硬件：JZ2440

实现功能：用putchr()函数实现printf()

start.s

nand.c

uart.c

uart.h

my_stdio.c

my_stdio.h

main.c

start.s源码：

.extern main

.text

.global _start

_start:

      ldr sp,=

      bl  watchdog_init

      bl  clock_init

      bl  nand_init

      bl  sdram_init 

      ldr r0,=0x30000000

      mov r1,#

      mov r2,#(*)

      bl  nand_read

      ldr sp,=0x34000000

      ldr lr,=main_return

      ldr pc,=main

main_return:

      b main_return

init.c

//watchdog

#define WTCON      (*(volatile unsigned long *)0x53000000)

//clock

#define LOCKTIME   (*(volatile unsigned long *)0x4c000000)

#define MPLLCON    (*(volatile unsigned long *)0x4c000004)

#define CLKDIVN    (*(volatile unsigned long *)0x4c000014)

//sdram

#define BWSCON     (*(volatile unsigned long *)0x48000000)

#define BANKCON0   (*(volatile unsigned long *)0x48000004)

#define BANKCON1   (*(volatile unsigned long *)0x48000008)

#define BANKCON2   (*(volatile unsigned long *)0x4800000c)

#define BANKCON3   (*(volatile unsigned long *)0x48000010)

#define BANKCON4   (*(volatile unsigned long *)0x48000014)

#define BANKCON5   (*(volatile unsigned long *)0x48000018)

#define BANKCON6   (*(volatile unsigned long *)0x4800001c)

#define BANKCON7   (*(volatile unsigned long *)0x48000020)

#define REFRESH    (*(volatile unsigned long *)0x48000024)

#define BANKSIZE   (*(volatile unsigned long *)0x48000028)

#define MRSRB6     (*(volatile unsigned long *)0x4800002c)

#define MRSRB7     (*(volatile unsigned long *)0x48000030)

void watchdog_init(void)

{

    WTCON=;

}

void clock_init(void)

{

    CLKDIVN=0x03;

    __asm__

    (

    "mrc p15,0,r1,c1,c0,0\n"

    "orr r1,r1,#0xc0000000\n"

    "mcr p15,0,r1,c1,c0,0\n"

    );

       MPLLCON=((0x5c<<)|(0x01<<)|(0x02));

}

void sdram_init(void)

{

    volatile unsigned long *sdram_base=(volatile unsigned long *)0x48000000;

    sdram_base[]  = 0x22011110;

    sdram_base[]  = 0x00000700;

    sdram_base[]  = 0x00000700;

    sdram_base[]  = 0x00000700;

    sdram_base[]  = 0x00000700;

    sdram_base[]  = 0x00000700;

    sdram_base[]  = 0x00000700;

    sdram_base[]  = 0x00018005;

    sdram_base[]  = 0x00018005;

    sdram_base[]  = 0x008C04F4;

    sdram_base[] = 0x000000B1;

    sdram_base[] = 0x00000030;

    sdram_base[] = 0x00000030;     

}

nand.c

#define LARGER_NAND_PAGE

#define GSTATUS1        (*(volatile unsigned int *)0x560000B0)

#define BUSY            1

#define NAND_SECTOR_SIZE    512

#define NAND_BLOCK_MASK     (NAND_SECTOR_SIZE - 1)

#define NAND_SECTOR_SIZE_LP    2048

#define NAND_BLOCK_MASK_LP     (NAND_SECTOR_SIZE_LP - 1)

typedef unsigned int S3C24X0_REG32;

/* NAND FLASH (see S3C2410 manual chapter 6) */

typedef struct {

    S3C24X0_REG32   NFCONF;

    S3C24X0_REG32   NFCMD;

    S3C24X0_REG32   NFADDR;

    S3C24X0_REG32   NFDATA;

    S3C24X0_REG32   NFSTAT;

    S3C24X0_REG32   NFECC;

} S3C2410_NAND;

/* NAND FLASH (see S3C2440 manual chapter 6, www.100ask.net) */

typedef struct {

    S3C24X0_REG32   NFCONF;

    S3C24X0_REG32   NFCONT;

    S3C24X0_REG32   NFCMD;

    S3C24X0_REG32   NFADDR;

    S3C24X0_REG32   NFDATA;

    S3C24X0_REG32   NFMECCD0;

    S3C24X0_REG32   NFMECCD1;

    S3C24X0_REG32   NFSECCD;

    S3C24X0_REG32   NFSTAT;

    S3C24X0_REG32   NFESTAT0;

    S3C24X0_REG32   NFESTAT1;

    S3C24X0_REG32   NFMECC0;

    S3C24X0_REG32   NFMECC1;

    S3C24X0_REG32   NFSECC;

    S3C24X0_REG32   NFSBLK;

    S3C24X0_REG32   NFEBLK;

} S3C2440_NAND;

typedef struct {

    void (*nand_reset)(void);

    void (*wait_idle)(void);

    void (*nand_select_chip)(void);

    void (*nand_deselect_chip)(void);

    void (*write_cmd)(int cmd);

    void (*write_addr)(unsigned int addr);

    unsigned char (*read_data)(void);

}t_nand_chip;

static S3C2410_NAND * s3c2410nand = (S3C2410_NAND *)0x4e000000;

static S3C2440_NAND * s3c2440nand = (S3C2440_NAND *)0x4e000000;

static t_nand_chip nand_chip;

/* 供外部调用的函数 */

void nand_init(void);

void nand_read(unsigned char *buf, unsigned long start_addr, int size);

/* NAND Flash操作的总入口, 它们将调用S3C2410或S3C2440的相应函数 */

static void nand_reset(void);

static void wait_idle(void);

static void nand_select_chip(void);

static void nand_deselect_chip(void);

static void write_cmd(int cmd);

static void write_addr(unsigned int addr);

static unsigned char read_data(void);

/* S3C2410的NAND Flash处理函数 */

static void s3c2410_nand_reset(void);

static void s3c2410_wait_idle(void);

static void s3c2410_nand_select_chip(void);

static void s3c2410_nand_deselect_chip(void);

static void s3c2410_write_cmd(int cmd);

static void s3c2410_write_addr(unsigned int addr);

static unsigned char s3c2410_read_data();

/* S3C2440的NAND Flash处理函数 */

static void s3c2440_nand_reset(void);

static void s3c2440_wait_idle(void);

static void s3c2440_nand_select_chip(void);

static void s3c2440_nand_deselect_chip(void);

static void s3c2440_write_cmd(int cmd);

static void s3c2440_write_addr(unsigned int addr);

static unsigned char s3c2440_read_data(void);

/* S3C2410的NAND Flash操作函数 */

/* 复位 */

static void s3c2410_nand_reset(void)

{

    s3c2410_nand_select_chip();

    s3c2410_write_cmd(0xff);  // 复位命令

    s3c2410_wait_idle();

    s3c2410_nand_deselect_chip();

}

/* 等待NAND Flash就绪 */

static void s3c2410_wait_idle(void)

{

    int i;

    volatile unsigned char *p = (volatile unsigned char *)&s3c2410nand->NFSTAT;

    while(!(*p & BUSY))

        for(i=; i<; i++);

}

/* 发出片选信号 */

static void s3c2410_nand_select_chip(void)

{

    int i;

    s3c2410nand->NFCONF &= ~(<<);

    for(i=; i<; i++);

}

/* 取消片选信号 */

static void s3c2410_nand_deselect_chip(void)

{

    s3c2410nand->NFCONF |= (<<);

}

/* 发出命令 */

static void s3c2410_write_cmd(int cmd)

{

    volatile unsigned char *p = (volatile unsigned char *)&s3c2410nand->NFCMD;

    *p = cmd;

}

/* 发出地址 */

static void s3c2410_write_addr(unsigned int addr)

{

    int i;

    volatile unsigned char *p = (volatile unsigned char *)&s3c2410nand->NFADDR;

    *p = addr & 0xff;

    for(i=; i<; i++);

    *p = (addr >> ) & 0xff;

    for(i=; i<; i++);

    *p = (addr >> ) & 0xff;

    for(i=; i<; i++);

    *p = (addr >> ) & 0xff;

    for(i=; i<; i++);

}

/* 读取数据 */

static unsigned char s3c2410_read_data(void)

{

    volatile unsigned char *p = (volatile unsigned char *)&s3c2410nand->NFDATA;

    return *p;

}

/* S3C2440的NAND Flash操作函数 */

/* 复位 */

static void s3c2440_nand_reset(void)

{

    s3c2440_nand_select_chip();

    s3c2440_write_cmd(0xff);  // 复位命令

    s3c2440_wait_idle();

    s3c2440_nand_deselect_chip();

}

/* 等待NAND Flash就绪 */

static void s3c2440_wait_idle(void)

{

    int i;

    volatile unsigned char *p = (volatile unsigned char *)&s3c2440nand->NFSTAT;

    while(!(*p & BUSY))

        for(i=; i<; i++);

}

/* 发出片选信号 */

static void s3c2440_nand_select_chip(void)

{

    int i;

    s3c2440nand->NFCONT &= ~(<<);

    for(i=; i<; i++);

}

/* 取消片选信号 */

static void s3c2440_nand_deselect_chip(void)

{

    s3c2440nand->NFCONT |= (<<);

}

/* 发出命令 */

static void s3c2440_write_cmd(int cmd)

{

    volatile unsigned char *p = (volatile unsigned char *)&s3c2440nand->NFCMD;

    *p = cmd;

}

/* 发出地址 */

static void s3c2440_write_addr(unsigned int addr)

{

    int i;

    volatile unsigned char *p = (volatile unsigned char *)&s3c2440nand->NFADDR;

    *p = addr & 0xff;

    for(i=; i<; i++);

    *p = (addr >> ) & 0xff;

    for(i=; i<; i++);

    *p = (addr >> ) & 0xff;

    for(i=; i<; i++);

    *p = (addr >> ) & 0xff;

    for(i=; i<; i++);

}

static void s3c2440_write_addr_lp(unsigned int addr)

{

    int i;

    volatile unsigned char *p = (volatile unsigned char *)&s3c2440nand->NFADDR;

    int col, page;

    col = addr & NAND_BLOCK_MASK_LP;

    page = addr / NAND_SECTOR_SIZE_LP;

    *p = col & 0xff;            /* Column Address A0~A7 */

    for(i=; i<; i++);

    *p = (col >> ) & 0x0f;     /* Column Address A8~A11 */

    for(i=; i<; i++);

    *p = page & 0xff;            /* Row Address A12~A19 */

    for(i=; i<; i++);

    *p = (page >> ) & 0xff;    /* Row Address A20~A27 */

    for(i=; i<; i++);

    *p = (page >> ) & 0x03;    /* Row Address A28~A29 */

    for(i=; i<; i++);

}

/* 读取数据 */

static unsigned char s3c2440_read_data(void)

{

    volatile unsigned char *p = (volatile unsigned char *)&s3c2440nand->NFDATA;

    return *p;

}

/* 在第一次使用NAND Flash前，复位一下NAND Flash */

static void nand_reset(void)

{

    nand_chip.nand_reset();

}

static void wait_idle(void)

{

    nand_chip.wait_idle();

}

static void nand_select_chip(void)

{

    int i;

    nand_chip.nand_select_chip();

    for(i=; i<; i++);

}

static void nand_deselect_chip(void)

{

    nand_chip.nand_deselect_chip();

}

static void write_cmd(int cmd)

{

    nand_chip.write_cmd(cmd);

}

static void write_addr(unsigned int addr)

{

    nand_chip.write_addr(addr);

}

static unsigned char read_data(void)

{

    return nand_chip.read_data();

}

/* 初始化NAND Flash */

void nand_init(void)

{

#define TACLS   0

#define TWRPH0  3

#define TWRPH1  0

    /* 判断是S3C2410还是S3C2440 */

    if ((GSTATUS1 == 0x32410000) || (GSTATUS1 == 0x32410002))

    {

        nand_chip.nand_reset         = s3c2410_nand_reset;

        nand_chip.wait_idle          = s3c2410_wait_idle;

        nand_chip.nand_select_chip   = s3c2410_nand_select_chip;

        nand_chip.nand_deselect_chip = s3c2410_nand_deselect_chip;

        nand_chip.write_cmd          = s3c2410_write_cmd;

        nand_chip.write_addr         = s3c2410_write_addr;

        nand_chip.read_data          = s3c2410_read_data;

        /* 使能NAND Flash控制器, 初始化ECC, 禁止片选, 设置时序 */

        s3c2410nand->NFCONF = (<<)|(<<)|(<<)|(TACLS<<)|(TWRPH0<<)|(TWRPH1<<);

    }

    else

    {

        nand_chip.nand_reset         = s3c2440_nand_reset;

        nand_chip.wait_idle          = s3c2440_wait_idle;

        nand_chip.nand_select_chip   = s3c2440_nand_select_chip;

        nand_chip.nand_deselect_chip = s3c2440_nand_deselect_chip;

        nand_chip.write_cmd          = s3c2440_write_cmd;

#ifdef LARGER_NAND_PAGE

        nand_chip.write_addr         = s3c2440_write_addr_lp;

#else

        nand_chip.write_addr         = s3c2440_write_addr;

#endif

        nand_chip.read_data          = s3c2440_read_data;

        /* 设置时序 */

        s3c2440nand->NFCONF = (TACLS<<)|(TWRPH0<<)|(TWRPH1<<);

        /* 使能NAND Flash控制器, 初始化ECC, 禁止片选 */

        s3c2440nand->NFCONT = (<<)|(<<)|(<<);

    }

    /* 复位NAND Flash */

    nand_reset();

}

/* 读函数 */

void nand_read(unsigned char *buf, unsigned long start_addr, int size)

{

    int i, j;

#ifdef LARGER_NAND_PAGE

    if ((start_addr & NAND_BLOCK_MASK_LP) || (size & NAND_BLOCK_MASK_LP)) {

        return ;    /* 地址或长度不对齐 */

    }

#else

    if ((start_addr & NAND_BLOCK_MASK) || (size & NAND_BLOCK_MASK)) {

        return ;    /* 地址或长度不对齐 */

    }

#endif    

    /* 选中芯片 */

    nand_select_chip();

    for(i=start_addr; i < (start_addr + size);) {

      /* 发出READ0命令 */

      write_cmd();

      /* Write Address */

      write_addr(i);

#ifdef LARGER_NAND_PAGE

      write_cmd(0x30);

#endif

      wait_idle();

#ifdef LARGER_NAND_PAGE

      for(j=; j < NAND_SECTOR_SIZE_LP; j++, i++) {

#else

      for(j=; j < NAND_SECTOR_SIZE; j++, i++) {

#endif

          *buf = read_data();

          buf++;

      }

    }

    /* 取消片选信号 */

    nand_deselect_chip();

    return ;

}

uart.c 源码：

#include"uart.h"

//uart

#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  UERSTAT0    (*(volatile unsigned long *)0x50000014)

#define  UTXH0       (*(volatile unsigned char *)0x50000020)

#define  URXH0       (*(volatile unsigned char *)0x50000024)

#define  UBRDIV0     (*(volatile unsigned long *)0x50000028)

//GPH

#define  GPHCON      (*(volatile unsigned long *)0x56000070)

#define  GPHDAT      (*(volatile unsigned long *)0x56000074)

#define  GPHUP       (*(volatile unsigned long *)0x56000078)

void uart0_init(void)

{

    GPHCON|=0xa0;

    GPHUP=0x0c;

    ULCON0=0x03;

    UCON0=0x05;

    UFCON0=0x00;

    UMCON0=0x00;

    UBRDIV0=((/(*))-);

}

unsigned char my_getchar(void)

{

    while(!(UTRSTAT0 & 0x01));

    return URXH0;

}

void my_putchar(unsigned char date)

{

    while(!(UTRSTAT0 & 0x02));

    UTXH0=date;

}

unsigned char getc(void)

{

     while(!(UTRSTAT0 & 0x01));

     return URXH0;

}

void putc(unsigned char c)

{

    while(!(UTRSTAT0 & 0x02));

    UTXH0=c;

}

uart.h 源码：

#ifndef _UART_H_

#define _UART_H_ 

void uart0_init(void);

unsigned char my_getchar(void);

void my_putchar(unsigned char date);

unsigned char getc(void);

void putc(unsigned char c);

#endif

my_stdio.c 源码：

#include"uart.h"

#include"my_stdio.h"

typedef char* va_list;

#define int_sizeof(type)             ((sizeof(int)+sizeof(type)-1)&~(sizeof(int)-1))

#define va_start(para_p,first_para)  (para_p=(va_list)&first_para+int_sizeof(first_para))

#define va_arg(para_p,type)          (*(type *)((para_p+=int_sizeof(type))-int_sizeof(type)))

#define va_end(para_p)               (para_p=(va_list)0)  

void my_printf(const char *format, ...)

{

    va_list temp ;

    char *string = format;

    va_start(temp, format);    

    while (*string)

    {

        if (*string == '%')

        {

            switch (*++string)

            {

               case 'c':     {  my_putchar(va_arg(temp,char)); break; }

               case 's':

               {

                   char* p = va_arg(temp,char*);

                   while (*p != ) my_putchar(*p++);

                   break;

               }

               case 'p':

               {

                   unsigned int addr = (unsigned int)&va_arg(temp, unsigned int), sheft = 0xf0000000;

                   unsigned char temp = ,count=;

                   my_putchar('');

                   my_putchar('x');

                   while (count<)

                   {

                       temp = (unsigned char)(((sheft >> count)&addr) >> ( - count - )) ;

                       if (temp < ) my_putchar(temp + );

                       if (temp >= ) my_putchar(temp+-);

                       count += ;

                   }

                   break;

               }

               case 'd':

               {

                   int value = va_arg(temp, int),num=;

                   if (value == ) my_putchar();

                   if (value & 0x80000000)    //负数

                   {

                       my_putchar('-');

                       num = -;

                   }

                   else                       //正数.;

                   while (!(value / num))

                           {

                               num /= ;

                               if (num == )

                               {

                                   my_putchar();

                                   return;

                               }

                            }

                          while (num != )

                               {

                                   my_putchar(value / num+);

                                   value %= num;

                                   num /= ;

                               }

                          break;

               }

               case 'f':

               {

                   char *str = "Sorry: function is not available";

                   while (*str != ) my_putchar(*str++);

               }

            default: break;

            }

        }

        string++;

    }

    va_end(temp);

}

my_stdio.h 源码：

#ifndef  _OWN_STDIO_H_

#define  _OWN_STDIO_H_

void my_printf(const char *format,...);

#endif

main.c 源码：

#include"uart.h"

#include"my_stdio.h"

#include"stdio.h"

void raise(int sig_nr){;}

int main(void)

{

    uart0_init();

    printf("%s","   wds_standard   ");

    my_printf("%s","  zsy_standard   ");

    while()

    my_putchar(my_getchar()+);    

    return ;

}

链接脚本 uart.lds ：

SECTIONS

{

  . = 0x00000000;

  .init : AT(){start.o init.o nand.o}

  . = 0x30000000;

  .text : AT(){*(.text)}

  .rodata ALIGN() :  AT((LOADADDR(.text)+SIZEOF(.text)+)&~(0x03)) {*(.rodata*)}

  .data  ALIGN() :  AT((LOADADDR(.rodata)+SIZEOF(.rodata)+)&~(0x03)) {*(.data)}

  .bss   : {*(.bss) *(COMMON)}

}

Makefile:

objs:= start.o init.o uart.o nand.o main.o my_stdio.o lib/libc.a

CC            =arm-linux-gcc

LD            =arm-linux-ld

AR            =arm-linux-ar

OBJCOPY       =arm-linux-objcopy

OBJDUMP       =arm-linux-objdump

INCLUDEDIR    :=$(shell pwd)/include

CFLAGS        :=-Wall -O2

CPPFLAGS      :=-nostdinc -I$(INCLUDEDIR)

export     CC LD OBJCOPY OBJDUMP INCLUDEDIR CFLAGS CPPFLAGS

uart.bin:$(objs)

    arm-linux-ld -Tuart.lds -o uart_elf $^ libgcc.a

    arm-linux-objcopy -O binary -S uart_elf $@

    arm-linux-objdump -D -m arm uart_elf > uart.dis

.PHONY:lib/libc.a

lib/libc.a:

    cd lib;make;cd ..

%.o:%.s

    $(CC) $(CPPFLAGS) $(FLAGS)-o $@ -c $<

%.o:%.c

    $(CC) $(CPPFLAGS) $(FLAGS) -o $@ -c $<

clean:

    make  clean -C lib

    rm -f *.o *.bin *.dis uart_elf

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