dracut: Provide minimalistic initramfs files - no udev, no systemd

Provide simple script to run under busybox, this is all we need in the
VM.

dracut/Makefile

@@ -1,4 +1,3 @@
 install:
-	install -d $(DESTDIR)/usr/lib/dracut/modules.d/90qubes-vm
+	$(MAKE) -C simple
-	install module-setup.sh mount_modules.sh qubes_cow_setup.sh \
+	$(MAKE) -C full
-		$(DESTDIR)/usr/lib/dracut/modules.d/90qubes-vm/

dracut/full/Makefile

@@ -0,0 +1,4 @@
+install:
+	install -d $(DESTDIR)/usr/lib/dracut/modules.d/90qubes-vm
+	install module-setup.sh mount_modules.sh qubes_cow_setup.sh \
+		$(DESTDIR)/usr/lib/dracut/modules.d/90qubes-vm/

dracut/full/mount_modules.sh

@@ -11,3 +11,4 @@ if ! [ -d $NEWROOT/lib/modules/`uname -r` ]; then
     mount -n -t ext3 /dev/xvdd $NEWROOT/lib/modules
 fi
 
+killall udevd systemd-udevd

dracut/simple/Makefile

@@ -0,0 +1,4 @@
+install:
+	install -d $(DESTDIR)/usr/lib/dracut/modules.d/90qubes-vm-simple
+	install module-setup.sh init.sh \
+		$(DESTDIR)/usr/lib/dracut/modules.d/90qubes-vm-simple/

dracut/simple/init.sh

@@ -0,0 +1,48 @@
+#!/bin/sh
+echo "Qubes initramfs script here:"
+
+mkdir -p /proc /sys /dev
+mount -t proc proc /proc
+mount -t sysfs sysfs /sys
+mount -t devtmpfs devtmpfs /dev
+
+if [ -e /dev/mapper/dmroot ] ; then 
+    die "Qubes: FATAL error: /dev/mapper/dmroot already exists?!"
+fi
+
+modprobe xenblk || modprobe xen-blkfront || echo "Qubes: Cannot load Xen Block Frontend..."
+
+echo "Waiting for /dev/xvda* devices..."
+while ! [ -e /dev/xvda ]; do sleep 0.1; done
+
+if [ `cat /sys/block/xvda/ro` = 1 ] ; then
+	echo "Qubes: Doing COW setup for AppVM..."
+
+	while ! [ -e /dev/xvdc ]; do sleep 0.1; done
+	while ! [ -e /dev/xvdc2 ]; do sleep 0.1; done
+
+	echo "0 `cat /sys/block/xvda/size` snapshot /dev/xvda /dev/xvdc2 N 16" | \
+    		dmsetup create dmroot || { echo "Qubes: FATAL: cannot create dmroot!"; }
+	echo Qubes: done.
+else
+	echo "Qubes: Doing R/W setup for TemplateVM..."
+	echo "0 `cat /sys/block/xvda/size` linear /dev/xvda 0" | \
+    		dmsetup create dmroot || { echo "Qubes: FATAL: cannot create dmroot!"; exit 1; }
+	echo Qubes: done.
+fi
+dmsetup mknodes dmroot
+
+mkdir -p /sysroot
+mount /dev/mapper/dmroot /sysroot -o ro
+
+if ! [ -d $NEWROOT/lib/modules/`uname -r` ]; then
+    echo "Waiting for /dev/xvdd device..."
+    while ! [ -e /dev/xvdd ]; do sleep 0.1; done
+
+    mount -n -t ext3 /dev/xvdd $NEWROOT/lib/modules
+fi
+
+
+umount /dev /sys /proc
+
+exec switch_root /sysroot /sbin/init

dracut/simple/module-setup.sh

@@ -0,0 +1,14 @@
+#!/bin/bash
+
+check() {
+    return 255
+}
+
+depends() {
+    echo busybox dm
+    return 0
+}
+
+install() {
+    inst $moddir/init.sh /init
+}

kernel-modules/qubes-prepare-vm-kernel

@@ -28,7 +28,7 @@ basedir=/var/lib/qubes/vm-kernels
 function recompile_u2mfn() {
     kver=$1
     u2mfn_ver=`dkms status u2mfn|tail -n 1|cut -f 2 -d ' '|tr -d ':,'`
-    dkms install u2mfn/$u2mfn_ver -k $kver
+    dkms install u2mfn/$u2mfn_ver -k $kver --no-initrd
 }
 
 function build_modules_img() {
@@ -50,8 +50,8 @@ function build_initramfs() {
     output_file=$2
 
     /sbin/dracut --nomdadmconf --nolvmconf --force \
-        --modules "bash dm kernel-modules rootfs-block base fs-lib shutdown" \
+        --modules "kernel-modules qubes-vm-simple" \
-        --modules "qubes-vm" --conf /dev/null --confdir /var/empty \
+        --conf /dev/null --confdir /var/empty \
         -d "xenblk xen-blkfront cdrom ext4 jbd2 crc16 dm_snapshot" \
         $output_file $kver
 }

rpm_spec/qubes-kernel-vm-support.spec

@@ -34,6 +34,7 @@ URL:		http://www.qubes-os.org
 
 Requires:	dracut
 Requires:	dkms
+Requires:	busybox
 
 %define _builddir %(pwd)
 
@@ -60,6 +61,7 @@ make install-kernel-support DESTDIR=%{buildroot}
 
 %files
 /usr/lib/dracut/modules.d/90qubes-vm
+/usr/lib/dracut/modules.d/90qubes-vm-simple
 /usr/src/u2mfn-%{version}/
 /usr/sbin/qubes-prepare-vm-kernel