Led_on_c

会有3个led灯亮起

 

crt0.S

.text
.global _start
_start:
    ldr r0,=0x53000000
    mov r1,#0x0
    str r1,[r0]
    ldr sp,=1024*4
    bl main
halt_loop:
    b halt_loop

关闭看门狗，设置堆栈

led_on_c.c

#define GPBCON (*(volatile unsigned long *)0x56000010)
#define GPBDAT (*(volatile unsigned long *)0x56000014)

int main()
{
    GPBCON = 0x00005400;
    GPBDAT = 0x00000000;

    return 0;
}

 

Makefile

led_on_c.bin:crt0.S led_on_c.c
    arm-linux-gcc -g -c -o crt0.o crt0.S
    arm-linux-gcc -g -c -o led_on_c.o led_on_c.c
    arm-linux-ld -Ttext 0x00000000 -g crt0.o led_on_c.o -o led_on_c_elf
    arm-linux-objcopy -O binary -S led_on_c_elf led_on_c.bin
    arm-linux-objdump -D -m arm led_on_c_elf > led_on_c.dis
clean:
    rm -rf led_on_c.dis led_on_c.bin led_on_c_elf *.o