arm: add uart echo app

arm/makefile

@@ -4,17 +4,32 @@ CXX = arm-none-eabi-g++
 OBJCOPY = arm-none-eabi-objcopy
 
 linker_script = bootloader.ld
+includes = 
+sources =
 
-CFLAGS = -march=armv6-m -g -ffunction-sections -fdata-sections -O2
+CFLAGS = -march=armv6-m -g -ffunction-sections -fdata-sections -O2 -Werror -Wall
 CXXFLAGS = $(CFLAGS) -std=c++20 -fno-exceptions
-LDFLAGS = -march=armv6-m -g --specs=nano.specs --specs=nosys.specs -Wl,--gc-sections -Wl,-T$(linker_script) -O2
+LDFLAGS = -march=armv6-m \
+		  -g --specs=nano.specs --specs=nosys.specs \
+		  -Wl,--gc-sections -Wl,-T$(linker_script) -O2 \
+		  -Wl,--print-memory-usage
 
-all: bootloader.bin
+sources += hal/lib/common/xil_assert.c
+includes += -Ihal/lib/common
+
+sources += hal/uart/xuartlite.c hal/uart/xuartlite_stats.c
+includes += -Ihal/uart
+
+objects = main.o vector_table.o $(sources:.c=.o)
+
+CFLAGS += $(includes)
+
+all: bootloader.elf
 
 %.bin: %.elf
 	$(OBJCOPY) -O binary $< $@
 
-bootloader.elf: main.o vector_table.o
+bootloader.elf: $(objects)
 
 %.elf:
 	$(LD) $(LDFLAGS) -o $@ $^
@@ -22,4 +37,4 @@ bootloader.elf: main.o vector_table.o
 .PHONY: clean
 
 clean:
-	rm -rf *.elf *.bin *.o
+	rm -rf *.elf *.bin $(objects)