* 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
This commit is contained in:
Eelco Dolstra 2004-02-14 22:56:51 +00:00
commit e019265ec9
4 changed files with 107 additions and 0 deletions

4
bootstrap.nix Normal file
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let {
pkgs = import pkgs/system/i686-linux.nix;
body = pkgs.bash;
}

64
fill-disk.sh Executable file
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#! /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

34
make-disk.sh Executable file
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#! /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"

5
run.sh Executable file
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#! /bin/sh -e
image=/tmp/disk.img
linux ubd0=$image init="/init"