Implement boot parameter "netkeys"

This allows the keys to be loaded from the boot medium even when the
root filesystem is loaded over the network.  I.e., specifying nbdroot=
no longer implies that the keys will be loaded over the network.

The ISO images generated by xorriso-usb.sh will not specify 'netkeys' so
the keys on the USB stick will be used.

The idea is that after install, the network should not be needed at
all; but that requires using a new mechanism instead of the nbdroot=
parameter, to determine dynamically whether to use a network root fs
device.

Currently, the network is still needed to boot a device that has its
root fs on the local disk and the keys on the boot medium, even though
no data is fetched from the NBD server.

You can force the machine to boot by going to the initramfs shell and
running:

  for n in $(seq 1 20); do killall ipconfig; done

Otherwise it blocks waiting for the network.

1 files changed, 20 insertions, 5 deletions

diff --git a/src/qemu.sh b/src/qemu.sh
index f9982c4..b095eb8 100755
--- a/src/qemu.sh
+++ b/src/qemu.sh
@@ -21,17 +21,32 @@ NET='tap,vlan=0,ifname=tap0,script=no,downscript=no'
 
 initrd=${samizdat_isolinux_dir}/linux/initrd.img
 kernel=${samizdat_isolinux_dir}/linux/vmlinuz
-kcmdline_NET='boot=samizdat components quiet splash nbdroot=192.168.10.1,samizdat.btrfs nbddev=/dev/nbd0 ip=dhcp'
+      kcmdline_NET='boot=samizdat components quiet splash nbdroot=192.168.10.1,samizdat.btrfs nbddev=/dev/nbd0 ip=dhcp netkeys'
+kcmdline_CDROM_NET='boot=samizdat components quiet splash nbdroot=192.168.10.1,samizdat.btrfs nbddev=/dev/nbd0 ip=dhcp'
 kcmdline_CDROM='boot=samizdat components quiet splash'
 
+set --
 if [ "$USE_ISO" ]; then
-    [ "$QEMU_LOADS_LINUX" ] && set -- -initrd "$initrd" -kernel "$kernel" -append "$kcmdline_CDROM"
-    set -- -cdrom "$iso"
+    set -- "$@" -cdrom "$iso"
+    if [ "$QEMU_LOADS_LINUX" ]; then
+        set -- "$@" -initrd "$initrd" -kernel "$kernel"
+        if [ "$NO_NET" ]; then
+            set -- "$@" -append "$kcmdline_CDROM"
+        else
+            set -- "$@" -append "$kcmdline_CDROM_NET"
+        fi
+    else
+        set -- "$@" -boot d
+    fi
 else
-    [ "$QEMU_LOADS_LINUX" ] && set -- -initrd "$initrd" -kernel "$kernel" -append "$kcmdline_NET"
-    set -- -boot n
+    if [ "$QEMU_LOADS_LINUX" ]; then
+        set -- "$@" -initrd "$initrd" -kernel "$kernel" -append "$kcmdline_NET"
+    else
+        set -- "$@" -boot n
+    fi
 fi
 
+set -x
 sudo qemu-system-x86_64 -enable-kvm -smp 2 -m 640 -k en-us \
      -vga qxl \
      -net nic,vlan=0,model=virtio \