文件系统转换 Bootloader之uBoot简介（转）(33)

既然skipfirstblk是在nand_write_options_t结构中新加的项，那么就要重新定义nand_write_options_t结构，并在下面调用的nand_write_opts函数中对它进行处理。

首先在include/nand.h中如下修改，增加skipfirstblk成员：

struct nand_write_options {

u_char *buffer;/* memory block containing image to write */

ulong length;/* number of bytes to write */

ulong offset;/* start address in NAND */

int quiet;/* don't display progress messages */

int autoplace;/* if true use auto oob layout */

int forcejffs2;/* force jffs2 oob layout */

int forceyaffs;/* force yaffs oob layout */

int noecc;/* write without ecc */

int writeoob;/* image contains oob data */

int pad;/* pad to page size */

int blockalign;/* 1|2|4 set multiple of eraseblocks to align to */

int skipfirstblk; /* 新加，烧写时跳过第一个可用的逻辑块 */

};

typedef struct nand_write_options nand_write_options_t;

然后，修改nand_write_opts函数增加对skipfirstblk成员的支持。它在drivers/nand/nand_util.c文件中，下面的第301、第430～435行是新加的：

285 int nand_write_opts(nand_info_t *meminfo, const nand_write_options_t *opts)

286 {

……

300 int result;

301 int skipfirstblk = opts->skipfirstblk;

……

430 /* skip the first good block when wirte yaffs image, by */

431 if (skipfirstblk) {

432 mtdoffset += erasesize_blockalign;

433 skipfirstblk = 0;

434 continue;

435 }

……

进行了上面的移植后，U-Boot已经可以烧yaffs文件系统映像了。由于前面设置“opts.noecc = 1”不使用ECC较验码，在烧写过程中会出现很多的提示信息：

Writing data without ECC to NAND-FLASH is not recommended

可以修改drivers/nand/nand_base.c文件的nand_write_page函数将它去掉：

917 case NAND_ECC_NONE:

918 printk (KERN_WARNING "Writing data without ECC to NAND-FLASH is not recommended\n");

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