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authorLudovic Courtès <ludo@gnu.org>2014-09-03 10:47:05 +0200
committerLudovic Courtès <ludo@gnu.org>2014-09-03 15:43:07 +0200
commit548f7a8fa2a4745d0e35e175e201513857440991 (patch)
tree5fa6118434b77716c93fac9ac2dac51ca257f807 /gnu/build/linux-initrd.scm
parent141360b5b257715fdca2db4fc106b4220788ae06 (diff)
downloadpatches-548f7a8fa2a4745d0e35e175e201513857440991.tar
patches-548f7a8fa2a4745d0e35e175e201513857440991.tar.gz
Move operating system helpers from (guix build …) to (gnu build …).
* guix/build/activation.scm, guix/build/install.scm, guix/build/linux-initrd.scm, guix/build/vm.scm: Move to... * gnu/build: ... here. * Makefile.am (MODULES): Remove the above guix/build/ files. * gnu-system.am (GNU_SYSTEM_MODULES): Add the above gnu/build/ files here. * gnu/services/base.scm, gnu/services/dmd.scm, gnu/system.scm, gnu/system/linux-initrd.scm, gnu/system/vm.scm, guix/scripts/system.scm: Adjust to the new module names.
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+;;; 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 build linux-initrd)
+ #:use-module (rnrs io ports)
+ #:use-module (rnrs bytevectors)
+ #:use-module (system foreign)
+ #:use-module (system repl error-handling)
+ #:autoload (system repl repl) (start-repl)
+ #:autoload (system base compile) (compile-file)
+ #:use-module (srfi srfi-1)
+ #:use-module (srfi srfi-26)
+ #:use-module (ice-9 match)
+ #:use-module (ice-9 rdelim)
+ #:use-module (ice-9 ftw)
+ #:use-module (guix build utils)
+ #:export (mount-essential-file-systems
+ linux-command-line
+ find-long-option
+ make-essential-device-nodes
+ configure-qemu-networking
+
+ disk-partitions
+ partition-label-predicate
+ find-partition-by-label
+ canonicalize-device-spec
+
+ mount-flags->bit-mask
+ check-file-system
+ mount-file-system
+ bind-mount
+
+ load-linux-module*
+ device-number
+ boot-system))
+
+;;; 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 (move-essential-file-systems root)
+ "Move currently mounted essential file systems to ROOT."
+ (for-each (lambda (dir)
+ (let ((target (string-append root dir)))
+ (unless (file-exists? target)
+ (mkdir target))
+ (mount dir target "" MS_MOVE)))
+ '("/proc" "/sys")))
+
+(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 (find-long-option option arguments)
+ "Find OPTION among ARGUMENTS, where OPTION is something like \"--load\".
+Return the value associated with OPTION, or #f on failure."
+ (let ((opt (string-append option "=")))
+ (and=> (find (cut string-prefix? opt <>)
+ arguments)
+ (lambda (arg)
+ (substring arg (+ 1 (string-index arg #\=)))))))
+
+(define-syntax %ext2-endianness
+ ;; Endianness of ext2 file systems.
+ (identifier-syntax (endianness little)))
+
+;; Offset in bytes of interesting parts of an ext2 superblock. See
+;; <http://www.nongnu.org/ext2-doc/ext2.html#DEF-SUPERBLOCK>.
+;; TODO: Use "packed structs" from Guile-OpenGL or similar.
+(define-syntax %ext2-sblock-magic (identifier-syntax 56))
+(define-syntax %ext2-sblock-creator-os (identifier-syntax 72))
+(define-syntax %ext2-sblock-uuid (identifier-syntax 104))
+(define-syntax %ext2-sblock-volume-name (identifier-syntax 120))
+
+(define (read-ext2-superblock device)
+ "Return the raw contents of DEVICE's ext2 superblock as a bytevector, or #f
+if DEVICE does not contain an ext2 file system."
+ (define %ext2-magic
+ ;; The magic bytes that identify an ext2 file system.
+ #xef53)
+
+ (define superblock-size
+ ;; Size of the interesting part of an ext2 superblock.
+ 264)
+
+ (define block
+ ;; The superblock contents.
+ (make-bytevector superblock-size))
+
+ (call-with-input-file device
+ (lambda (port)
+ (seek port 1024 SEEK_SET)
+
+ ;; Note: work around <http://bugs.gnu.org/17466>.
+ (and (eqv? superblock-size (get-bytevector-n! port block 0
+ superblock-size))
+ (let ((magic (bytevector-u16-ref block %ext2-sblock-magic
+ %ext2-endianness)))
+ (and (= magic %ext2-magic)
+ block))))))
+
+(define (ext2-superblock-uuid sblock)
+ "Return the UUID of ext2 superblock SBLOCK as a 16-byte bytevector."
+ (let ((uuid (make-bytevector 16)))
+ (bytevector-copy! sblock %ext2-sblock-uuid uuid 0 16)
+ uuid))
+
+(define (ext2-superblock-volume-name sblock)
+ "Return the volume name of SBLOCK as a string of at most 16 characters, or
+#f if SBLOCK has no volume name."
+ (let ((bv (make-bytevector 16)))
+ (bytevector-copy! sblock %ext2-sblock-volume-name bv 0 16)
+
+ ;; This is a Latin-1, nul-terminated string.
+ (let ((bytes (take-while (negate zero?) (bytevector->u8-list bv))))
+ (if (null? bytes)
+ #f
+ (list->string (map integer->char bytes))))))
+
+(define (disk-partitions)
+ "Return the list of device names corresponding to valid disk partitions."
+ (define (partition? major minor)
+ (let ((marker (format #f "/sys/dev/block/~a:~a/partition" major minor)))
+ (catch 'system-error
+ (lambda ()
+ (not (zero? (call-with-input-file marker read))))
+ (lambda args
+ (if (= ENOENT (system-error-errno args))
+ #f
+ (apply throw args))))))
+
+ (call-with-input-file "/proc/partitions"
+ (lambda (port)
+ ;; Skip the two header lines.
+ (read-line port)
+ (read-line port)
+
+ ;; Read each subsequent line, and extract the last space-separated
+ ;; field.
+ (let loop ((parts '()))
+ (let ((line (read-line port)))
+ (if (eof-object? line)
+ (reverse parts)
+ (match (string-tokenize line)
+ (((= string->number major) (= string->number minor)
+ blocks name)
+ (if (partition? major minor)
+ (loop (cons name parts))
+ (loop parts))))))))))
+
+(define (partition-label-predicate label)
+ "Return a procedure that, when applied to a partition name such as \"sda1\",
+return #t if that partition's volume name is LABEL."
+ (lambda (part)
+ (let* ((device (string-append "/dev/" part))
+ (sblock (catch 'system-error
+ (lambda ()
+ (read-ext2-superblock device))
+ (lambda args
+ ;; When running on the hand-made /dev,
+ ;; 'disk-partitions' could return partitions for which
+ ;; we have no /dev node. Handle that gracefully.
+ (if (= ENOENT (system-error-errno args))
+ (begin
+ (format (current-error-port)
+ "warning: device '~a' not found~%"
+ device)
+ #f)
+ (apply throw args))))))
+ (and sblock
+ (let ((volume (ext2-superblock-volume-name sblock)))
+ (and volume
+ (string=? volume label)))))))
+
+(define (find-partition-by-label label)
+ "Return the first partition found whose volume name is LABEL, or #f if none
+were found."
+ (and=> (find (partition-label-predicate label)
+ (disk-partitions))
+ (cut string-append "/dev/" <>)))
+
+(define* (canonicalize-device-spec spec #:optional (title 'any))
+ "Return the device name corresponding to SPEC. TITLE is a symbol, one of
+the following:
+
+ • 'device', in which case SPEC is known to designate a device node--e.g.,
+ \"/dev/sda1\";
+ • 'label', in which case SPEC is known to designate a partition label--e.g.,
+ \"my-root-part\";
+ • 'any', in which case SPEC can be anything.
+"
+ (define max-trials
+ ;; Number of times we retry partition label resolution, 1 second per
+ ;; trial. Note: somebody reported a delay of 16 seconds (!) before their
+ ;; USB key would be detected by the kernel, so we must wait for at least
+ ;; this long.
+ 20)
+
+ (define canonical-title
+ ;; The realm of canonicalization.
+ (if (eq? title 'any)
+ (if (string-prefix? "/" spec)
+ 'device
+ 'label)
+ title))
+
+ (case canonical-title
+ ((device)
+ ;; Nothing to do.
+ spec)
+ ((label)
+ ;; Resolve the label.
+ (let loop ((count 0))
+ (let ((device (find-partition-by-label spec)))
+ (or device
+ ;; Some devices take a bit of time to appear, most notably USB
+ ;; storage devices. Thus, wait for the device to appear.
+ (if (> count max-trials)
+ (error "failed to resolve partition label" spec)
+ (begin
+ (format #t "waiting for partition '~a' to appear...~%"
+ spec)
+ (sleep 1)
+ (loop (+ 1 count))))))))
+ ;; TODO: Add support for UUIDs.
+ (else
+ (error "unknown device title" title))))
+
+(define* (make-disk-device-nodes base major #:optional (minor 0))
+ "Make the block device nodes around BASE (something like \"/root/dev/sda\")
+with the given MAJOR number, starting with MINOR."
+ (mknod base 'block-special #o644 (device-number major minor))
+ (let loop ((i 1))
+ (when (< i 6)
+ (mknod (string-append base (number->string i))
+ 'block-special #o644 (device-number major (+ minor i)))
+ (loop (+ i 1)))))
+
+(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 SCSI disks.
+ (make-disk-device-nodes (scope "dev/sda") 8)
+ (make-disk-device-nodes (scope "dev/sdb") 8 16)
+ (make-disk-device-nodes (scope "dev/sdc") 8 32)
+ (make-disk-device-nodes (scope "dev/sdd") 8 48)
+
+ ;; SCSI CD-ROM devices (aka. "/dev/sr0" etc.).
+ (mknod (scope "dev/scd0") 'block-special #o644 (device-number 11 0))
+ (mknod (scope "dev/scd1") 'block-special #o644 (device-number 11 1))
+
+ ;; The virtio (para-virtualized) block devices, as supported by QEMU/KVM.
+ (make-disk-device-nodes (scope "dev/vda") 252)
+
+ ;; Memory (used by Xorg's VESA driver.)
+ (mknod (scope "dev/mem") 'char-special #o640 (device-number 1 1))
+ (mknod (scope "dev/kmem") 'char-special #o640 (device-number 1 2))
+
+ ;; Inputs (used by Xorg.)
+ (unless (file-exists? (scope "dev/input"))
+ (mkdir (scope "dev/input")))
+ (mknod (scope "dev/input/mice") 'char-special #o640 (device-number 13 63))
+ (mknod (scope "dev/input/mouse0") 'char-special #o640 (device-number 13 32))
+ (mknod (scope "dev/input/event0") 'char-special #o640 (device-number 13 64))
+
+ ;; System console. This node is magically created by the kernel on the
+ ;; initrd's root, so don't try to create it in that case.
+ (unless (string=? root "/")
+ (mknod (scope "dev/console") 'char-special #o600
+ (device-number 5 1)))
+
+ ;; TTYs.
+ (mknod (scope "dev/tty") 'char-special #o600
+ (device-number 5 0))
+ (chmod (scope "dev/tty") #o666)
+ (let loop ((n 0))
+ (and (< n 50)
+ (let ((name (format #f "dev/tty~a" n)))
+ (mknod (scope name) 'char-special #o600
+ (device-number 4 n))
+ (loop (+ 1 n)))))
+
+ ;; Serial line.
+ (mknod (scope "dev/ttyS0") 'char-special #o660
+ (device-number 4 64))
+
+ ;; Pseudo ttys.
+ (mknod (scope "dev/ptmx") 'char-special #o666
+ (device-number 5 2))
+ (chmod (scope "dev/ptmx") #o666)
+
+ ;; Create /dev/pts; it will be mounted later, at boot time.
+ (unless (file-exists? (scope "dev/pts"))
+ (mkdir (scope "dev/pts")))
+
+ ;; Rendez-vous point for syslogd.
+ (mknod (scope "dev/log") 'socket #o666 0)
+ (mknod (scope "dev/kmsg") 'char-special #o600 (device-number 1 11))
+
+ ;; Other useful nodes, notably relied on by guix-daemon.
+ (for-each (match-lambda
+ ((file major minor)
+ (mknod (scope file) 'char-special #o666
+ (device-number major minor))
+ (chmod (scope file) #o666)))
+ '(("dev/null" 1 3)
+ ("dev/zero" 1 5)
+ ("dev/full" 1 7)
+ ("dev/random" 1 8)
+ ("dev/urandom" 1 9)))
+
+ (symlink "/proc/self/fd" (scope "dev/fd"))
+ (symlink "/proc/self/fd/0" (scope "dev/stdin"))
+ (symlink "/proc/self/fd/1" (scope "dev/stdout"))
+ (symlink "/proc/self/fd/2" (scope "dev/stderr"))
+
+ ;; Loopback devices.
+ (let loop ((i 0))
+ (when (< i 8)
+ (mknod (scope (string-append "dev/loop" (number->string i)))
+ 'block-special #o660
+ (device-number 7 i))
+ (loop (+ 1 i))))
+
+ ;; File systems in user space (FUSE).
+ (mknod (scope "dev/fuse") 'char-special #o666 (device-number 10 229)))
+
+(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))
+
+ ;; Hello! We used to create /etc/resolv.conf here, with "nameserver
+ ;; 10.0.2.3\n". However, with Linux-libre 3.16, we're getting ENOSPC.
+ ;; And since it's actually unnecessary, it's gone.
+
+ (logand (network-interface-flags sock interface) IFF_UP)))
+
+;; Linux mount flags, from libc's <sys/mount.h>.
+(define MS_RDONLY 1)
+(define MS_NOSUID 2)
+(define MS_NODEV 4)
+(define MS_NOEXEC 8)
+(define MS_BIND 4096)
+(define MS_MOVE 8192)
+
+(define (bind-mount source target)
+ "Bind-mount SOURCE at TARGET."
+ (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))
+
+(define (pidof program)
+ "Return the PID of the first presumed instance of PROGRAM."
+ (let ((program (basename program)))
+ (find (lambda (pid)
+ (let ((exe (format #f "/proc/~a/exe" pid)))
+ (and=> (false-if-exception (readlink exe))
+ (compose (cut string=? program <>) basename))))
+ (filter-map string->number (scandir "/proc")))))
+
+(define* (mount-root-file-system root type
+ #:key volatile-root? (unionfs "unionfs"))
+ "Mount the root file system of type TYPE at device ROOT. If VOLATILE-ROOT?
+is true, mount ROOT read-only and make it a union with a writable tmpfs using
+UNIONFS."
+ (define (mark-as-not-killable pid)
+ ;; Tell the 'user-processes' dmd service that PID must be kept alive when
+ ;; shutting down.
+ (mkdir-p "/root/etc/dmd")
+ (let ((port (open-file "/root/etc/dmd/do-not-kill" "a")))
+ (chmod port #o600)
+ (write pid port)
+ (newline port)
+ (close-port port)))
+
+ (catch #t
+ (lambda ()
+ (if volatile-root?
+ (begin
+ (mkdir-p "/real-root")
+ (mount root "/real-root" type MS_RDONLY)
+ (mkdir-p "/rw-root")
+ (mount "none" "/rw-root" "tmpfs")
+
+ ;; We want read-write /dev nodes.
+ (make-essential-device-nodes #:root "/rw-root")
+
+ ;; Make /root a union of the tmpfs and the actual root. Use
+ ;; 'max_files' to set a high RLIMIT_NOFILE for the unionfs process
+ ;; itself. Failing to do that, we quickly run out of file
+ ;; descriptors; see <http://bugs.gnu.org/17827>.
+ (unless (zero? (system* unionfs "-o"
+ "cow,allow_other,use_ino,suid,dev,max_files=65536"
+ "/rw-root=RW:/real-root=RO"
+ "/root"))
+ (error "unionfs failed"))
+
+ ;; Make sure unionfs remains alive till the end. Because
+ ;; 'fuse_daemonize' doesn't tell the PID of the forked daemon, we
+ ;; have to resort to 'pidof' here.
+ (mark-as-not-killable (pidof unionfs)))
+ (begin
+ (check-file-system root type)
+ (mount root "/root" type))))
+ (lambda args
+ (format (current-error-port) "exception while mounting '~a': ~s~%"
+ root args)
+ (start-repl)))
+
+ (copy-file "/proc/mounts" "/root/etc/mtab"))
+
+(define (check-file-system device type)
+ "Run a file system check of TYPE on DEVICE."
+ (define fsck
+ (string-append "fsck." type))
+
+ (let ((status (system* fsck "-v" "-p" device)))
+ (match (status:exit-val status)
+ (0
+ #t)
+ (1
+ (format (current-error-port) "'~a' corrected errors on ~a; continuing~%"
+ fsck device))
+ (2
+ (format (current-error-port) "'~a' corrected errors on ~a; rebooting~%"
+ fsck device)
+ (sleep 3)
+ (reboot))
+ (code
+ (format (current-error-port) "'~a' exited with code ~a on ~a; spawning REPL~%"
+ fsck code device)
+ (start-repl)))))
+
+(define (mount-flags->bit-mask flags)
+ "Return the number suitable for the 'flags' argument of 'mount' that
+corresponds to the symbols listed in FLAGS."
+ (let loop ((flags flags))
+ (match flags
+ (('read-only rest ...)
+ (logior MS_RDONLY (loop rest)))
+ (('bind-mount rest ...)
+ (logior MS_BIND (loop rest)))
+ (('no-suid rest ...)
+ (logior MS_NOSUID (loop rest)))
+ (('no-dev rest ...)
+ (logior MS_NODEV (loop rest)))
+ (('no-exec rest ...)
+ (logior MS_NOEXEC (loop rest)))
+ (()
+ 0))))
+
+(define* (mount-file-system spec #:key (root "/root"))
+ "Mount the file system described by SPEC under ROOT. SPEC must have the
+form:
+
+ (DEVICE TITLE MOUNT-POINT TYPE (FLAGS ...) OPTIONS CHECK?)
+
+DEVICE, MOUNT-POINT, and TYPE must be strings; OPTIONS can be a string or #f;
+FLAGS must be a list of symbols. CHECK? is a Boolean indicating whether to
+run a file system check."
+ (match spec
+ ((source title mount-point type (flags ...) options check?)
+ (let ((source (canonicalize-device-spec source title))
+ (mount-point (string-append root "/" mount-point)))
+ (when check?
+ (check-file-system source type))
+ (mkdir-p mount-point)
+ (mount source mount-point type (mount-flags->bit-mask flags)
+ (if options
+ (string->pointer options)
+ %null-pointer))
+
+ ;; Update /etc/mtab.
+ (mkdir-p (string-append root "/etc"))
+ (let ((port (open-file (string-append root "/etc/mtab") "a")))
+ (format port "~a ~a ~a ~a 0 0~%"
+ source mount-point type (or options ""))
+ (close-port port))))))
+
+(define (switch-root root)
+ "Switch to ROOT as the root file system, in a way similar to what
+util-linux' switch_root(8) does."
+ (move-essential-file-systems root)
+ (chdir root)
+
+ ;; Since we're about to 'rm -rf /', try to make sure we're on an initrd.
+ ;; TODO: Use 'statfs' to check the fs type, like klibc does.
+ (when (or (not (file-exists? "/init")) (directory-exists? "/home"))
+ (format (current-error-port)
+ "The root file system is probably not an initrd; \
+bailing out.~%root contents: ~s~%" (scandir "/"))
+ (force-output (current-error-port))
+ (exit 1))
+
+ ;; Delete files from the old root, without crossing mount points (assuming
+ ;; there are no mount points in sub-directories.) That means we're leaving
+ ;; the empty ROOT directory behind us, but that's OK.
+ (let ((root-device (stat:dev (stat "/"))))
+ (for-each (lambda (file)
+ (unless (member file '("." ".."))
+ (let* ((file (string-append "/" file))
+ (device (stat:dev (lstat file))))
+ (when (= device root-device)
+ (delete-file-recursively file)))))
+ (scandir "/")))
+
+ ;; Make ROOT the new root.
+ (mount root "/" "" MS_MOVE)
+ (chroot ".")
+ (chdir "/")
+
+ (when (file-exists? "/dev/console")
+ ;; Close the standard file descriptors since they refer to the old
+ ;; /dev/console, and reopen them.
+ (let ((console (open-file "/dev/console" "r+b0")))
+ (for-each close-fdes '(0 1 2))
+
+ (dup2 (fileno console) 0)
+ (dup2 (fileno console) 1)
+ (dup2 (fileno console) 2)
+
+ (close-port console))))
+
+
+(define* (boot-system #:key
+ (linux-modules '())
+ qemu-guest-networking?
+ guile-modules-in-chroot?
+ volatile-root?
+ (mounts '()))
+ "This procedure is meant to be called from an initrd. Boot a system by
+first loading LINUX-MODULES, then setting up QEMU guest networking if
+QEMU-GUEST-NETWORKING? is true, mounting the file systems specified in MOUNTS,
+and finally booting into the new root if any. The initrd supports kernel
+command-line options '--load', '--root', and '--repl'.
+
+Mount the root file system, specified by the '--root' command-line argument,
+if any.
+
+MOUNTS must be a list suitable for 'mount-file-system'.
+
+When GUILE-MODULES-IN-CHROOT? is true, make core Guile modules available in
+the new root.
+
+When VOLATILE-ROOT? is true, the root file system is writable but any changes
+to it are lost."
+ (define root-mount-point?
+ (match-lambda
+ ((device _ "/" _ ...) #t)
+ (_ #f)))
+
+ (define root-fs-type
+ (or (any (match-lambda
+ ((device _ "/" type _ ...) type)
+ (_ #f))
+ mounts)
+ "ext4"))
+
+ (display "Welcome, this is GNU's early boot Guile.\n")
+ (display "Use '--repl' for an initrd REPL.\n\n")
+
+ (call-with-error-handling
+ (lambda ()
+ (mount-essential-file-systems)
+ (let* ((args (linux-command-line))
+ (to-load (find-long-option "--load" args))
+ (root (find-long-option "--root" args)))
+
+ (when (member "--repl" args)
+ (start-repl))
+
+ (display "loading kernel modules...\n")
+ (for-each (compose load-linux-module*
+ (cut string-append "/modules/" <>))
+ linux-modules)
+
+ (when qemu-guest-networking?
+ (unless (configure-qemu-networking)
+ (display "network interface is DOWN\n")))
+
+ ;; Make /dev nodes.
+ (make-essential-device-nodes)
+
+ ;; Prepare the real root file system under /root.
+ (unless (file-exists? "/root")
+ (mkdir "/root"))
+ (if root
+ (mount-root-file-system (canonicalize-device-spec root)
+ root-fs-type
+ #:volatile-root? volatile-root?)
+ (mount "none" "/root" "tmpfs"))
+
+ (unless (file-exists? "/root/dev")
+ (mkdir "/root/dev")
+ (make-essential-device-nodes #:root "/root"))
+
+ ;; Mount the specified file systems.
+ (for-each mount-file-system
+ (remove root-mount-point? mounts))
+
+ (when guile-modules-in-chroot?
+ ;; Copy the directories that contain .scm and .go files so that the
+ ;; child process in the chroot can load modules (we would bind-mount
+ ;; them but for some reason that fails with EINVAL -- XXX).
+ (mkdir-p "/root/share")
+ (mkdir-p "/root/lib")
+ (mount "none" "/root/share" "tmpfs")
+ (mount "none" "/root/lib" "tmpfs")
+ (copy-recursively "/share" "/root/share"
+ #:log (%make-void-port "w"))
+ (copy-recursively "/lib" "/root/lib"
+ #:log (%make-void-port "w")))
+
+ (if to-load
+ (begin
+ (switch-root "/root")
+ (format #t "loading '~a'...\n" to-load)
+
+ ;; TODO: Remove /lib, /share, and /loader.go.
+ (primitive-load to-load)
+
+ (format (current-error-port)
+ "boot program '~a' terminated, rebooting~%"
+ to-load)
+ (sleep 2)
+ (reboot))
+ (begin
+ (display "no boot file passed via '--load'\n")
+ (display "entering a warm and cozy REPL\n")
+ (start-repl)))))))
+
+;;; linux-initrd.scm ends here