Remove newlib dependency, include own stdio/string/assert
diff --git a/firmware/apps/dfu/Makefile b/firmware/apps/dfu/Makefile
index 0d19e69..141b01f 100644
--- a/firmware/apps/dfu/Makefile
+++ b/firmware/apps/dfu/Makefile
@@ -1 +1,12 @@
+
C_FILES += $(C_LIBUSB_DFU)
+
+# Trace level used for compilation
+# (can be overriden by adding TRACE_LEVEL=#number to the command-line)
+# TRACE_LEVEL_DEBUG 5
+# TRACE_LEVEL_INFO 4
+# TRACE_LEVEL_WARNING 3
+# TRACE_LEVEL_ERROR 2
+# TRACE_LEVEL_FATAL 1
+# TRACE_LEVEL_NO_TRACE 0
+TRACE_LEVEL ?= 3