Tweaks to allow qubes install w/o custom script

usb-boot automatically uses internal xen binary / command line
when multiboot is detected.

also tweaked to evaluate/remove variable refs in kexec arguments

initrd/bin/usb-boot

@@ -33,6 +33,7 @@ adjust_cmd_line() {
 	fi
 }
 
+first_module=y
 while read line
 do
 	key=`echo $line | cut -d\  -f1`
@@ -40,16 +41,23 @@ do
 	restval=`echo $line | cut -d\  -f3-`
 	if [ "$key" = "kernel" ]; then
 		fix_file_path
-		kexeccmd="$kexeccmd -l $filepath"
 		if [ "$kexectype" = "multiboot" ]; then
-			cmdline="$restval"
-			adjust_cmd_line
-			kexeccmd="$kexeccmd --command-line \"$cmdline\""
+			# always overload xen and with custom arguments
+			# TODO: control this replacement via flag
+			kexeccmd="$kexeccmd -l /bin/xen.gz"
+			kexeccmd="$kexeccmd --command-line \"no-real-mode reboot=no\""
+		else
+			kexeccmd="$kexeccmd -l $filepath"
 		fi
 	fi
 	if [ "$key" = "module" ]; then
 		fix_file_path
-		kexeccmd="$kexeccmd --module \"$filepath $restval\""
+		cmdline="$restval"
+		if [ -n $first_module ]; then
+			adjust_cmd_line
+			unset first_module
+		fi
+		kexeccmd="$kexeccmd --module \"$filepath $cmdline\""
 	fi
 	if [ "$key" = "initrd" ]; then
 		fix_file_path

initrd/bin/usb-parse-boot

@@ -15,14 +15,16 @@ echo_entry() {
 	if [ "$kexectype" = "elf" ]; then
 		if [ -z "$kernel" ]; then return; fi
 
-		entry="$name|$kexectype|kernel $kernel|initrd $initrd"
+		entry="$name|$kexectype|kernel $kernel"
+		if [ -n "$initrd" ]; then entry="$entry|initrd $initrd"; fi
 		if [ -n "$append" ]; then entry="$entry|append $append"; fi
-		echo "$entry"
+
+		echo $(eval "echo \"$entry\"")
 	fi
 	if [ "$kexectype" = "multiboot" ]; then
 		if [ -z "$kernel" ]; then return; fi
 
-		echo "$name|$kexectype|kernel $kernel$modules"
+		echo $(eval "echo \"$name|$kexectype|kernel $kernel$modules\"")
 	fi
 }