[archiso] Add nbd hook, to make posible boot archiso from PXE via a NBD.

nbd (network block device utilities) package is required. This package is in AUR
at this moment: http://aur.archlinux.org/packages.php?ID=9691
Also mkinitcpio-nfs-utils is required for ipconfig.

Signed-off-by: Gerardo Exequiel Pozzi <vmlinuz386@yahoo.com.ar>

archiso/Makefile

@@ -8,6 +8,8 @@ install: all
 	# hooks/install are needed by mkinitcpio
 	install -D -m 644 hooks/archiso $(DESTDIR)/lib/initcpio/hooks/archiso
 	install -D -m 644 install/archiso $(DESTDIR)/lib/initcpio/install/archiso
+	install -D -m 644 hooks/nbd $(DESTDIR)/lib/initcpio/hooks/nbd
+	install -D -m 644 install/nbd $(DESTDIR)/lib/initcpio/install/nbd
 	# install docs and examples
 	install -d -m 644 $(DESTDIR)/usr/share/archiso/
 	cp -r ../configs $(DESTDIR)/usr/share/archiso/configs
@@ -18,5 +20,7 @@ uninstall:
 	rm -f $(DESTDIR)/usr/bin/testiso
 	rm -f $(DESTDIR)/lib/initcpio/hooks/archiso
 	rm -f $(DESTDIR)/lib/initcpio/install/archiso
+	rm -f $(DESTDIR)/lib/initcpio/hooks/nbd
+	rm -f $(DESTDIR)/lib/initcpio/install/nbd
 	rm -rf $(DESTDIR)/usr/share/archiso/
 	rm -rf $(DESTDIR)/usr/share/doc/archiso/

archiso/hooks/nbd

@@ -0,0 +1,63 @@
+# vim: set ft=sh:
+run_hook ()
+{
+    local line i address netmask gateway dns0 dns1 rootserver rootpath filename
+
+    : > /ip_opts
+
+    if [ -n "${ip}" ]; then
+        # setup network and save some values
+        ipconfig "ip=${ip}" | while read line; do
+            # echo ":: ${line}"
+            if [ "${line#"IP-Config:"}" != "${line}" ]; then
+                continue
+            fi
+            line="$(echo ${line} | sed -e 's/ :/:/g;s/: /=/g')"
+            for i in ${line}; do
+                case "${i}" in
+                    address=*)
+                        echo "${i}" >> /ip_opts
+                        ;;
+                    netmask=*)
+                        echo "${i}" >> /ip_opts
+                        ;;
+                    gateway=*)
+                        echo "${i}" >> /ip_opts
+                        ;;
+                    dns0=*)
+                        echo "${i}" >> /ip_opts
+                        ;;
+                    dns1=*)
+                        echo "${i}" >> /ip_opts
+                        ;;
+                    rootserver=*)
+                        echo "${i}" >> /ip_opts
+                        ;;
+                    rootpath=*)
+                        echo "${i}" >> /ip_opts
+                        ;;
+                esac
+            done
+        done
+
+        . /ip_opts
+
+        echo "IP-Config: ${address}/${netmask}"
+        echo "IP-Config: gw: ${gateway}    dns0: ${dns0}    dns1: ${dns1}"
+
+        modprobe nbd 2> /dev/null
+
+        msg ":: Waiting for boot device..."
+        while ! poll_device /dev/nbd0 10; do
+            echo "ERROR: boot device didn't show up after 10 seconds..."
+            echo "   Falling back to interactive prompt"
+            echo "   You can try to fix the problem manually, log out when you are finished"
+            launch_interactive_shell
+        done
+
+        msg "::: Setup NBD from ${rootserver}:9040 at /dev/nbd0 ..."
+        nbd-client ${rootserver} 9040 /dev/nbd0 -persist
+
+        archisodevice=/dev/nbd0
+    fi
+}

archiso/install/nbd

@@ -0,0 +1,20 @@
+# vim: set ft=sh:
+
+install ()
+{
+    MODULES="nbd $(checked_modules "/drivers/net/") "
+
+    BINARIES=""
+    FILES=""
+    SCRIPT="nbd"
+
+    add_binary "/usr/sbin/nbd-client" "/bin/nbd-client"
+    add_binary "/lib/initcpio/ipconfig" "/bin/ipconfig"
+}
+
+help ()
+{
+cat<<HELPEOF
+  This hook loads the necessary modules for boot via PXE and NBD.
+HELPEOF
+}