Spork Bomb

That's right, MPDDP 2 is now functionally complete, it can do everything that regular MPDDP can, and more. The downside is that, currently, it's incredibly slow to start up, but I'm thinking of a solution for that.The whole routine for checking if a track is allowed by the rule is fairly inefficient currently, so that'll likely be rewritten completely soon and, for ease of parsing, I might change the rule syntax to S-expressions. Perhaps a MPDDP 2.1 already?

Barrucadu's Guide to MPDDP Version Numbers

Which number has changed?

• X.y.z: everything has changed completely. Your configuration file definitely won't work.
• x.Y.z: something big has changed more-or-less completely. Your configuration file probably won't work
• x.y.Z: something has changed, but not really that much; probably just a bugfix. Your configuration file should be fine.

Configuration

MPDDP 2 has a completely different configuration syntax to MPDDP, here's an example:

MPDDP

server = localhost
path:fred/

Connect to the MPD server at localhost and use all tracks in the path fred/.

MPDDP 2

rule fred {
    path ~= "fred/"
}
host localhost
active fred

Connect to the MPD server at localhost, and use the rule fred, which matches all tracks with a path containing fred/.

While these two examples are functionally equivalent, the MPDDP 2 example is longer. In fact, my MPDDP 2 config file is a lot longer than my MPDDP config file, but that's because currently it's a direct translation of my MPDDP config file to MPDDP 2 syntax, and I'm not using many MPDDP 2 specific features yet. However, MPDDP 2 can do things that regular MPDDP can't, or can only do using the MPDSPL integration (which has been removed from MPDDP 2). Consider the following, for example:

rule firstfred {
    artist = "fred"
    album = "first"
}

A rule which matches all tracks by "fred" in the album "first", or the following:

rule fg {
    artist = "fred" or \
    artist = "george"
}

A rule which matches all tracks by "fred" or "george". Also, note that I split the line into two by putting a backslash before the newline. You can escape newlines like that anywhere in the config file. I suppose that's enough examples for now, now I shall go into more detail about how the rules work.

Rules

Each rule is more correctly known as a ruleset. Each ruleset is broken up into several rules (one line = one rule), and each rule is broken up into several conditions (eg: 'artist = "fred"'). A track matches the ruleset if it matches all of the rules.

Conditions have two forms, the first takes three parameters, the second only one.

'Normal' Conditions

These conditions are in the form "keyword comparison value" (or "value comparison keyword" (or even "keyword comparison keyword", or "value comparison value")), where the keyword is one of the following:

• artist
• album
• title
• path
• file
• genre
• time

Comparison is one of the following:

• = (A equals B)
• != (A does not equal B)
• ~= (A contains B)
• !~= (A does not contain B)

And the value is a string contained in quotes. The following are all valid conditions:

• album ~= artist
• artist ~= "Fred"
• path !~= "boring-music/"

'Rule' conditions

These conditions take only one parameter, the name of a rule. These conditions evaluate to true if the track matches the given rule. These are best explained through an example:

rule fred {
    artist = "fred"
}
rule fredfoo {
    rule "fred"
    album = "foo"
}

The rule fredfoo would then match all tracks which have artist "fred" and album "foo".

Chaining conditions together

As I said, each rule can contain several conditions. These conditions are chained together with the boolean operations "and", "or", and "xor", for example:

• artist = "fred" or artist = "george"
• album = "foo" xor path ~= "bar/"

Putting it all together

So, now you can have rules like this, which would be impossible in MPDDP, even with the MPDSPL integration:

rule dark {
    artist = "Nox Arcana" or \
    artist = "Mortiis"
    album != "Grimm Tales"
    title !~= "Child"
}

A rule to return all tracks by Nox Arcana and Mortiis which do not contain "Child" in the title and are not in the album Grimm Tales.

Configuration Continued

So, what other than the rules and a bit of syntax is different for configuration? Well, MPDDP 2 can't save the playlist, or clear the playlist when it starts, any more. I never used those features, so I removed them, and MPDDP 2 now supports password-protected MPD servers! Also, as I'm sure you noticed, the "=" is gone. I might add that back…

So, here are all the configuration options for MPDDP 2:

• host
• port
• password
• changeafter
• playlistlen
• update
• active

The "active" option is a little special, it's a comma-delimited list of rules which should be used. This lets you specify many rules and, without commenting hundreds of lines out, indicate that only one or two of them should be used.

MPDDP 2 does have command-line parameters, which take priotity over the values in the config file, but I'm sure you can figure those out for yourself from the help text.

Arch Hurd has hit a big milestone, it can be booted! We can all bask in microkernally, if not particularly Archy yet, goodness. Now we need to improve our bootable environment (it has no config files, /dev is empty, et cetera) and start work on a toolchain, autotools, pacman, and all the other things we need to build packages. Currently, it's a pretty useless system—but not for long :)

Building

Firstly we need to build Arch Hurd with Allan's crosshurd scripts:

mkdir hurd
wget http://repo.archhurd.org/crosshurd/crosshurd-20100116.tar.gz
tar xvf crosshurd-20100116.tar.gz

# You might need to edit ./scripts/prepare first.

source ./scripts/makeall

mkdir $HURD_DIR/servers
touch $HURD_DIR/servers/exec
mkdir $HURD_DIR/servers/socket

mkdir $HURD_DIR/tmp
chmod 1777 $HURD_DIR/tmp

Now you can either install to a partition or to a virtual hard disk for use with a virtualisation program such as qemu. GNU Mach doesn't support SATA drives yet, so I opted for qemu:

# Create the image
qemu-img create -f raw hurd.img 1GB

# Make and format partition
losetup /dev/loop0 hurd.img
fdisk /dev/loop0
losetup -d /dev/loop0
# partition should start at sector 63. Check with fdist -ul hurd.img
losetup -o 32256 /dev/loop0 hurd.img
mkfs.ext2 -b 4096 -I 128 -o hurd -F /dev/loop0

# mount image
mkdir $ROOT/mnt
mount -o loop /dev/loop0 /mnt

# Then, build hurd and copy to /mnt
cp -a /path/to/hurd /mnt

# Unmount
umount /mnt
losetup -d /dev/loop0

# Download a grub boot image
wget http://www.dolda2000.com/~fredrik/grub.img

# Note: Networking doesn't seem to work in qemu 0.12.1, downgrade to 0.11.1
qemu -boot a -fda grub.img -hda hurd.img -net nic,vlan=1 -net user,vlan=1

And now, you have a minimally bootable Hurd system.

After booting

I imagine one of the first things you'll notice is the complaint about the lack of /dev/console. So, let's set up some devices.

settrans -c /servers/socket/1 /hurd/pflocal
cd /dev
./MAKEDEV console null zero time hd0 hd0s1

And, you have no config files. Let's start to create those:

echo "/dev/hd0s1 / ext2 defaults 1 1" > /etc/fstab
echo "root:x:0:0:root:/root:/bin/bash" > /etc/passwd

If you opted for qemu, we can also set up the network at this point:

settrans -afgp /servers/socket/2 /hurd/pfinet -i eth0 -a 10.0.2.15 -g 10.0.2.2 -m 255.255.255.0
echo "nameserver 10.0.2.3" > /etc/resolv.conf

Extra Software

I have started writing build scripts for extra software, so first set the appropriate *_VER= lines in your ./scripts/prepare file:

SED_VER=4.2.1
NCURSES_VER=5.7
NANO_VER=2.2.1

sed

#!/bin/bash

cd $SOURCE_DIR
if [ ! -f sed-$SED_VER.tar.bz2 ]; then
  wget ftp://ftp.gnu.org/gnu/sed/sed-$SED_VER.tar.bz2
fi

cd $BUILD_DIR
rm -rf sed-$SED_VER
tar -xf $SOURCE_DIR/sed-$SED_VER.tar.bz2

rm -rf sed-build
mkdir -p sed-build
cd sed-build

../sed-$SED_VER/configure \
  --host=$TARGET \
  --prefix=/usr
make DESTDIR=$HURD_DIR install

cd $ROOT

ncurses

#!/bin/bash

cd $SOURCE_DIR
if [ ! -f ncurses-$NCURSES_VER.tar.gz ]; then
  wget ftp://ftp.gnu.org/pub/gnu/ncurses/ncurses-$NCURSES_VER.tar.gz
fi

cd $BUILD_DIR
rm -rf ncurses-$NCURSES_VER
tar -xf $SOURCE_DIR/ncurses-$NCURSES_VER.tar.gz

rm -rf ncurses-build
mkdir -p ncurses-build
cd ncurses-build

../ncurses-$NCURSES_VER/configure \
  --host=$TARGET \
  --prefix=/usr \
  --mandir=/usr/share/man
  --with-shared \
  --with-normal \
  --without-debug \
  --without-ada \
  --enable-widec

make
make DESTDIR=$HURD_DIR install

cd $ROOT

nano

#!/bin/bash

cd $SOURCE_DIR
if [ ! -f nano-$NANO_VER.tar.gz ]; then
  wget http://www.nano-editor.org/dist/v2.2/nano-$NANO_VER.tar.gz
fi

cd $BUILD_DIR
rm -rf nano-$NANO_VER
tar -xf $SOURCE_DIR/nano-$NANO_VER.tar.gz

rm -rf nano-build
mkdir -p nano-build
cd nano-build

../nano-$NANO_VER/configure \
  --host=$TARGET \
  --prefix=/usr \
  --sysconfdir=/etc \
  --enable-color \
  --enable-nanorc \
  --enable-multibuffer \
  --disable-wrapping-as-root

make
make DESTDIR=$HURD_DIR install

cd $ROOT