qubes-linux-utils/dracut/simple/init.sh
Marek Marczykowski-Górecki da3f3cd426
initramfs: use symlink for rw root.img, instead of dm-linear
Do not add 1:1 dm-linear when root.img (/dev/xvda) is read-write. This
was to always have root device at /dev/mapper/dmroot, but unfortunately
grub can't parse it properly (fails at looking for partition number of
/dev/xvda1). There was a hack specifically for this, but it caused other
partitions on xvda unavailable.
On the other hand, symlink is enough to be able to mount always the same
device. Now, grub detect that root fs is on /dev/xvda1, which is
enough to have grub2-install working. Unfortunate effect is that it puts
root=/dev/xvda1 at kernel command line, which breaks AppVMs based on
this TemplateVM. But it's easier to fix kernel command line, than grub
device detection logic.

Fixes "initramfs: add support for root.img with partition table"

QubesOS/qubes-issues#2557
2017-06-12 13:02:31 +02:00

99 lines
2.7 KiB
Bash

#!/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
echo "Qubes: FATAL error: /dev/mapper/dmroot already exists?!"
fi
modprobe xenblk || modprobe xen-blkfront || echo "Qubes: Cannot load Xen Block Frontend..."
die() {
echo "$@" >&2
exit 1
}
echo "Waiting for /dev/xvda* devices..."
while ! [ -e /dev/xvda ]; do sleep 0.1; done
# prefer first partition if exists
if [ -b /dev/xvda1 ]; then
ROOT_DEV=xvda1
else
ROOT_DEV=xvda
fi
SWAP_SIZE=$(( 1024 * 1024 * 2 )) # sectors, 1GB
if [ `cat /sys/class/block/$ROOT_DEV/ro` = 1 ] ; then
echo "Qubes: Doing COW setup for AppVM..."
while ! [ -e /dev/xvdc ]; do sleep 0.1; done
VOLATILE_SIZE=$(cat /sys/class/block/xvdc/size) # sectors
ROOT_SIZE=$(cat /sys/class/block/$ROOT_DEV/size) # sectors
if [ $VOLATILE_SIZE -lt $SWAP_SIZE ]; then
die "volatile.img smaller than 1GB, cannot continue"
fi
sfdisk -q --unit S /dev/xvdc >/dev/null <<EOF
1,$SWAP_SIZE,S
,,L
EOF
if [ $? -ne 0 ]; then
echo "Qubes: failed to setup partitions on volatile device"
exit 1
fi
while ! [ -e /dev/xvdc1 ]; do sleep 0.1; done
mkswap /dev/xvdc1
while ! [ -e /dev/xvdc2 ]; do sleep 0.1; done
echo "0 `cat /sys/class/block/$ROOT_DEV/size` snapshot /dev/$ROOT_DEV /dev/xvdc2 N 16" | \
dmsetup create dmroot || { echo "Qubes: FATAL: cannot create dmroot!"; exit 1; }
dmsetup mknodes dmroot
echo Qubes: done.
else
echo "Qubes: Doing R/W setup for TemplateVM..."
while ! [ -e /dev/xvdc ]; do sleep 0.1; done
sfdisk -q --unit S /dev/xvdc >/dev/null <<EOF
1,$SWAP_SIZE,S
EOF
if [ $? -ne 0 ]; then
die "Qubes: failed to setup partitions on volatile device"
fi
while ! [ -e /dev/xvdc1 ]; do sleep 0.1; done
mkswap /dev/xvdc1
ln -s ../$ROOT_DEV /dev/mapper/dmroot
echo Qubes: done.
fi
modprobe ext4
mkdir -p /sysroot
mount /dev/mapper/dmroot /sysroot -o ro
NEWROOT=/sysroot
kver="`uname -r`"
if ! [ -d "$NEWROOT/lib/modules/$kver/kernel" ]; then
echo "Waiting for /dev/xvdd device..."
while ! [ -e /dev/xvdd ]; do sleep 0.1; done
# Mount only `uname -r` subdirectory, to leave the rest of /lib/modules writable
mkdir -p /tmp/modules
mount -n -t ext3 /dev/xvdd /tmp/modules
if ! [ -d "$NEWROOT/lib/modules/$kver" ]; then
mount "$NEWROOT" -o remount,rw
mkdir -p "$NEWROOT/lib/modules/$kver"
mount "$NEWROOT" -o remount,ro
fi
mount --bind "/tmp/modules/$kver" "$NEWROOT/lib/modules/$kver"
umount /tmp/modules
rmdir /tmp/modules
fi
umount /dev /sys /proc
exec switch_root $NEWROOT /sbin/init