Support emulation on GNU/Linux.

rules.mk

@@ -10,7 +10,11 @@ ifneq ($(USE_SYS),)
 CSRC += $(CHOPSTX)/mcu/sys-$(CHIP).c
 endif
 ifneq ($(USE_USB),)
+ifeq ($(EMULATION),)
 CSRC += $(CHOPSTX)/mcu/usb-$(CHIP).c
+else
+CSRC += $(CHOPSTX)/mcu/usb-usbip.c
+endif
 endif
 ifneq ($(USE_ADC),)
 CSRC += $(CHOPSTX)/contrib/adc-$(CHIP).c
@@ -19,10 +23,14 @@ endif
 INCDIR += $(CHOPSTX)
 
 BUILDDIR = build
+ifeq ($(EMULATION),)
 OUTFILES = $(BUILDDIR)/$(PROJECT).elf $(BUILDDIR)/$(PROJECT).bin
 ifneq ($(ENABLE_OUTPUT_HEX),)
 OUTFILES += $(BUILDDIR)/$(PROJECT).hex
 endif
+else
+OUTFILES  = $(BUILDDIR)/$(PROJECT)
+endif
 
 
 OPT += -ffunction-sections -fdata-sections -fno-common
@@ -34,14 +42,23 @@ LLIBDIR   = $(patsubst %,-L%,$(LIBDIR))
 
 VPATH     = $(sort $(dir $(CSRC)))
 ###
+ifeq ($(EMULATION),)
 MCFLAGS   = -mcpu=$(MCU)
+LDFLAGS   = $(MCFLAGS) -nostartfiles -T$(LDSCRIPT) \
+            -Wl,-Map=$(BUILDDIR)/$(PROJECT).map,--cref,--no-warn-mismatch,--gc-sections
+else
+MCFLAGS   =
+LDFLAGS   =
+DEFS      += -D_GNU_SOURCE
+endif
 
 CFLAGS    = $(MCFLAGS) $(OPT) $(CWARN) -Wa,-alms=$(BUILDDIR)/$(notdir $(<:.c=.lst)) $(DEFS)
+LDFLAGS  += $(LLIBDIR)
 
-LDFLAGS = $(MCFLAGS) -nostartfiles -T$(LDSCRIPT) -Wl,-Map=$(BUILDDIR)/$(PROJECT).map,--cref,--no-warn-mismatch,--gc-sections $(LLIBDIR)
-
+ifeq ($(EMULATION),)
 CFLAGS   += -mthumb -mno-thumb-interwork -DTHUMB
 LDFLAGS  += -mthumb -mno-thumb-interwork
+endif
 
 CFLAGS   += -MD -MP -MF .dep/$(@F).d
 
@@ -56,6 +73,7 @@ $(OBJS) : $(BUILDDIR)/%.o : %.c Makefile
 	@echo
 	$(CC) -c $(CFLAGS) -I. $(IINCDIR) $< -o $@
 
+ifeq ($(EMULATION),)
 %.elf: $(OBJS) $(OBJS_ADD) $(LDSCRIPT)
 	@echo
 	$(LD) $(OBJS) $(OBJS_ADD) $(LDFLAGS) $(LIBS) -o $@
@@ -65,6 +83,11 @@ $(OBJS) : $(BUILDDIR)/%.o : %.c Makefile
 
 %.hex: %.elf $(LDSCRIPT)
 	$(OBJCOPY) -O ihex $< $@
+else
+$(BUILDDIR)/$(PROJECT): $(OBJS) $(OBJS_ADD)
+	@echo
+	$(CC) $(LDFLAGS) -o $@ $(OBJS) $(OBJS_ADD) $(LIBS)
+endif
 
 clean:
 	-rm -f -r .dep $(BUILDDIR)