u-boot-2009.11移植（适用于TQ2440和MINI2440）第四篇：完善目标

注意：红色标记为修改的地方

4.1 Nand Flash相关代码的修改

在U-boot 启动的第一阶段，初始化了Nand Flash 控制器。但到第二阶段start_armboot函数还是会再次初始化Nand Flash 控制器。因为第二阶段和第一阶段的代码基本是独立的，第一阶段的代码基本只起到代码重定位的作用，到了第二阶段才是真正U-boot 的开始，以前的初始化过程还会重做一遍，比如始化Nand Flash 控制器、CPU 频率等。

因为S3C2440 和S3C2410 之间的很大差别就是：S3C2410 的Nand Flash 控制器只支持512B+16B 的Nand Flash，而S3C2440 还支持2KB+64B 的大容量Nand Flash。所以在Nand Flash 控制器上寄存器和控制流程上的差别很明显，底层驱动代码的修改也是必须的。具体的差别还是需要对比芯片数据手册的，下面是关于Nand Flash 底层驱动代码的修改：

打开/drivers/mtd/nand/s3c2410_nand.c文件

#include<s3c2410.h>????????????????????????

#include <asm/io.h>

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#define NF_BASE???? 0x4e000000

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#if defined(CONFIG_S3C2410)

#define S3C2410_NFCONF_EN? ????????(1<<15)

#define S3C2410_NFCONF_512BYTE???? (1<<14)

#define S3C2410_NFCONF_4STEP?????? (1<<13)

#define S3C2410_NFCONF_INITECC???? (1<<12)

#define S3C2410_NFCONF_nFCE??????? (1<<11)

#define S3C2410_NFCONF_TACLS(x)??? ((x)<<8)

#define S3C2410_NFCONF_TWRPH0(x)?? ((x)<<4)

#define S3C2410_NFCONF_TWRPH1(x)?? ((x)<<0)

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#define S3C2410_ADDR_NALE 4

#define S3C2410_ADDR_NCLE 8

#endif

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#if defined(CONFIG_S3C2440)

#define S3C2410_NFCONT_EN????????? (1<<0)

#define S3C2410_NFCONT_INITECC???? (1<<4)

#define S3C2410_NFCONT_nFCE??????? (1<<1)

#define S3C2410_NFCONT_MAINECCLOCK(1<<5)

#define S3C2410_NFCONF_TACLS(x)??? ((x)<<12)

#define S3C2410_NFCONF_TWRPH0(x)?? ((x)<<8)

#define S3C2410_NFCONF_TWRPH1(x)?? ((x)<<4)

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#define S3C2410_ADDR_NALE 0x08

#define S3C2410_ADDR_NCLE 0x0c

#endif

ulong IO_ADDR_W = NF_BASE;

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static void s3c2410_hwcontrol(struct mtd_info *mtd,int cmd,unsigned int ctrl)

{

//? structnand_chip *chip = mtd->priv;

??? structs3c2410_nand *nand = s3c2410_get_base_nand();

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??? debugX(1,"hwcontrol(): 0x%02x 0x%02xn",cmd,ctrl);

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??? if (ctrl& NAND_CTRL_CHANGE) {

//????? ulongIO_ADDR_W = (ulong)nand;

IO_ADDR_W = (ulong)nand;

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??????? if(!(ctrl & NAND_CLE))

??????????? IO_ADDR_W|= S3C2410_ADDR_NCLE;

??????? if(!(ctrl & NAND_ALE))

??????????? IO_ADDR_W|= S3C2410_ADDR_NALE;

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//????? chip->IO_ADDR_W= (void *)IO_ADDR_W;

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#if defined(CONFIG_S3C2410)

??????? if (ctrl& NAND_NCE)

??????????? writel(readl(&nand->NFCONF)& ~S3C2410_NFCONF_nFCE,

??????????? ?????? &nand->NFCONF);

??????? else

??????????? writel(readl(&nand->NFCONF)| S3C2410_NFCONF_nFCE,

??????????? ?????? &nand->NFCONF);

??? }

#endif

#if defined(CONFIG_S3C2440)

??????? if(ctrl & NAND_NCE)

??????????? writel(readl(&nand->NFCONT)& ~S3C2410_NFCONT_nFCE,

??????????? ?????? &nand->NFCONT);

??????? else

??????????? writel(readl(&nand->NFCONT)| S3C2410_NFCONT_nFCE,

??????????? ?????? &nand->NFCONT);

??? }

#endif

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??? if (cmd !=NAND_CMD_NONE)

//?????writeb(cmd,chip->IO_ADDR_W);

??????? writeb(cmd,(void *)IO_ADDR_W);

}

……….

void s3c2410_nand_enable_hwecc(struct mtd_info *mtd,int mode)

{

??? structs3c2410_nand *nand = s3c2410_get_base_nand();

??? debugX(1,"s3c2410_nand_enable_hwecc(%p,%d)n",mtd,mode);

#if defined(CONFIG_S3C2410)

??? writel(readl(&nand->NFCONF)| S3C2410_NFCONF_INITECC,&nand->NFCONF);

#endif

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#if defined(CONFIG_S3C2440)

??? writel(readl(&nand->NFCONT)| S3C2410_NFCONT_INITECC,&nand->NFCONT);

#endif

}

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………..

int board_nand_init(struct nand_chip *nand)

{

…………

debugX(1,"board_nand_init()n");

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??? writel(readl(&clk_power->CLKCON)| (1 << 4),&clk_power->CLKCON);

#if defined(CONFIG_S3C2410)

??? /* initializehardware */

??? twrph0 = 3;

??? twrph1 = 0;

??? tacls = 0;

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??? cfg = S3C2410_NFCONF_EN;

??? cfg |=S3C2410_NFCONF_TACLS(tacls - 1);

??? cfg |=S3C2410_NFCONF_TWRPH0(twrph0 - 1);

??? cfg |=S3C2410_NFCONF_TWRPH1(twrph1 - 1);

??? writel(cfg,&nand_reg->NFCONF);

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??? /* initializenand_chip data structure */

??? nand->IO_ADDR_R= nand->IO_ADDR_W = (void *)&nand_reg->NFDATA;

#endif

#if defined(CONFIG_S3C2440)

??? twrph0= 4;

??? twrph1= 2;

??? tacls= 0;

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??? cfg= 0;

??? cfg|= S3C2410_NFCONF_TACLS(tacls - 1);

??? cfg|= S3C2410_NFCONF_TWRPH0(twrph0 - 1);

??? cfg|= S3C2410_NFCONF_TWRPH1(twrph1 - 1);

??? writel(cfg,&nand_reg->NFCONF);

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??? cfg=(0<<13)|(0<<12)|(0<<10)|(0<<9)|(0<<8)|(0<<6)|(0<<5)|(1<<4)|(0<<1)|(1<<0);

??? writel(cfg,&nand_reg->NFCONT);

/* initialize nand_chip data structure */

??? nand->IO_ADDR_R= nand->IO_ADDR_W = (void *)&nand_reg->NFDATA;

#endif

/* read_buf and write_buf are default */

??? /* read_byteand write_byte are default */

4.2?修改网络相关代码

以前的U-boot 对于网络延时部分有问题，需要修改许多地方。但是现在的U-boot 网络部分已经基本不需要怎么修改了，只有在DM9000 的驱动和NFS 的TIMEOUT 参数上需要稍微修改一下：

对于 DM9000 的驱动，只是屏蔽了一点代码：

打开/drivers/net/dm9000x.c文件

static int dm9000_init(struct eth_device *dev,bd_t*bd)

{

……………

while (!(phy_read(1) & 0x20)) { /* autonegation complete bit */

??????? udelay(1000);

??????? i++;

??????? if (i == 1000) {

//????????? printf("couldnot establish linkn");

//????????? return0;

??????????? break;

??????? }

??? }

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??? /* see whatwe've got */

??? lnk = phy_read(17) >> 12;

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对于 NFS，增加了延时，否则会出现“*** ERROR: Cannot mount”的错误

打开net/nfs.c文件???????????

#define HASHES_PER_LINE 65? /* Number of "loading" hashes per line? */

#define NFS_RETRY_COUNT 30

#define NFS_TIMEOUT (10*2000UL)

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static int fs_mounted = 0;

static unsigned long rpc_id = 0;