如何使用clang为arduino正确编译C代码。(超时问题)

我正在尝试为atmega328p编译一些简单的裸机C代码。我正在使用arduino网络上传器进行上传 https://github.com/dbuezas/arduino-web-uploader/tree/master

这是c代码

// This blinks an led
int main() {
        *((volatile unsigned char*)0x24) = 0xFF;
        while (1) {
                *((volatile unsigned char*)0x25) = 0x00;
                for (unsigned int i1 = 0;i1 < 65535;i1++)
                for (unsigned int i2 = 0;i2 < 65535;i2++)
                for (unsigned int i3 = 0;i3 < 65535;i3++)
                for (unsigned int i4 = 0;i4 < 65535;i4++)
                        asm volatile("nop");
                *((volatile unsigned char*)0x25) = 0xFF;
                for (unsigned int i1 = 0;i1 < 65535;i1++)
                for (unsigned int i2 = 0;i2 < 65535;i2++)
                for (unsigned int i3 = 0;i3 < 65535;i3++)
                for (unsigned int i4 = 0;i4 < 65535;i4++)
                        asm volatile("nop");
        }
}

问题是我弄错了 Error: Sending 6400004620: receiveData timeout after 400ms 我已经用一些示例.hex文件测试了它,它似乎可以工作,但每当我自己编译时,我都会收到他的错误。所以我的Makefile一定有错误

# The microcontroller
MCU := atmega328p
# The clock speed in Hz.
CLOCK := 16000000

CC  := clang
LLC := llc
MC  := llvm-mc

CFLAGS := -O -nostdlib -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -flto --target=avr -mmcu=$(MCU) -DF_CPU=$(CLOCK) -DARDUINO=10607 -DARDUINO_AVR_UNO -DARDUINO_ARCH_AVR

LLCFLAGS := -march=avr -mcpu=$(MCU)

MCFLAGS := -arch=avr -mcpu=$(MCU)

C_SOURCES := $(shell find -name "*.c")

GENERATED_FILES :=

# if there are C sources, use them, otherwise search for IR files
ifneq "$(strip $(C_SOURCES))" ""
IR_FILES := $(patsubst %.c,%.ll,$(C_SOURCES))
GENERATED_FILES += $(IR_FILES)
else
IR_FILES := $(shell find -name "*.ll")
endif

# if there are IR files, use them, otherwise search of asm files
ifneq "$(strip $(IR_FILES))" ""
ASM_FILES := $(patsubst %.ll,%.s,$(IR_FILES))
GENERATED_FILES += $(ASM_FILES)
else
ASM_FILES := $(shell find -name "*.s")
endif

# if there are asm files, use them, otherwise search for obj files
# NOTE: we do not handle object files right now because the asm parser has a few bugs
ifneq "$(strip $(ASM_FILES))" ""
OBJ_FILES := $(patsubst %.s,%.o,$(ASM_FILES))
GENERATED_FILES += $(OBJ_FILES)
else
#OBJ_FILES := $(shell find -name "*.o")
endif

all: $(IR_FILES) $(ASM_FILES) $(OBJ_FILES) main.hex

rebuild: clean all

clean:
        rm -rf $(GENERATED_FILES)

%.ll: %.c
        $(CC) -c -S -emit-llvm $(CFLAGS) $< -o $@

%.s: %.ll
        $(LLC) -filetype=asm $(LLCFLAGS) $< -o $@

%.o: %.s
        $(MC) -filetype=obj $(MCFLAGS) $< -o $@

%.hex: $(OBJ_FILES)
        llvm-objcopy -O ihex $< $@ -B avr

它产生了一个main.hex,但上传似乎不起作用,顺便说一句,这里是.hex文件

:100000008FEF84B920E030E015B8F901AF01F901B4
:10001000BF01F901D90100001196AF3FB80701F403
:100020003196EF3FF80701F4FB013196EF3FF807F7
:1000300001F4FA013196EF3FF80701F485B9F901AF
:10004000AF01F901BF01F901D90100001196AF3FDD
:10005000B80701F43196EF3FF80701F4FB01319640
:10006000EF3FF80701F4FA013196EF3FF80701F48A
:0200700000C0CE
:00000001FF

我在makefile中做错了什么?