1、前将这五个打印文件拷贝进来
2、要点
arm-linux-gcc -march=armv4 -c -o $@ $< -march=armv4的意思是防止两字节被拆开放入到内存中，如下
3、要点，要左移八位，以为是后面两个字节平起来的，00和40
编译程序时加上: -march=armv4
否则
volatile unsigned short *p = xxx;
*p = val; // 会被拆分成2个strb操作
4、要点
把timer中断去掉
否则: 测试nor时进入CFI等模式时, 如果发生了中断，cpu必定读NOR，
那么读不到正确的指令，导致程序崩溃
5、要点
val = nor_dat(addr>>1); 发送要写的地址的时候不要移动，因为在nor_read_word已经右移了，所以这里左移。
6、要点，通过两次读取到的数据去判断第六位是否相等。
7、记得要屏蔽掉中断相关的功能
8、代码示例
#include "my_printf.h"
#include "string_utils.h"
#define NOR_FLASH_BASE 0 /* jz2440, nor-->cs0, base addr = 0 */
/* 比如: 55H 98
* 本意是: 往(0 + (0x55)<<1)写入0x98
*/
void nor_write_word(unsigned int base, unsigned int offset, unsigned int val)
{
volatile unsigned short *p = (volatile unsigned short *)(base + (offset << 1));
*p = val;
}
/* offset是基于NOR的角度看到 */
void nor_cmd(unsigned int offset, unsigned int cmd)
{
nor_write_word(NOR_FLASH_BASE, offset, cmd);
}
unsigned int nor_read_word(unsigned int base, unsigned int offset)
{
volatile unsigned short *p = (volatile unsigned short *)(base + (offset << 1));
return *p;
}
unsigned int nor_dat(unsigned int offset)
{
return nor_read_word(NOR_FLASH_BASE, offset);
}
void wait_ready(unsigned int addr)
{
unsigned int val;
unsigned int pre;
pre = nor_dat(addr>>1);
val = nor_dat(addr>>1);
while ((val & (1<<6)) != (pre & (1<<6)))
{
pre = val;
val = nor_dat(addr>>1);
}
}
/* 进入NOR FLASH的CFI模式
* 读取各类信息
*/
void do_scan_nor_flash(void)
{
char str[4];
unsigned int size;
int regions, i;
int region_info_base;
int block_addr, blocks, block_size, j;
int cnt;
int vendor, device;
/* 打印厂家ID、设备ID */
nor_cmd(0x555, 0xaa); /* 解锁 */
nor_cmd(0x2aa, 0x55);
nor_cmd(0x555, 0x90); /* read id */
vendor = nor_dat(0);
device = nor_dat(1);
nor_cmd(0, 0xf0); /* reset */
nor_cmd(0x55, 0x98); /* 进入cfi模式 */
str[0] = nor_dat(0x10);
str[1] = nor_dat(0x11);
str[2] = nor_dat(0x12);
str[3] = '\0';
printf("str = %s\n\r", str);
/* 打印容量 */
size = 1<<(nor_dat(0x27));
printf("vendor id = 0x%x, device id = 0x%x, nor size = 0x%x, %dM\n\r", vendor, device, size, size/(1024*1024));
/* 打印各个扇区的起始地址 */
/* 名词解释:
* erase block region : 里面含有1个或多个block, 它们的大小一样
* 一个nor flash含有1个或多个region
* 一个region含有1个或多个block(扇区)
* Erase block region information:
* 前2字节+1 : 表示该region有多少个block
* 后2字节*256 : 表示block的大小
*/
regions = nor_dat(0x2c);
region_info_base = 0x2d;
block_addr = 0;
printf("Block/Sector start Address:\n\r");
cnt = 0;
for (i = 0; i < regions; i++)
{
blocks = 1 + nor_dat(region_info_base) + (nor_dat(region_info_base+1)<<8);
block_size = 256 * (nor_dat(region_info_base+2) + (nor_dat(region_info_base+3)<<8));
region_info_base += 4;
// printf("\n\rregion %d, blocks = %d, block_size = 0x%x, block_addr = 0x%x\n\r", i, blocks, block_size, block_addr);
for (j = 0; j < blocks; j++)
{
/* 打印每个block的起始地址 */
//printf("0x%08x ", block_addr);
printHex(block_addr);
putchar(' ');
cnt++;
block_addr += block_size;
if (cnt % 5 == 0)
printf("\n\r");
}
}
printf("\n\r");
/* 退出CFI模式 */
nor_cmd(0, 0xf0);
}
void do_erase_nor_flash(void)
{
unsigned int addr;
/* 获得地址 */
printf("Enter the address of sector to erase: ");
addr = get_uint();
printf("erasing ...\n\r");
nor_cmd(0x555, 0xaa); /* 解锁 */
nor_cmd(0x2aa, 0x55);
nor_cmd(0x555, 0x80); /* erase sector */
nor_cmd(0x555, 0xaa); /* 解锁 */
nor_cmd(0x2aa, 0x55);
nor_cmd(addr>>1, 0x30); /* 发出扇区地址 */
wait_ready(addr);
}
void do_write_nor_flash(void)
{
unsigned int addr;
unsigned char str[100];
int i, j;
unsigned int val;
/* 获得地址 */
printf("Enter the address of sector to write: ");
addr = get_uint();
printf("Enter the string to write: ");
gets(str);
printf("writing ...\n\r");
/* str[0],str[1]==>16bit
* str[2],str[3]==>16bit
*/
i = 0;
j = 1;
while (str[i] && str[j])
{
val = str[i] + (str[j]<<8);
/* 烧写 */
nor_cmd(0x555, 0xaa); /* 解锁 */
nor_cmd(0x2aa, 0x55);
nor_cmd(0x555, 0xa0); /* program */
nor_cmd(addr>>1, val);
/* 等待烧写完成 : 读数据, Q6无变化时表示结束 */
wait_ready(addr);
i += 2;
j += 2;
addr += 2;
}
val = str[i];
/* 烧写 */
nor_cmd(0x555, 0xaa); /* 解锁 */
nor_cmd(0x2aa, 0x55);
nor_cmd(0x555, 0xa0); /* program */
nor_cmd(addr>>1, val);
/* 等待烧写完成 : 读数据, Q6无变化时表示结束 */
wait_ready(addr);
}
void do_read_nor_flash(void)
{
unsigned int addr;
volatile unsigned char *p;
int i, j;
unsigned char c;
unsigned char str[16];
/* 获得地址 */
printf("Enter the address to read: ");
addr = get_uint();
p = (volatile unsigned char *)addr;
printf("Data : \n\r");
/* 长度固定为64 */
for (i = 0; i < 4; i++)
{
/* 每行打印16个数据 */
for (j = 0; j < 16; j++)
{
/* 先打印数值 */
c = *p++;
str[j] = c;
printf("%02x ", c);
}
printf(" ; ");
for (j = 0; j < 16; j++)
{
/* 后打印字符 */
if (str[j] < 0x20 || str[j] > 0x7e) /* 不可视字符 */
putchar('.');
else
putchar(str[j]);
}
printf("\n\r");
}
}
void nor_flash_test(void)
{
char c;
while (1)
{
/* 打印菜单, 供我们选择测试内容 */
printf("[s] Scan nor flash\n\r");
printf("[e] Erase nor flash\n\r");
printf("[w] Write nor flash\n\r");
printf("[r] Read nor flash\n\r");
printf("[q] quit\n\r");
printf("Enter selection: ");
c = getchar();
printf("%c\n\r", c);
/* 测试内容:
* 1. 识别nor flash
* 2. 擦除nor flash某个扇区
* 3. 编写某个地址
* 4. 读某个地址
*/
switch (c)
{
case 'q':
case 'Q':
return;
break;
case 's':
case 'S':
do_scan_nor_flash();
break;
case 'e':
case 'E':
do_erase_nor_flash();
break;
case 'w':
case 'W':
do_write_nor_flash();
break;
case 'r':
case 'R':
do_read_nor_flash();
break;
default:
break;
}
}
}