())))
(expression->initrd
`(begin
(use-modules (guix build linux-initrd))
(boot-system #:mounts ',mounts
#:linux-modules ',linux-modules
#:qemu-guest-networking? #t
#:guile-modules-in-chroot? ',guile-modules-in-chroot?
#:volatile-root? ',volatile-root?))
#:name "qemu-initrd"
#:modules '((guix build utils)
(guix build linux-initrd))
#:linux linux-libre
#:linux-modules linux-modules))
(define (gnu-system-initrd)
"Initrd for the GNU system itself, with nothing QEMU-specific."
(qemu-initrd #:guile-modules-in-chroot? #f
#:mounts '()))
;;; linux-initrd.scm ends here