snek-duino: Use -mcall-prologues to save ROM

This un-inlines function setup/teardown and uses a function for that
(shades of the Ritchie C compiler on the PDP-11)

Signed-off-by: Keith Packard <keithp@keithp.com>

snek-duino/Makefile

@@ -30,7 +30,7 @@ ELF=$(BASE).elf
 HEX=$(BASE).hex
 MAP=$(BASE).map
 CC=avr-gcc
-CFLAGS=-Os -DF_CPU=16000000UL -mmcu=atmega328p -I. -g -fno-jump-tables $(SNEK_CFLAGS)
+CFLAGS=-Os -DF_CPU=16000000UL -mmcu=atmega328p -I. -g -fno-jump-tables $(SNEK_CFLAGS) -mcall-prologues
 LDFLAGS=-Wl,-uvfprintf -lprintf_flt -lm \
 	-Wl,--defsym -Wl,__TEXT_REGION_LENGTH__=0x8000 \
 	-Wl,--defsym -Wl,__DATA_REGION_LENGTH__=0x7a0 \
@@ -82,8 +82,8 @@ set-fuse:
 	avrdude -F -V -c $(ISP) -p ATMEGA328P -U hfuse:w:0xd7:m
 	avrdude -F -V -c $(ISP) -p ATMEGA328P -U efuse:w:0xfd:m
 
-load: $(HEX)
-	avrdude -F -V -c $(ISP) -p ATMEGA328P -U flash:w:$(HEX)
+load: $(HEX) snek-duino-install
+	./snek-duino-install -isp $(ISP) -hex $(HEX) load
 
 install: snek-duino-install $(HEX) snek-duino-install.1
 	install -d $(DESTDIR)$(BINDIR)