From e019265ec958f836b0290d07afbf5fe2e1c3d14a Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <eelco.dolstra@logicblox.com>
Date: Sat, 14 Feb 2004 22:56:51 +0000
Subject: [PATCH] * Scripts to set up and run the absolute minimal pure Nix  
 environment; that is, an operating system environment in which there   is
 (essentially) only a store.

  The script `make-disk.sh' creates an ext2 disk image, creates a Nix
  store in it, and copies the closure of the bash package (from
  nixpkgs) to it.  The script `run.sh' then starts bash in a UML
  virtual machine.

  The contents of the image after creation look like this:

  $ ls -l
  drwxr-xr-x    2 root     root         1024 2004-02-14 19:13 dev
  lrwxrwxrwx    1 root     root           61 2004-02-14 23:34 init -> /nix/store/e40873ece7a010752ad72b4262b23d28-bash-2.05b/bin/sh
  drwx------    2 root     root        12288 2004-02-14 19:13 lost+found
  drwxr-xr-x    4 root     root         1024 2004-02-14 19:13 nix
  drwxr-xr-x    2 root     root         1024 2004-02-14 19:13 proc
  drwxrwxrwt    2 root     root         1024 2004-02-14 19:13 tmp

  The next step is to add all the other stuff that goes into a working
  system (coreutils, etc.).  BTW, if you don't have `ls' you can still
  list directories by doing `echo *' :-)

  Nix itself should also be Nixified so that it can be put into the
  store.

svn path=/nixu/trunk/; revision=783
---
 bootstrap.nix |  4 ++++
 fill-disk.sh  | 64 +++++++++++++++++++++++++++++++++++++++++++++++++++
 make-disk.sh  | 34 +++++++++++++++++++++++++++
 run.sh        |  5 ++++
 4 files changed, 107 insertions(+)
 create mode 100644 bootstrap.nix
 create mode 100755 fill-disk.sh
 create mode 100755 make-disk.sh
 create mode 100755 run.sh

diff --git a/bootstrap.nix b/bootstrap.nix
new file mode 100644
index 000000000000..bd141c96ff8a
--- /dev/null
+++ b/bootstrap.nix
@@ -0,0 +1,4 @@
+let {
+  pkgs = import pkgs/system/i686-linux.nix;
+  body = pkgs.bash;
+}
\ No newline at end of file
diff --git a/fill-disk.sh b/fill-disk.sh
new file mode 100755
index 000000000000..8c09c788e9d9
--- /dev/null
+++ b/fill-disk.sh
@@ -0,0 +1,64 @@
+#! /bin/sh -e
+
+initExpr=$1
+
+make_dir() {
+    mode=$1
+    name=$2
+    echo creating $name...
+    if ! test -d $root/$name; then mkdir $root/$name; fi
+    chmod $mode $root/$name
+}
+
+root=/tmp/mnt
+
+echo mounting...
+mount -t ext2 /dev/discs/disc0/disc $root
+
+make_dir 00755 /dev
+make_dir 00755 /proc
+make_dir 01777 /tmp
+make_dir 00755 /nix
+make_dir 00755 /nix/store
+make_dir 00755 /nix/var
+make_dir 00755 /nix/var/nix
+make_dir 00755 /nix/var/nix/db
+make_dir 00755 /nix/var/log
+make_dir 00755 /nix/var/log/nix
+
+export NIX_ROOT=$root
+
+echo initialising Nix DB...
+/nix/bin/nix-store --init
+
+echo verifying Nix DB...
+/nix/bin/nix-store --verify
+
+echo registering valid paths...
+(while read storepath; do
+    echo PATH $storepath
+    if ! /nix/bin/nix-store --isvalid $storepath 2> /dev/null; then
+        (unset NIX_ROOT; /nix/bin/nix-store --dump $storepath) | /nix/bin/nix-store --restore $storepath
+        /nix/bin/nix-store --validpath $storepath
+    fi
+done) < /tmp/storepaths
+
+echo registering successors...
+(while read line; do
+    echo SUCC $line
+    /nix/bin/nix-store --successor $line
+done) < /tmp/successors
+
+echo setting init symlink...
+initPath=$(/nix/bin/nix-store -qn $initExpr)
+rm -f $root/init
+ln -s $initPath/bin/sh $root/init
+
+echo unmounting...
+umount $root
+
+echo syncing...
+sync
+
+echo halting...
+/sbin/halt -d -f
diff --git a/make-disk.sh b/make-disk.sh
new file mode 100755
index 000000000000..e891159f9e8a
--- /dev/null
+++ b/make-disk.sh
@@ -0,0 +1,34 @@
+#! /bin/sh -e
+
+image=/tmp/disk.img
+size=$(expr 256 \* 1024 \* 1024)
+storepaths=/tmp/storepaths
+successors=/tmp/successors
+
+if ! test -f $image; then 
+
+    echo creating empty disk of $size bytes in $image...
+    # Note: this is a sparse file.
+    dd if=/dev/zero of=$image bs=1 seek=$(expr $size - 1) count=1
+
+    echo creating disk image in $image...
+    /sbin/mke2fs -F $image
+
+fi
+
+
+# What to copy?
+storeexpr=$(nix-instantiate ./bootstrap.nix)
+nix-store -rB $storeexpr
+nix-store -qn --requisites $storeexpr > $storepaths
+
+(while read storepath; do
+  nix-store -q --predecessors $storepath | (while read predecessor; do
+    echo $predecessor $storepath
+  done) 
+done) < $storepaths > $successors
+
+# Fill the disk with the minimal Nix store.
+if ! test -d /tmp/mnt; then mkdir /tmp/mnt; fi
+linux ubd0=$image root=/dev/root rootflags=/ rootfstype=hostfs init="$(pwd)/fill-disk.sh $storeexpr"
+
diff --git a/run.sh b/run.sh
new file mode 100755
index 000000000000..19c329f67b1f
--- /dev/null
+++ b/run.sh
@@ -0,0 +1,5 @@
+#! /bin/sh -e
+
+image=/tmp/disk.img
+
+linux ubd0=$image init="/init"