Index: Common.mk
--- Common.mk.orig
+++ Common.mk
@@ -14,7 +14,7 @@ runscript_if_exists =                                 
 
 # For message printing: pad the right side of the first argument with spaces to
 # the number of bytes indicated by the second argument.
-space_pad_to = $(shell echo $(1) "                                                      " | head -c$(2))
+space_pad_to = $(shell echo $(1) "                                                      " | dd bs=1 count=$(2) status=none)
 
 # Call with some text, and a prefix tag if desired (like [AUTODETECTED]),
 show_config_info = $(call arduino_output,- $(call space_pad_to,$(2),20) $(1))
@@ -41,6 +41,21 @@ else
     endif
     ifeq ($(UNAME_S),Darwin)
         CURRENT_OS = MAC
+    endif
+    ifeq ($(UNAME_S),OpenBSD)
+        CURRENT_OS = OPENBSD
+        ifndef ARDUINO_DIR
+            ARDUINO_DIR = ${LOCALBASE}/share/arduino
+        endif
+        ifndef ALTERNATE_CORE_PATH
+            ALTERNATE_CORE_PATH = $(ARDUINO_DIR)
+        endif
+        ifndef MONITOR_PORT
+            MONITOR_PORT = /dev/ttyU0
+        endif
+        ifeq ($(AVR_TOOLS_DIR),)
+            AVR_TOOLS_DIR = ${LOCALBASE}
+        endif
     endif
 endif
 $(call show_config_variable,CURRENT_OS,[AUTODETECTED])