FrSky did introduce 2us jitter since last optimization

Makefile minor update
Google tests fixed
Momentary switches in FUNC SWITCHES screen (not finished)
Trim parameter in Mixer is OFF if the source is not a stick

src/Makefile

@@ -529,9 +529,7 @@ MSG_FLASH = Creating load file for Flash:
 MSG_EEPROM = Creating load file for EEPROM:
 MSG_EXTENDED_LISTING = Creating Extended Listing:
 MSG_SYMBOL_TABLE = Creating Symbol Table:
-MSG_LINKING = Linking:
-MSG_COMPILING = Compiling C:
-MSG_COMPILING_CPP = Compiling C++:
+MSG_COMPILING = Compiling C++:
 MSG_ASSEMBLING = Assembling:
 MSG_CLEANING = Cleaning project:
 MSG_CREATING_LIBRARY = Creating library:
@@ -539,7 +537,6 @@ MSG_CREATING_LIBRARY = Creating library:
 # Compiler flags to generate dependency files.
 GENDEPFLAGS = -MD -MP -MF .dep/$(@F).d
 
-
 # Combine all necessary flags and optional flags.
 # Add target processor to flags.
 ALL_CPPFLAGS = -mmcu=$(MCU) -I. -x c++ $(CPPFLAGS) $(GENDEPFLAGS) $(AVRGCCFLAGS) -fwhole-program
@@ -554,8 +551,7 @@ BUILD_DIR = $(shell pwd | awk -F'/' '{print $$((NF-1))}')
 all: begin gccversion sizebefore build sizeafter end
 
 # Change the build target to build a HEX file or a library.
-build: stamp_header font.lbm font_dblsize.lbm sticks.lbm s9xsplash.lbm elf hex eep lss sym
-
+build: stamp_header font.lbm font_dblsize.lbm sticks.lbm s9xsplash.lbm allsrc elf remallsrc hex eep lss sym
 
 elf: $(TARGET).elf
 hex: $(TARGET).hex
@@ -566,8 +562,6 @@ sym: $(TARGET).sym
 # Build stamp-file
 stamp_header:
 	@echo
-	@echo $(CPPSRC)
-	
 	@echo "Generate Version-stamp:"
 	@echo "//Automatically generated file (Makefile) - do not edit" > stamp-open9x.h
 	@echo "#define DATE_STR \"`date +%Y-%m-%d`\"" >> stamp-open9x.h
@@ -746,14 +740,19 @@ extcoff: $(TARGET).elf
 	@echo $(MSG_SYMBOL_TABLE) $@
 	$(NM) -n $< > $@
 
-# Link: create ELF output file from object files.
-%.elf:
-	@echo
-	@echo $(MSG_LINKING) $@
+# Concatenate all sources files in one big file to optimize size
+allsrc: $(CPPSRC)
 	cat $(CPPSRC) > allsrc.cpp
+	
+remallsrc:
+	$(REMOVE) allsrc.cpp
+    
+# Link: create ELF output file from object files.
+%.elf: allsrc
 	@echo
+	@echo $(MSG_COMPILING) $@
 	$(CC) $(ALL_CPPFLAGS) allsrc.cpp --output $@ $(LDFLAGS)
-
+	
 # Target: clean project.
 clean: begin clean_list end
 
@@ -775,6 +774,7 @@ clean_list :
 	$(REMOVE) $(SRC:.c=.s)
 	$(REMOVE) *.o
 	$(REMOVE) *.d
+	$(REMOVE) allsrc.cpp
 	$(REMOVEDIR) .dep
 
 # Include the dependency files.