ARM—2410中止操控LED裸机程序

读者留意：>>后边跟的是文件名，下面是代码，程序分为几个文件！！文件运用2410开发板调试，如换其他开发板需做部分修正！

>>一/汇编部分head.S
@******************************************************************************
@ File：head.S
@ 功用：初始化，设置间断形式、管理形式的栈，设置好间断处理函数
@******************************************************************************

.extern main
.text
.global _start
_start:
@******************************************************************************
@ 间断向量，本程序中，除Reset和HandleIRQ外，其它反常都没有运用
@******************************************************************************
b Reset

@ 0x04: 未定义指令间断形式的向量地址
HandleUndef:
b HandleUndef

@ 0x08: 管理形式的向量地址，经过SWI指令进入此形式
HandleSWI:
b HandleSWI

@ 0x0c: 指令预取停止导致的反常的向量地址
HandlePrefetchAbort:
b HandlePrefetchAbort

@ 0x10: 数据拜访停止导致的反常的向量地址
HandleDataAbort:
b HandleDataAbort

@ 0x14: 保存
HandleNotUsed:
b HandleNotUsed

@ 0x18: 间断形式的向量地址
b HandleIRQ

@ 0x1c: 快间断形式的向量地址
HandleFIQ:
b HandleFIQ

Reset:
ldr sp, =4096 @ 设置栈指针，以下都是C函数，调用前需求设好栈
bl disable_watch_dog @ 封闭WATCHDOG，不然CPU会不断重启

msr cpsr_c, #0xd2 @ 进入间断形式
ldr sp, =3072 @ 设置间断形式栈指针

msr cpsr_c, #0xd3 @ 进入管理形式
ldr sp, =4096 @ 设置管理形式栈指针，
@ 其实复位之后，CPU就处于管理形式，
@ 前面的“ldr sp, =4096”完结相同的功用，此句可省掉

bl init_led @ 初始化LED的GPIO管脚
bl init_irq @ 调用间断初始化函数，在init.c中
msr cpsr_c, #0x5f @ 设置I-bit=0，开IRQ间断

ldr lr, =halt_loop @ 设置回来地址
ldr pc, =main @ 调用main函数
halt_loop:
b halt_loop

HandleIRQ:
sub lr, lr, #4 @ 核算回来地址
stmdb sp!, { r0-r12,lr } @ 保存运用到的寄存器
@ 留意，此刻的sp是间断形式的sp
@ 初始值是上面设置的3072

ldr lr, =int_return @ 设置调用ISR即EINT_Handle函数后的回来地址
ldr pc, =EINT_Handle @ 调用间断服务函数，在interrupt.c中
int_return:
ldmia sp!, { r0-r12,pc }^ @ 间断回来, ^表明将spsr的值复制到cpsr

>>main.c
int main()
{
while(1);
return 0;
}

>>init.c
/*
* init.c: 进行一些初始化
*/

#include “s3c24xx.h”

/*
* LED0,LED1,LED2对应GPc4、GPC5、GPC6
*/

#define GPC5_mask (3<<(5*2))
#define GPC6_mask (3<<(6*2))
#define GPC7_mask (3<<(7*2)) #define GPC5_out (1<<(5*2))
#define GPC6_out (1<<(6*2))
#define GPC7_out (1<<(7*2))
/*
* KEY0对应GPF5
*/
#define GPF5_eint (0x2<<(5*2))
#define GPF5_mask (3<<(5*2)) /*
* 封闭WATCHDOG，不然CPU会不断重启
*/
void disable_watch_dog(void)
{
WTCON = 0; // 封闭WATCHDOG很简单，往这个寄存器写0即可
}

void init_led(void)
{
// LED0,LED1,LED2对应的3根引脚设为输出
GPCCON &= ~(GPC5_mask | GPC6_mask | GPC7_mask);
GPCCON |= GPC5_out | GPC6_out | GPC7_out;
GPCDAT |= (0x7<<5); // 一切LED平息
}

/*
* 初始化GPIO引脚为外部间断
* GPIO引脚用作外部间断时，默以为低电平触发、IRQ方法(不必设置INTMOD)
*/
void init_irq( )
{
// key0对应的引脚设为间断引脚 EINT5
GPFCON &= ~GPF5_mask;
GPFCON |= GPF5_eint;

// 关于EINT5，需求在EINTMASK寄存器中使能它
EINTMASK &= ~(1<<5); /*
* 设定优先级：
* ARB_SEL0 = 00b, ARB_MODE0 = 0: REQ1 > REQ3，即EINT0 > EINT2
* 裁定器1、6无需设置
* 终究：
* EINT0 > EINT2 > EINT11即K2 > K3 > K4
*/
//PRIORITY = (PRIORITY & ((~0x01) | (0x3<<7))) | (0x0 << 7) ; // EINT0、EINT2、EINT8_23使能
INTMSK &= ~(1<<4);
}

>>interrupt.c
#include “s3c24xx.h”
static void delay(int n);

void EINT_Handle()
{
unsigned long oft = INTOFFSET;

switch( oft )
{
// key0被按下
case 4:
{
GPCDAT &= ~(1<<5); // LED0点亮
delay(300000);
GPCDAT |= (0x7<<5); // 一切LED平息
break;
}
default:
break;
}

//清间断
if( oft == 4 )
EINTPEND = (1<<5); // EINT4_7合用IRQ4
SRCPND = 1< INTPND = 1<}

static void delay(int n)
{
int i = 0;
for(i = 0; i}

>>Makefile（留意makefile编写时分指令前面是一个制表符Table）
objs := head.o init.o interrupt.o main.o

int.bin: $(objs)
arm-linux-ld -Ttext 0x00000000 -o int_elf $^
arm-linux-objcopy -O binary -S int_elf $@
arm-linux-objdump -D -m arm int_elf > int.dis

%.o:%.c
arm-linux-gcc -Wall -O2 -c -o $@ $< %.o:%.S
arm-linux-gcc -Wall -O2 -c -o $@ $< clean:
rm -f int.bin int_elf int.dis *.o

>>s3c24xx.h
/* WOTCH DOG register */
#define WTCON (*(volatile unsigned long *)0x53000000)

/* SDRAM regisers */
#define MEM_CTL_BASE 0x48000000
#define SDRAM_BASE 0x30000000

/* NAND Flash registers */
#define NFCONF (*(volatile unsigned int *)0x4e000000)
#define NFCMD (*(volatile unsigned char *)0x4e000004)
#define NFADDR (*(volatile unsigned char *)0x4e000008)
#define NFDATA (*(volatile unsigned char *)0x4e00000c)
#define NFSTAT (*(volatile unsigned char *)0x4e000010)

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

#define GPCCON (*(volatile unsigned long *)0x56000020)
#define GPCDAT (*(volatile unsigned long *)0x56000024)

#define GPFCON (*(volatile unsigned long *)0x56000050)
#define GPFDAT (*(volatile unsigned long *)0x56000054)
#define GPFUP (*(volatile unsigned long *)0x56000058)

#define GPGCON (*(volatile unsigned long *)0x56000060)
#define GPGDAT (*(volatile unsigned long *)0x56000064)
#define GPGUP (*(volatile unsigned long *)0x56000068)

#define GPHCON (*(volatile unsigned long *)0x56000070)
#define GPHDAT (*(volatile unsigned long *)0x56000074)
#define GPHUP (*(volatile unsigned long *)0x56000078)

/*UART registers*/
#define ULCON0 (*(volatile unsigned long *)0x50000000)
#define UCON0 (*(volatile unsigned long *)0x50000004)
#define UFCON0 (*(volatile unsigned long *)0x50000008)
#define UMCON0 (*(volatile unsigned long *)0x5000000c)
#define UTRSTAT0 (*(volatile unsigned long *)0x50000010)
#define UTXH0 (*(volatile unsigned char *)0x50000020)
#define URXH0 (*(volatile unsigned char *)0x50000024)
#define UBRDIV0 (*(volatile unsigned long *)0x50000028)

/*interrupt registes*/
#define SRCPND (*(volatile unsigned long *)0x4A000000)
#define INTMOD (*(volatile unsigned long *)0x4A000004)
#define INTMSK (*(volatile unsigned long *)0x4A000008)
#define PRIORITY (*(volatile unsigned long *)0x4A00000c)
#define INTPND (*(volatile unsigned long *)0x4A000010)
#define INTOFFSET (*(volatile unsigned long *)0x4A000014)
#define SUBSRCPND (*(volatile unsigned long *)0x4A000018)
#define INTSUBMSK (*(volatile unsigned long *)0x4A00001c)

/*external interrupt registers*/
#define EINTMASK (*(volatile unsigned long *)0x560000a4)
#define EINTPEND (*(volatile unsigned long *)0x560000a8)