diff --git a/Makefile b/Makefile
index 79e7a7f2f88..518e08cf29a 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
-include config.mk
-
 SUBDIRS = icebox icepack iceprog icemulti icepll icetime icebram
 
+include config.mk
+
 all clean install uninstall:
 	for dir in $(SUBDIRS); do \
 		$(MAKE) -C $$dir $@ || exit; \
diff --git a/config.mk b/config.mk
index d6daca6eebf..7b3b4943e45 100644
--- a/config.mk
+++ b/config.mk
@@ -6,12 +6,18 @@ PKG_CONFIG ?= pkg-config
 
 C_STD ?= c99
 CXX_STD ?= c++11
+ifeq ($(EMCC),1)
+OPT_LEVEL ?= 2
+DBG_LEVEL ?=
+else
 OPT_LEVEL ?= 0
+DBG_LEVEL ?= -ggdb
+endif
 WARN_LEVEL ?= all
 
 LDLIBS = -lm -lstdc++
-CFLAGS += -MD -O$(OPT_LEVEL) -ggdb -W$(WARN_LEVEL) -std=$(C_STD) -I$(PREFIX)/include
-CXXFLAGS += -MD -O$(OPT_LEVEL) -ggdb -W$(WARN_LEVEL) -std=$(CXX_STD) -I$(PREFIX)/include
+CFLAGS += -MD -O$(OPT_LEVEL) $(DBG_LEVEL) -W$(WARN_LEVEL) -std=$(C_STD) -I$(PREFIX)/include
+CXXFLAGS += -MD -O$(OPT_LEVEL) $(DBG_LEVEL) -W$(WARN_LEVEL) -std=$(CXX_STD) -I$(PREFIX)/include
 
 DESTDIR ?=
 CHIPDB_SUBDIR ?= icebox
@@ -22,3 +28,12 @@ CXX = /usr/local/src/mxe/usr/bin/i686-w64-mingw32.static-gcc
 CC = $(CXX)
 PKG_CONFIG = /usr/local/src/mxe/usr/bin/i686-w64-mingw32.static-pkg-config
 endif
+
+ifeq ($(EMCC),1)
+EXE = .js
+CC = emcc
+CXX = emcc
+PREFIX = /
+LDFLAGS = -O2 --memory-init-file 0 -s TOTAL_MEMORY=64*1024*1024
+SUBDIRS = icebox icepack icemulti icepll icetime icebram
+endif
diff --git a/icebram/Makefile b/icebram/Makefile
index 3904926e9c2..34801da3c9c 100644
--- a/icebram/Makefile
+++ b/icebram/Makefile
@@ -20,7 +20,7 @@ uninstall:
 	rm -f $(DESTDIR)$(PREFIX)/bin/icebram$(EXE)
 
 clean:
-	rm -f icebram
+	rm -f icebram$(EXE)
 	rm -f icebram.exe
 	rm -f demo.* demo_*.*
 	rm -f *.o *.d
diff --git a/icemulti/Makefile b/icemulti/Makefile
index 530215881c1..7e2fe1c1cf2 100644
--- a/icemulti/Makefile
+++ b/icemulti/Makefile
@@ -17,7 +17,7 @@ uninstall:
 	rm -f $(DESTDIR)$(PREFIX)/bin/icemulti$(EXE)
 
 clean:
-	rm -f icemulti
+	rm -f icemulti$(EXE)
 	rm -f icemulti.exe
 	rm -f *.o *.d
 
diff --git a/icepack/Makefile b/icepack/Makefile
index 65d4c9a5fa4..3e8c774216e 100644
--- a/icepack/Makefile
+++ b/icepack/Makefile
@@ -10,8 +10,8 @@ all: icepack$(EXE) iceunpack$(EXE)
 icepack$(EXE): icepack.o
 	$(CXX) -o $@ $(LDFLAGS) $^ $(LDLIBS)
 
-iceunpack: icepack
-	ln -sf icepack iceunpack
+iceunpack$(EXE): icepack$(EXE)
+	ln -sf icepack$(EXE) iceunpack$(EXE)
 
 iceunpack.exe:
 	# no iceunpack.exe, use icepack -u
@@ -26,8 +26,8 @@ uninstall:
 	rm -f $(DESTDIR)$(PREFIX)/bin/iceunpack$(EXE)
 
 clean:
-	rm -f icepack
-	rm -f iceunpack
+	rm -f icepack$(EXE)
+	rm -f iceunpack$(EXE)
 	rm -f icepack.exe
 	rm -f *.o *.d
 
diff --git a/icepll/Makefile b/icepll/Makefile
index 87eabfa6f63..13a1d81c586 100644
--- a/icepll/Makefile
+++ b/icepll/Makefile
@@ -17,7 +17,7 @@ uninstall:
 	rm -f $(DESTDIR)$(PREFIX)/bin/icepll$(EXE)
 
 clean:
-	rm -f icepll
+	rm -f icepll$(EXE)
 	rm -f icepll.exe
 	rm -f *.o *.d
 
diff --git a/icetime/Makefile b/icetime/Makefile
index 5e959c7a159..d0581535db8 100644
--- a/icetime/Makefile
+++ b/icetime/Makefile
@@ -8,6 +8,22 @@ endif
 
 all: icetime$(EXE)
 
+ifeq ($(EXE),.js)
+icetime$(EXE): | share/$(CHIPDB_SUBDIR)/chipdb-384.txt share/$(CHIPDB_SUBDIR)/chipdb-1k.txt share/$(CHIPDB_SUBDIR)/chipdb-8k.txt
+
+share/$(CHIPDB_SUBDIR)/chipdb-384.txt: ../icebox/chipdb-384.txt
+	mkdir -p share/$(CHIPDB_SUBDIR)
+	cp $< $@
+share/$(CHIPDB_SUBDIR)/chipdb-1k.txt: ../icebox/chipdb-1k.txt
+	mkdir -p share/$(CHIPDB_SUBDIR)
+	cp $< $@
+share/$(CHIPDB_SUBDIR)/chipdb-8k.txt: ../icebox/chipdb-8k.txt
+	mkdir -p share/$(CHIPDB_SUBDIR)
+	cp $< $@
+
+override LDFLAGS += --embed-file share
+endif
+
 icetime$(EXE): icetime.o
 	$(CXX) -o $@ $(LDFLAGS) $^ $(LDLIBS)
 
@@ -46,7 +62,7 @@ test: test0 test1 test2 test3 test4 test5 test6 test7 test8 test9
 show: show0 show1 show2 show3 show4 show5 show6 show7 show8 show9
 
 clean:
-	rm -f icetime icetime.exe timings.inc *.o *.d
+	rm -f icetime$(EXE) icetime.exe timings.inc *.o *.d
 	rm -rf test[0-9]*
 
 -include *.d