Adding initial menu for hypervisors

Also testing out initial support for XenServer via ISO boot

src/hypervisors.ipxe

@@ -0,0 +1,36 @@
+#!ipxe
+
+goto ${menu} ||
+
+:hypervisors_menu
+
+menu Hypervisors
+iseq ${arch} x86_64 && set arch_a amd64 || set arch_a ${arch}
+
+item --gap Citrix XenServer
+item xs-creedence ${space} XenServer 6.5 (Creedence) [ISO]
+item xs-dundee ${space} XenServer 6.6 Beta (Dundee) [ISO]
+
+choose menu || goto hypervisors_exit
+echo ${cls}
+goto ${menu} ||
+chain ${menu}.ipxe || goto error
+goto hypervisors_exit
+
+:hypervisors_exit
+clear menu
+chain menu.ipxe
+
+:xs-creedence
+set iso http://downloadns.citrix.com.edgesuite.net/10175/XenServer-6.5.0-xenserver.org-install-cd.iso
+goto boot_iso
+
+:xs-dundee
+set iso http://downloadns.citrix.com.edgesuite.net/10759/XenServer-6.6.90-install-cd.iso
+goto boot_iso
+
+:boot_iso
+kernel ${memdisk} iso raw
+initrd ${iso}
+boot
+goto hypervisors_menu

src/menu.ipxe

@@ -30,7 +30,7 @@ item local ${space} Boot from local hdd
 item --gap Operating Systems:
 item linux ${space} Linux Operating Systems
 item bsd ${space} BSD Operating Systems
-
+item hypervisors ${space} Hypervisors
 item --gap Tools:
 item utils ${space} Utilities
 item shell ${space} iPXE shell
@@ -96,6 +96,10 @@ goto main_menu
 chain bsd.ipxe
 goto main_menu
 
+:hypervisors
+chain hypervisors.ipxe
+goto main_menu
+
 :utils
 chain utils.ipxe
 goto main_menu