Fix fpga_compress race condition and isolate it in tools

tools/fpga_compress/Makefile

@@ -0,0 +1,69 @@
+# Hide full compilation line:
+ifneq ($(V),1)
+  Q?=@
+endif
+# To see full command lines, use make V=1
+
+CC = gcc
+CXX = g++
+LD = g++
+RM = rm -f
+MV = mv
+
+VPATH = ../../common/zlib
+OBJDIR = obj
+
+# RPi Zero gcc requires -latomic
+# but MacOSX /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ld
+# doesn't recognize option --as-needed
+ifneq ($(platform),Darwin)
+    LDLIBS += -Wl,--as-needed -latomic -Wl,--no-as-needed
+endif
+
+LIBS = -I../../common/zlib
+INCLUDES_CLIENT = -I../../common_fpga $(LIBS)
+
+CFLAGS += -std=c99 -D_ISOC99_SOURCE -DPRESETS $(INCLUDES_CLIENT) -Wall -Werror -g -O3
+
+# Flags to generate temporary dependency files
+DEPFLAGS = -MT $@ -MMD -MP -MF $(OBJDIR)/$*.Td
+# make temporary to final dependency files after successful compilation
+POSTCOMPILE = $(MV) -f $(OBJDIR)/$*.Td $(OBJDIR)/$*.d
+
+ZLIBSRCS = deflate.c adler32.c trees.c zutil.c inflate.c inffast.c inftrees.c
+ZLIBFLAGS = -DZ_SOLO -DZ_PREFIX -DNO_GZIP -DZLIB_PM3_TUNED
+#-DDEBUG -Dverbose=1
+
+ZLIBOBJS = $(ZLIBSRCS:%.c=$(OBJDIR)/%.o)
+
+BINS = fpga_compress
+CLEAN = $(BINS) $(DEPENDENCY_FILES) $(ZLIBOBJS) $(OBJDIR)/*.o
+
+# need to assign dependancies to build these first...
+all: $(BINS)
+
+all-static: LDLIBS:=-static $(LDLIBS)
+all-static: $(BINS)
+
+fpga_compress: $(OBJDIR)/fpga_compress.o $(ZLIBOBJS)
+	$(info [=] LD $@)
+	$(Q)$(LD) $(LDFLAGS) $(ZLIBFLAGS) $^ $(LDLIBS) -o $@
+
+clean:
+	$(Q)$(RM) $(CLEAN)
+
+.PHONY: all clean
+
+%.o: %.c
+$(OBJDIR)/%.o : %.c $(OBJDIR)/%.d
+	$(info [-] CC $<)
+	$(Q)$(CC) $(DEPFLAGS) $(CFLAGS) $(ZLIBFLAGS) -c -o $@ $<
+	$(Q)$(POSTCOMPILE)
+
+DEPENDENCY_FILES = $(patsubst %.c, $(OBJDIR)/%.d, $(ZLIBSRCS)) $(OBJDIR)/fpga_compress.d
+
+$(DEPENDENCY_FILES): ;
+.PRECIOUS: $(DEPENDENCY_FILES)
+
+-include $(DEPENDENCY_FILES)
+