Linux学习 ： 裸板调试 之 配置使用NAND FLASH
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关于NAND FLASH的结构是以页为单位写，以块为单位来擦除：
1Gb 为大页 page=2048Kb BLOCK=128K
512Mb 为小页 page=512byte BLOCK=16K
PS:一页还有额外64字节OOB块，通常不计入读取范围。
另一个区别就是ECC的验证:
ECC是每256个字节生产一个24位的值。NAND FLASH在写的时候会生成一个原始的ECC值保存在页的SPARE区，当要读页时也会生产一个ECC值，会跟SPARE的值进行异或比较，看结果是否为0，所有在大页换小页的时候，一定要修改这个算法，相反也是大页需要8对ECC 小页只需要2对ECC。
实验平台:s3c2440 , Nand Flash Size:256M
1、Nand Flash 控制代码部分：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) */ 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=0; i<10; i++); } /* 发出片选信号 */ static void s3c2410_nand_select_chip(void) { int i; s3c2410nand->NFCONF &= ~(1<<11); for(i=0; i<10; i++); } /* 取消片选信号 */ static void s3c2410_nand_deselect_chip(void) { s3c2410nand->NFCONF |= (1<<11); } /* 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=0; i<10; i++); *p = (addr >> 9) & 0xff; for(i=0; i<10; i++); *p = (addr >> 17) & 0xff; for(i=0; i<10; i++); *p = (addr >> 25) & 0xff; for(i=0; i<10; 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=0; i<10; i++); } /* 发出片选信号 */ static void s3c2440_nand_select_chip(void) { int i; s3c2440nand->NFCONT &= ~(1<<1); for(i=0; i<10; i++); } /* 取消片选信号 */ static void s3c2440_nand_deselect_chip(void) { s3c2440nand->NFCONT |= (1<<1); } /* 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=0; i<10; i++); *p = (addr >> 9) & 0xff; for(i=0; i<10; i++); *p = (addr >> 17) & 0xff; for(i=0; i<10; i++); *p = (addr >> 25) & 0xff; for(i=0; i<10; 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=0; i<10; i++); *p = (col >> 8) & 0x0f; /* Column Address A8~A11 */ for(i=0; i<10; i++); *p = page & 0xff; /* Row Address A12~A19 */ for(i=0; i<10; i++); *p = (page >> 8) & 0xff; /* Row Address A20~A27 */ for(i=0; i<10; i++); *p = (page >> 16) & 0x03; /* Row Address A28~A29 */ for(i=0; i<10; 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=0; i<10; 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 = (1<<15)|(1<<12)|(1<<11)|(TACLS<<8)|(TWRPH0<<4)|(TWRPH1<<0); } 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<<12)|(TWRPH0<<8)|(TWRPH1<<4); /* 使能NAND Flash控制器, 初始化ECC, 禁止片选 */ s3c2440nand->NFCONT = (1<<4)|(1<<1)|(1<<0); } /* 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(0); /* Write Address */ write_addr(i); #ifdef LARGER_NAND_PAGE write_cmd(0x30); #endif wait_idle(); #ifdef LARGER_NAND_PAGE for(j=0; j < NAND_SECTOR_SIZE_LP; j++, i++) { #else for(j=0; j < NAND_SECTOR_SIZE; j++, i++) { #endif *buf = read_data(); buf++; } } /* 取消片选信号 */ nand_deselect_chip(); return ; }
2、初始化SDRAM: init.c
/* WOTCH DOG register */ #define WTCON (*(volatile unsigned long *)0x53000000) /* SDRAM regisers */ #define MEM_CTL_BASE 0x48000000 void disable_watch_dog(); void memsetup(); /*上电后，WATCH DOG默认是开着的，要把它关掉 */ void disable_watch_dog() { WTCON = 0; } /* 设置控制SDRAM的13个寄存器 */ void memsetup() { int i = 0; unsigned long *p = (unsigned long *)MEM_CTL_BASE; /* SDRAM 13个寄存器的值 */ unsigned long const mem_cfg_val[]={ 0x22011110, //BWSCON 0x00000700, //BANKCON0 0x00000700, //BANKCON1 0x00000700, //BANKCON2 0x00000700, //BANKCON3 0x00000700, //BANKCON4 0x00000700, //BANKCON5 0x00018005, //BANKCON6 0x00018005, //BANKCON7 0x008C07A3, //REFRESH 0x000000B1, //BANKSIZE 0x00000030, //MRSRB6 0x00000030, //MRSRB7 }; for(; i < 13; i++) p[i] = mem_cfg_val[i]; }
3、led操作: main.c
#define GPFCON (*(volatile unsigned long *)0x56000050) #define GPFDAT (*(volatile unsigned long *)0x56000054) #define GPF4_out (1<<(4*2)) #define GPF5_out (1<<(5*2)) #define GPF6_out (1<<(6*2)) void wait(volatile unsigned long dly) { for(; dly > 0; dly--); } int main(void) { unsigned long i = 0; GPFCON = GPF4_out|GPF5_out|GPF6_out; // 将LED1-3对应的GPF4/5/6三个引脚设为输出 while(1){ wait(30000); GPFDAT = (~(i<<4)); // 根据i的值，点亮LED1-3 if(++i == 8) i = 0; } return 0; }
4、汇编调用部分：
@****************************************************************************** @ File：head.s @ 功能：设置SDRAM，将程序复制到SDRAM，然后跳到SDRAM继续执行 @****************************************************************************** .text .global _start _start: @函数disable_watch_dog, memsetup, init_nand, nand_read_ll在init.c中定义 ldr sp, =4096 @设置堆栈 bl disable_watch_dog @关WATCH DOG bl memsetup @初始化SDRAM bl nand_init @初始化NAND Flash @将NAND Flash中地址4096开始的1024字节代码(main.c编译得到)复制到SDRAM中 @nand_read_ll函数需要3个参数： ldr r0, =0x30000000 @1. 目标地址=0x30000000，这是SDRAM的起始地址 mov r1, #4096 @2. 源地址 = 4096，连接的时候，main.c中的代码都存在NAND Flash地址4096开始处 mov r2, #2048 @3. 复制长度= 2048(bytes)，对于本实验的main.c，这是足够了 bl nand_read @调用C函数nand_read ldr sp, =0x34000000 @设置栈 ldr lr, =halt_loop @设置返回地址 ldr pc, =main @b指令和bl指令只能前后跳转32M的范围，所以这里使用向pc赋值的方法进行跳转 halt_loop: b halt_loop
5、链接地址指定，验证读取2049地址的数据：nand.lds
SECTIONS { firtst 0x00000000 : { head.o init.o nand.o} second 0x30000000 : AT(4096) { main.o } }
6、Makefile
objs := head.o init.o nand.o main.o nand.bin : $(objs) arm-linux-ld -Tnand.lds -o nand_elf $^ arm-linux-objcopy -O binary -S nand_elf [email protected] arm-linux-objdump -D -m arm nand_elf > nand.dis %.o:%.c arm-linux-gcc -Wall -c -O2 -o [email protected] $< %.o:%.S arm-linux-gcc -Wall -c -O2 -o [email protected] $< clean: rm -f nand.dis nand.bin nand_elf *.o
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