guix-devel/guix/build/linux-initrd.scm

147 lines
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;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2013 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 (guix build linux-initrd)
#:use-module (rnrs io ports)
#:use-module (system foreign)
#:export (mount-essential-file-systems
linux-command-line
make-essential-device-nodes
configure-qemu-networking
mount-qemu-smb-share
bind-mount
load-linux-module*
device-number))
;;; Commentary:
;;;
;;; Utility procedures useful in a Linux initial RAM disk (initrd). Note that
;;; many of these use procedures not yet available in vanilla Guile (`mount',
;;; `load-linux-module', etc.); these are provided by a Guile patch used in
;;; the GNU distribution.
;;;
;;; Code:
(define* (mount-essential-file-systems #:key (root "/"))
"Mount /proc and /sys under ROOT."
(define (scope dir)
(string-append root
(if (string-suffix? "/" root)
""
"/")
dir))
(unless (file-exists? (scope "proc"))
(mkdir (scope "proc")))
(mount "none" (scope "proc") "proc")
(unless (file-exists? (scope "sys"))
(mkdir (scope "sys")))
(mount "none" (scope "sys") "sysfs"))
(define (linux-command-line)
"Return the Linux kernel command line as a list of strings."
(string-tokenize
(call-with-input-file "/proc/cmdline"
get-string-all)))
(define* (make-essential-device-nodes #:key (root "/"))
"Make essential device nodes under ROOT/dev."
;; The hand-made udev!
(define (scope dir)
(string-append root
(if (string-suffix? "/" root)
""
"/")
dir))
(unless (file-exists? (scope "dev"))
(mkdir (scope "dev")))
;; Make the device nodes for QEMU's hard disk and partitions.
(mknod (scope "dev/vda") 'block-special #o644 (device-number 8 0))
(mknod (scope "dev/vda1") 'block-special #o644 (device-number 8 1))
(mknod (scope "dev/vda2") 'block-special #o644 (device-number 8 2))
;; TTYs.
(let loop ((n 0))
(and (< n 50)
(let ((name (format #f "dev/tty~a" n)))
(mknod (scope name) 'block-special #o644
(device-number 4 n))
(loop (+ 1 n)))))
;; Other useful nodes.
(mknod (scope "dev/null") 'char-special #o666 (device-number 1 3))
(mknod (scope "dev/zero") 'char-special #o666 (device-number 1 5)))
(define %host-qemu-ipv4-address
(inet-pton AF_INET "10.0.2.10"))
(define* (configure-qemu-networking #:optional (interface "eth0"))
"Setup the INTERFACE network interface and /etc/resolv.conf according to
QEMU's default networking settings (see net/slirp.c in QEMU for default
networking values.) Return #t if INTERFACE is up, #f otherwise."
(display "configuring QEMU networking...\n")
(let* ((sock (socket AF_INET SOCK_STREAM 0))
(address (make-socket-address AF_INET %host-qemu-ipv4-address 0))
(flags (network-interface-flags sock interface)))
(set-network-interface-address sock interface address)
(set-network-interface-flags sock interface (logior flags IFF_UP))
(unless (file-exists? "/etc")
(mkdir "/etc"))
(call-with-output-file "/etc/resolv.conf"
(lambda (p)
(display "nameserver 10.0.2.3\n" p)))
(logand (network-interface-flags sock interface) IFF_UP)))
(define (mount-qemu-smb-share share mount-point)
"Mount QEMU's CIFS/SMB SHARE at MOUNT-POINT.
Vanilla QEMU's `-smb' option just exports a /qemu share, whereas our
`qemu-with-multiple-smb-shares' package exports the /xchg and /store shares
(the latter allows the store to be shared between the host and guest.)"
(format #t "mounting QEMU's SMB share `~a'...\n" share)
(let ((server "10.0.2.4"))
(mount (string-append "//" server share) mount-point "cifs" 0
(string->pointer "guest,sec=none"))))
(define (bind-mount source target)
"Bind-mount SOURCE at TARGET."
(define MS_BIND 4096) ; from libc's <sys/mount.h>
(mount source target "" MS_BIND))
(define (load-linux-module* file)
"Load Linux module from FILE, the name of a `.ko' file."
(define (slurp module)
(call-with-input-file file get-bytevector-all))
(load-linux-module (slurp file)))
(define (device-number major minor)
"Return the device number for the device with MAJOR and MINOR, for use as
the last argument of `mknod'."
(+ (* major 256) minor))
;;; linux-initrd.scm ends here