diff --git a/software/bios/Makefile b/software/bios/Makefile
index e96ef4469..128bc17ee 100644
--- a/software/bios/Makefile
+++ b/software/bios/Makefile
@@ -18,12 +18,11 @@ bios.elf: linker.ld $(OBJECTS) libs
 bios-rescue.elf: linker-rescue.ld $(OBJECTS) libs
 
 %.elf:
-	$(LD) $(LDFLAGS) -T $< -N -o $@ $(OBJECTS) -L$(M2DIR)/software/libbase -L$(M2DIR)/software/libextra -lbase -lextra
+	$(LD) $(LDFLAGS) -T $< -N -o $@ $(OBJECTS) -L$(M2DIR)/software/libbase -lbase
 	chmod -x $@
 
 libs:
 	make -C $(M2DIR)/software/libbase
-	make -C $(M2DIR)/software/libextra
 
 flash: bios.bin
 	m1nor bios.bin
diff --git a/software/bios/boot.c b/software/bios/boot.c
index 3ea515fdd..74b0f558f 100644
--- a/software/bios/boot.c
+++ b/software/bios/boot.c
@@ -20,7 +20,7 @@
 #include <uart.h>
 #include <system.h>
 #include <board.h>
-#include <extra/crc.h>
+#include <crc.h>
 #include <sfl.h>
 #include <string.h>
 #include <irq.h>
diff --git a/software/bios/main.c b/software/bios/main.c
index 1aeb4c654..21b6aee95 100644
--- a/software/bios/main.c
+++ b/software/bios/main.c
@@ -23,7 +23,7 @@
 #include <board.h>
 #include <irq.h>
 #include <version.h>
-#include <extra/crc.h>
+#include <crc.h>
 #include <timer.h>
 
 #include <hw/flash.h>
diff --git a/software/bios/microudp.c b/software/bios/microudp.c
index c80c60ba9..44d58a62b 100644
--- a/software/bios/microudp.c
+++ b/software/bios/microudp.c
@@ -17,7 +17,7 @@
 
 #include <stdio.h>
 #include <system.h>
-#include <extra/crc.h>
+#include <crc.h>
 #include <hw/minimac.h>
 
 #include "microudp.h"
diff --git a/software/include/extra/crc.h b/software/include/base/crc.h
similarity index 100%
rename from software/include/extra/crc.h
rename to software/include/base/crc.h
diff --git a/software/libbase/Makefile b/software/libbase/Makefile
index e3ddbfb8e..2ea9e1efa 100644
--- a/software/libbase/Makefile
+++ b/software/libbase/Makefile
@@ -1,7 +1,7 @@
 M2DIR=../..
 include $(M2DIR)/software/include.mak
 
-OBJECTS=divsi3.o libc.o console.o timer.o system.o board.o uart.o softfloat.o softfloat-glue.o vsnprintf.o atof.o
+OBJECTS=divsi3.o libc.o crc16.o crc32.o console.o timer.o system.o board.o uart.o softfloat.o softfloat-glue.o vsnprintf.o atof.o
 
 all: libbase.a
 
diff --git a/software/libextra/crc16.c b/software/libbase/crc16.c
similarity index 99%
rename from software/libextra/crc16.c
rename to software/libbase/crc16.c
index afd848c60..a1222e861 100644
--- a/software/libextra/crc16.c
+++ b/software/libbase/crc16.c
@@ -1,4 +1,4 @@
-#include <extra/crc.h>
+#include <crc.h>
 
 static const unsigned int crc16_table[256] = {
 	0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50A5, 0x60C6, 0x70E7,
diff --git a/software/libextra/crc32.c b/software/libbase/crc32.c
similarity index 99%
rename from software/libextra/crc32.c
rename to software/libbase/crc32.c
index f9438227d..29b9b9944 100644
--- a/software/libextra/crc32.c
+++ b/software/libbase/crc32.c
@@ -3,7 +3,7 @@
  * For conditions of distribution and use, see copyright notice in zlib.h
  */
 
-#include <extra/crc.h>
+#include <crc.h>
 
 static const unsigned int crc_table[256] = {
 	0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
diff --git a/software/libextra/Makefile b/software/libextra/Makefile
deleted file mode 100644
index 34747a65c..000000000
--- a/software/libextra/Makefile
+++ /dev/null
@@ -1,18 +0,0 @@
-M2DIR=../..
-include $(M2DIR)/software/include.mak
-
-OBJECTS=crc16.o crc32.o
-
-all: libextra.a
-
-# pull in dependency info for *existing* .o files
--include $(OBJECTS:.o=.d)
-
-libextra.a: $(OBJECTS)
-	$(AR) clr libextra.a $(OBJECTS)
-	$(RANLIB) libextra.a
-
-.PHONY: clean
-
-clean:
-	rm -f $(OBJECTS) $(OBJECTS:.o=.d) libextra.a .*~ *~