From d91712ee894e3bcaabc51269d292cbe77ed89530 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ludovic=20Court=C3=A8s?= <ludo@gnu.org>
Date: Sun, 1 Sep 2013 23:13:56 +0200
Subject: [PATCH] gnu: linux-initrd: Factorize device node creation.

* guix/build/linux-initrd.scm (make-essential-device-nodes): New
  procedure.
* gnu/packages/linux-initrd.scm (qemu-initrd): Use it.
---
 gnu/packages/linux-initrd.scm |  9 +++------
 guix/build/linux-initrd.scm   | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 35 insertions(+), 6 deletions(-)

diff --git a/gnu/packages/linux-initrd.scm b/gnu/packages/linux-initrd.scm
index 17f42652e8..4a4e437635 100644
--- a/gnu/packages/linux-initrd.scm
+++ b/gnu/packages/linux-initrd.scm
@@ -270,10 +270,8 @@ (define-public qemu-initrd
         (unless (configure-qemu-networking)
           (display "network interface is DOWN\n"))
 
-        ;; Make the device nodes for QEMU's hard disk and partitions.
-        (mknod "/dev/vda" 'block-special #o644 (device-number 8 0))
-        (mknod "/dev/vda1" 'block-special #o644 (device-number 8 1))
-        (mknod "/dev/vda2" 'block-special #o644 (device-number 8 2))
+        ;; Make /dev nodes.
+        (make-essential-device-nodes)
 
         ;; Prepare the real root file system under /root.
         (unless (file-exists? "/root")
@@ -287,8 +285,7 @@ (define-public qemu-initrd
         (mkdir-p "/root/nix/store")
 
         (mkdir "/root/dev")
-        (mknod "/root/dev/null" 'char-special #o666 (device-number 1 3))
-        (mknod "/root/dev/zero" 'char-special #o666 (device-number 1 5))
+        (make-essential-device-nodes #:root "/root/dev")
 
         ;; Mount the host's store and exchange directory.
         (mount-qemu-smb-share "/store" "/root/nix/store")
diff --git a/guix/build/linux-initrd.scm b/guix/build/linux-initrd.scm
index 81f9e46cfb..208ad711ef 100644
--- a/guix/build/linux-initrd.scm
+++ b/guix/build/linux-initrd.scm
@@ -21,6 +21,7 @@ (define-module (guix build linux-initrd)
   #: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
@@ -59,6 +60,37 @@ (define (linux-command-line)
    (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"))