run: modularize run tool

tool/run/qemu.inc

@@ -0,0 +1,33 @@
+set qemu_spawn_id    ""
+set qemu_args        [get_cmd_arg --qemu-args ""]
+
+
+#
+# Enable run scripts to extend 'qemu_arg' via 'append' without bothering
+# about the required whitespace in front of the custom arguments.
+#
+append qemu_args " "
+
+
+proc qemu_args { } {
+	global qemu_args
+	return $qemu_args
+}
+
+
+##
+# Check whether Qemu support is available
+#
+# XXX should by removed in favor of [have_include "exec/qemu"]
+#
+proc is_qemu_available { } {
+	if {[have_spec linux]} { return false }
+
+	if {[have_spec platform_panda]
+	 || [have_spec platform_arndale]
+	 || [have_spec platform_rpi]} {
+		puts stderr "skipping execution because platform is not supported by qemu"
+		return false
+	}
+	return true
+}