u启动4k齐教程-(u盘4k对齐设置)

然后重新编译成功编译。

(1) 以前写的init.c文件放到board/samsung/jz2440目录，init.c文件代码如下：

/*所以如何判断是NOR启动还是NAND启动呢? 可以利用NOR的特点: *1.NOR可以像内存一样读，但不能像内存一样写； *2.可以通过向0地址写数据来区分NAND启动还是NOR启动; *(因为NAND启动时，0地址是RAM，可读可写；但是NOR启动时，0地址是NOR FLASH，可读不能写) *返回值：1：Nor启动； 0：NAND启动 */#define NFCONF (*((volatile unsigned long *)0x4E000000))#define NFCONT (*((volatile unsigned long *)0x4E000004))#define NFCMMD (*((volatile unsigned char *)0x4E000008))#define NFADDR (*((volatile unsigned char *)0x4E00000c))#define NFDATA (*((volatile unsigned char *)0x4E000010))#define NFSTAT (*((volatile unsigned long *)0x4E000020))/* GPIO */#define GPHCON (*(volatile unsigned long *)0x56000070)#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)#define TXD0READY (1<<2)/* NAND flash 设置时序(需要比较)s3c2440与NAND手册的NAND时序) * */void nand_init_ll(void){ /*设置NANDFlash时序*/#define TACLS 0#define TWRPH0 1#define TWRPH1 0 NFCONF &= ~((3<<12)|(7<<8)|(7<<4)); NFCONF |= (TACLS<<12)|(TWRPH0<<8)|(TWRPH1<<4); /*使能NANDflash 控制器， *禁止片选(开发板没有正式使用片选，避免操作错误) *初始化 ECC 编码器/译码器*/ NFCONT = (1<<0)|(1<<1)|(1<<4);}static void nand_cmd(unsigned char cmd){ volatile int i; NFCMMD = cmd; for(i = 0; i < 10; i );/*等待*/}static void nand_addr(unsigned int addr){ unsigned int col = addr % 2048; unsigned int page = addr / 2048; volatile int i; NFADDR = col & 0xff; for(i = 0; i < 10; i );/*等待*/ NFADDR = (col >> 8) & 0xff; for(i = 0; i < 10; i );/*等待*/ NFADDR = page & 0xff; for(i = 0; i < 10; i );/*等待*/ NFADDR = (page >> 8) & 0xff; for(i = 0; i < 10; i );/*等待*/ NFADDR = (page >> 16) & 0xff; for(i = 0; i < 10; i );/*等待*/}static void nand_wait_ready(void){ while(!(NFSTAT & 0x01));}static unsigned char nand_data(void){ return NFDATA;}static void nand_select(void){ NFCONT &= ~(1<<1);}static void nand_deselect(void){ NFCONT |= (1<<1);}void nand_read_ll(unsigned int addr, unsigned char *buf,unsigned int len){ int col = addr % 2048; int i = 0; /*1.片选*/ nand_select(); while(i < len){ /*2.发出00阅读命令h*/ nand_cmd(0x00); /*3.发出地址(分为5个地址周期)*/ nand_addr(addr); /*4.发出30个阅读命令h*/ nand_cmd(0x30); /*5.等待就绪(判断状态)*/ nand_wait_ready(); /*6.读数据*/ for(; (col < 2048) && (i < len); col ){ buf[i]= nand_data(); i ; addr ; }col = 0; }/*7.取消选中*/ nand_deselect();}static int isBootFromNorFlash(void){ volatile unsigned int *p = (volatile unsigned int*)0; unsigned int val; val = *p; *p = 0x12345678; if(*p == val) /*写前写后值一样，证明数据不能写0地址，是NOR启动*/{ return 1; }else /*否则是NAND启动*/{ *p = val; /*恢复数据*/ return 0; }}void copy_code_to_sdram(unsigned char *src, unsigned char *dest,unsigned int len){ unsigned int i=0; /*如果是NOR启动*/ if(isBootFromNorFlash()) /*所以如何判断是NOR启动还是NAND启动呢? */{ while(i < len){ dest[i]= src[i]; i ; }}else /*否则是NAND启动*/{ nand_init_ll();/*初始化NAND*/ nand_read_ll((unsigned int )src,dest,len); }}/*c如何引用连接脚本的语言？ __bss_start、__bss_end等变量呢？ * extern int __bs s_