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88840f02 | 1 | ;;; GNU Guix --- Functional package management for GNU |
b97c95eb | 2 | ;;; Copyright © 2013, 2014 Ludovic Courtès <ludo@gnu.org> |
88840f02 LC |
3 | ;;; |
4 | ;;; This file is part of GNU Guix. | |
5 | ;;; | |
6 | ;;; GNU Guix is free software; you can redistribute it and/or modify it | |
7 | ;;; under the terms of the GNU General Public License as published by | |
8 | ;;; the Free Software Foundation; either version 3 of the License, or (at | |
9 | ;;; your option) any later version. | |
10 | ;;; | |
11 | ;;; GNU Guix is distributed in the hope that it will be useful, but | |
12 | ;;; WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | ;;; GNU General Public License for more details. | |
15 | ;;; | |
16 | ;;; You should have received a copy of the GNU General Public License | |
17 | ;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>. | |
18 | ||
19 | (define-module (guix build linux-initrd) | |
20 | #:use-module (rnrs io ports) | |
21 | #:use-module (system foreign) | |
d4254711 LC |
22 | #:autoload (system repl repl) (start-repl) |
23 | #:autoload (system base compile) (compile-file) | |
24 | #:use-module (srfi srfi-1) | |
25 | #:use-module (srfi srfi-26) | |
26 | #:use-module (ice-9 match) | |
44ddf33e | 27 | #:use-module (ice-9 ftw) |
d4254711 | 28 | #:use-module (guix build utils) |
88840f02 LC |
29 | #:export (mount-essential-file-systems |
30 | linux-command-line | |
d91712ee | 31 | make-essential-device-nodes |
88840f02 LC |
32 | configure-qemu-networking |
33 | mount-qemu-smb-share | |
4919d684 | 34 | mount-qemu-9p |
89bf140b | 35 | bind-mount |
88840f02 | 36 | load-linux-module* |
d4254711 LC |
37 | device-number |
38 | boot-system)) | |
88840f02 LC |
39 | |
40 | ;;; Commentary: | |
41 | ;;; | |
42 | ;;; Utility procedures useful in a Linux initial RAM disk (initrd). Note that | |
43 | ;;; many of these use procedures not yet available in vanilla Guile (`mount', | |
44 | ;;; `load-linux-module', etc.); these are provided by a Guile patch used in | |
45 | ;;; the GNU distribution. | |
46 | ;;; | |
47 | ;;; Code: | |
48 | ||
49 | (define* (mount-essential-file-systems #:key (root "/")) | |
50 | "Mount /proc and /sys under ROOT." | |
51 | (define (scope dir) | |
52 | (string-append root | |
53 | (if (string-suffix? "/" root) | |
54 | "" | |
55 | "/") | |
56 | dir)) | |
57 | ||
58 | (unless (file-exists? (scope "proc")) | |
59 | (mkdir (scope "proc"))) | |
60 | (mount "none" (scope "proc") "proc") | |
61 | ||
62 | (unless (file-exists? (scope "sys")) | |
63 | (mkdir (scope "sys"))) | |
64 | (mount "none" (scope "sys") "sysfs")) | |
65 | ||
66 | (define (linux-command-line) | |
67 | "Return the Linux kernel command line as a list of strings." | |
68 | (string-tokenize | |
69 | (call-with-input-file "/proc/cmdline" | |
70 | get-string-all))) | |
71 | ||
d91712ee LC |
72 | (define* (make-essential-device-nodes #:key (root "/")) |
73 | "Make essential device nodes under ROOT/dev." | |
74 | ;; The hand-made udev! | |
75 | ||
76 | (define (scope dir) | |
77 | (string-append root | |
78 | (if (string-suffix? "/" root) | |
79 | "" | |
80 | "/") | |
81 | dir)) | |
82 | ||
83 | (unless (file-exists? (scope "dev")) | |
84 | (mkdir (scope "dev"))) | |
85 | ||
fc4bc4b6 LC |
86 | ;; Make the device nodes for SCSI disks. |
87 | (mknod (scope "dev/sda") 'block-special #o644 (device-number 8 0)) | |
88 | (mknod (scope "dev/sda1") 'block-special #o644 (device-number 8 1)) | |
89 | (mknod (scope "dev/sda2") 'block-special #o644 (device-number 8 2)) | |
90 | ||
91 | ;; The virtio (para-virtualized) block devices, as supported by QEMU/KVM. | |
92 | (mknod (scope "dev/vda") 'block-special #o644 (device-number 252 0)) | |
93 | (mknod (scope "dev/vda1") 'block-special #o644 (device-number 252 1)) | |
94 | (mknod (scope "dev/vda2") 'block-special #o644 (device-number 252 2)) | |
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95 | |
96 | ;; TTYs. | |
29804e6e LC |
97 | (mknod (scope "dev/tty") 'char-special #o600 |
98 | (device-number 5 0)) | |
d91712ee LC |
99 | (let loop ((n 0)) |
100 | (and (< n 50) | |
101 | (let ((name (format #f "dev/tty~a" n))) | |
29804e6e | 102 | (mknod (scope name) 'char-special #o600 |
d91712ee LC |
103 | (device-number 4 n)) |
104 | (loop (+ 1 n))))) | |
105 | ||
37c825eb LC |
106 | ;; Rendez-vous point for syslogd. |
107 | (mknod (scope "dev/log") 'socket #o666 0) | |
108 | (mknod (scope "dev/kmsg") 'char-special #o600 (device-number 1 11)) | |
109 | ||
d91712ee LC |
110 | ;; Other useful nodes. |
111 | (mknod (scope "dev/null") 'char-special #o666 (device-number 1 3)) | |
b97c95eb LC |
112 | (mknod (scope "dev/zero") 'char-special #o666 (device-number 1 5)) |
113 | (chmod (scope "dev/null") #o666) | |
114 | (chmod (scope "dev/zero") #o666)) | |
d91712ee | 115 | |
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116 | (define %host-qemu-ipv4-address |
117 | (inet-pton AF_INET "10.0.2.10")) | |
118 | ||
119 | (define* (configure-qemu-networking #:optional (interface "eth0")) | |
120 | "Setup the INTERFACE network interface and /etc/resolv.conf according to | |
121 | QEMU's default networking settings (see net/slirp.c in QEMU for default | |
122 | networking values.) Return #t if INTERFACE is up, #f otherwise." | |
123 | (display "configuring QEMU networking...\n") | |
124 | (let* ((sock (socket AF_INET SOCK_STREAM 0)) | |
125 | (address (make-socket-address AF_INET %host-qemu-ipv4-address 0)) | |
126 | (flags (network-interface-flags sock interface))) | |
127 | (set-network-interface-address sock interface address) | |
128 | (set-network-interface-flags sock interface (logior flags IFF_UP)) | |
129 | ||
130 | (unless (file-exists? "/etc") | |
131 | (mkdir "/etc")) | |
132 | (call-with-output-file "/etc/resolv.conf" | |
133 | (lambda (p) | |
134 | (display "nameserver 10.0.2.3\n" p))) | |
135 | ||
136 | (logand (network-interface-flags sock interface) IFF_UP))) | |
137 | ||
138 | (define (mount-qemu-smb-share share mount-point) | |
139 | "Mount QEMU's CIFS/SMB SHARE at MOUNT-POINT. | |
140 | ||
141 | Vanilla QEMU's `-smb' option just exports a /qemu share, whereas our | |
142 | `qemu-with-multiple-smb-shares' package exports the /xchg and /store shares | |
143 | (the latter allows the store to be shared between the host and guest.)" | |
144 | ||
145 | (format #t "mounting QEMU's SMB share `~a'...\n" share) | |
146 | (let ((server "10.0.2.4")) | |
147 | (mount (string-append "//" server share) mount-point "cifs" 0 | |
148 | (string->pointer "guest,sec=none")))) | |
149 | ||
4919d684 LC |
150 | (define (mount-qemu-9p source mount-point) |
151 | "Mount QEMU's 9p file system from SOURCE at MOUNT-POINT. | |
152 | ||
153 | This uses the 'virtio' transport, which requires the various virtio Linux | |
154 | modules to be loaded." | |
155 | ||
156 | (format #t "mounting QEMU's 9p share '~a'...\n" source) | |
157 | (let ((server "10.0.2.4")) | |
158 | (mount source mount-point "9p" 0 | |
159 | (string->pointer "trans=virtio")))) | |
160 | ||
89bf140b LC |
161 | (define (bind-mount source target) |
162 | "Bind-mount SOURCE at TARGET." | |
163 | (define MS_BIND 4096) ; from libc's <sys/mount.h> | |
164 | ||
165 | (mount source target "" MS_BIND)) | |
166 | ||
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167 | (define (load-linux-module* file) |
168 | "Load Linux module from FILE, the name of a `.ko' file." | |
169 | (define (slurp module) | |
170 | (call-with-input-file file get-bytevector-all)) | |
171 | ||
172 | (load-linux-module (slurp file))) | |
173 | ||
174 | (define (device-number major minor) | |
175 | "Return the device number for the device with MAJOR and MINOR, for use as | |
176 | the last argument of `mknod'." | |
177 | (+ (* major 256) minor)) | |
178 | ||
d4254711 LC |
179 | (define* (boot-system #:key |
180 | (linux-modules '()) | |
181 | qemu-guest-networking? | |
182 | guile-modules-in-chroot? | |
44ddf33e | 183 | volatile-root? |
d4254711 LC |
184 | (mounts '())) |
185 | "This procedure is meant to be called from an initrd. Boot a system by | |
186 | first loading LINUX-MODULES, then setting up QEMU guest networking if | |
187 | QEMU-GUEST-NETWORKING? is true, mounting the file systems specified in MOUNTS, | |
188 | and finally booting into the new root if any. The initrd supports kernel | |
189 | command-line options '--load', '--root', and '--repl'. | |
190 | ||
191 | MOUNTS must be a list of elements of the form: | |
192 | ||
193 | (FILE-SYSTEM-TYPE SOURCE TARGET) | |
194 | ||
195 | When GUILE-MODULES-IN-CHROOT? is true, make core Guile modules available in | |
44ddf33e LC |
196 | the new root. |
197 | ||
198 | When VOLATILE-ROOT? is true, the root file system is writable but any changes | |
199 | to it are lost." | |
d4254711 LC |
200 | (define (resolve file) |
201 | ;; If FILE is a symlink to an absolute file name, resolve it as if we were | |
202 | ;; under /root. | |
203 | (let ((st (lstat file))) | |
204 | (if (eq? 'symlink (stat:type st)) | |
205 | (let ((target (readlink file))) | |
206 | (resolve (string-append "/root" target))) | |
207 | file))) | |
208 | ||
44ddf33e LC |
209 | (define MS_RDONLY 1) |
210 | ||
d4254711 LC |
211 | (display "Welcome, this is GNU's early boot Guile.\n") |
212 | (display "Use '--repl' for an initrd REPL.\n\n") | |
213 | ||
214 | (mount-essential-file-systems) | |
215 | (let* ((args (linux-command-line)) | |
216 | (option (lambda (opt) | |
217 | (let ((opt (string-append opt "="))) | |
218 | (and=> (find (cut string-prefix? opt <>) | |
219 | args) | |
220 | (lambda (arg) | |
221 | (substring arg (+ 1 (string-index arg #\=)))))))) | |
222 | (to-load (option "--load")) | |
223 | (root (option "--root"))) | |
224 | ||
225 | (when (member "--repl" args) | |
226 | (start-repl)) | |
227 | ||
228 | (display "loading kernel modules...\n") | |
229 | (for-each (compose load-linux-module* | |
230 | (cut string-append "/modules/" <>)) | |
231 | linux-modules) | |
232 | ||
233 | (when qemu-guest-networking? | |
234 | (unless (configure-qemu-networking) | |
235 | (display "network interface is DOWN\n"))) | |
236 | ||
237 | ;; Make /dev nodes. | |
238 | (make-essential-device-nodes) | |
239 | ||
240 | ;; Prepare the real root file system under /root. | |
241 | (unless (file-exists? "/root") | |
242 | (mkdir "/root")) | |
243 | (if root | |
83b9e6a1 LC |
244 | (catch #t |
245 | (lambda () | |
44ddf33e LC |
246 | (if volatile-root? |
247 | (begin | |
248 | ;; XXX: For lack of a union file system... | |
249 | (mkdir-p "/real-root") | |
250 | (mount root "/real-root" "ext3" MS_RDONLY) | |
251 | (mount "none" "/root" "tmpfs") | |
252 | ||
253 | ;; XXX: 'copy-recursively' cannot deal with device nodes, so | |
254 | ;; explicitly avoid /dev. | |
255 | (for-each (lambda (file) | |
256 | (unless (string=? "dev" file) | |
257 | (copy-recursively (string-append "/real-root/" | |
258 | file) | |
259 | (string-append "/root/" | |
260 | file) | |
261 | #:log (%make-void-port | |
262 | "w")))) | |
263 | (scandir "/real-root" | |
264 | (lambda (file) | |
265 | (not (member file '("." "..")))))) | |
266 | ||
267 | ;; TODO: Unmount /real-root. | |
268 | ) | |
269 | (mount root "/root" "ext3"))) | |
83b9e6a1 LC |
270 | (lambda args |
271 | (format (current-error-port) "exception while mounting '~a': ~s~%" | |
272 | root args) | |
273 | (start-repl))) | |
d4254711 | 274 | (mount "none" "/root" "tmpfs")) |
44ddf33e | 275 | |
d4254711 LC |
276 | (mount-essential-file-systems #:root "/root") |
277 | ||
278 | (unless (file-exists? "/root/dev") | |
279 | (mkdir "/root/dev") | |
280 | (make-essential-device-nodes #:root "/root")) | |
281 | ||
282 | ;; Mount the specified file systems. | |
283 | (for-each (match-lambda | |
284 | (('cifs source target) | |
285 | (let ((target (string-append "/root/" target))) | |
286 | (mkdir-p target) | |
287 | (mount-qemu-smb-share source target))) | |
4919d684 LC |
288 | (('9p source target) |
289 | (let ((target (string-append "/root/" target))) | |
290 | (mkdir-p target) | |
291 | (mount-qemu-9p source target)))) | |
d4254711 LC |
292 | mounts) |
293 | ||
294 | (when guile-modules-in-chroot? | |
295 | ;; Copy the directories that contain .scm and .go files so that the | |
296 | ;; child process in the chroot can load modules (we would bind-mount | |
297 | ;; them but for some reason that fails with EINVAL -- XXX). | |
298 | (mkdir-p "/root/share") | |
299 | (mkdir-p "/root/lib") | |
300 | (mount "none" "/root/share" "tmpfs") | |
301 | (mount "none" "/root/lib" "tmpfs") | |
302 | (copy-recursively "/share" "/root/share" | |
303 | #:log (%make-void-port "w")) | |
304 | (copy-recursively "/lib" "/root/lib" | |
305 | #:log (%make-void-port "w"))) | |
306 | ||
307 | (if to-load | |
308 | (begin | |
309 | (format #t "loading '~a'...\n" to-load) | |
310 | (chroot "/root") | |
311 | ;; TODO: Remove /lib, /share, and /loader.go. | |
312 | (catch #t | |
313 | (lambda () | |
314 | (primitive-load to-load)) | |
315 | (lambda args | |
316 | (format (current-error-port) "'~a' raised an exception: ~s~%" | |
317 | to-load args) | |
318 | (start-repl))) | |
319 | (format (current-error-port) | |
320 | "boot program '~a' terminated, rebooting~%" | |
321 | to-load) | |
322 | (sleep 2) | |
323 | (reboot)) | |
324 | (begin | |
325 | (display "no boot file passed via '--load'\n") | |
326 | (display "entering a warm and cozy REPL\n") | |
327 | (start-repl))))) | |
328 | ||
88840f02 | 329 | ;;; linux-initrd.scm ends here |