移植环境 1,主机环境:VMare下CentOS 5.5 ,1G内存。 2,集成开发环境:Elipse IDE 3,编译编译环境:arm-linux-gcc v4.4.3,arm-none-eabi-gcc v4.5.1。 4,开发板:mini2440,2M nor flash,128M nand flash。 5,u-boot版本:u-boot-2009.08 5.1,添加Yaffs2镜像烧写功能 由于现在很多使用Nand Flash 的系统,在Linux 下都用Yaffs2作为存储数据的文件系统,甚至是根文件系统。所以在BootLoader 下能够烧写Yaffs2 映像文件变得很必要。对于Yaffs2 映像烧写的支持其实就是在烧写时,写入数据的同时,将镜像文件中的oob数据也写入到Nand Flash 的Spare 区。这和Yaffs 文件系统原理以及Nand Flash 的结构有关,注意:这里对Nand的操作是基于MTD架构方式。通常一个Nnad Flash存储设备由若干块组成,1个块由若干页组成。一般128MB以下容量的Nand Flash芯片,一页大小为528B,被依次分为2个256B的主数据区和16B的额外空间;128MB以上容量的Nand Flash芯片,一页大小通常为2KB。由于Nand Flash出现位反转的概率较大,一般在读写时需要使用ECC进行错误检验和恢复。 Yaffs/yaffs2文件系统的设计充分考虑到Nand Flash以页为存取单位等的特点,将文件组织成固定大小的段(Chunk)。以528B的页为例,Yaffs/yaffs2文件系统使用前512B存储 数据和16B的额外空间存放数据的ECC和文件系统的组织信息等(称为OOB数据)。通过OOB数据,不但能实现错误检测和坏块处理,同时还可以避免加载 时对整个存储介质的扫描,加快了文件系统的加载速度。以下是Yaffs/yaffs2文件系统页的结构说明: Yaffs页结构说明 ============================================== 字节 用途 ============================================== 0 - 511 存储数据(分为两个半部) 512 - 515 系统信息 516 数据状态字 517 块状态字 518 - 519 系统信息 520 - 522 后半部256字节的ECC 523 - 524 系统信息 525 - 527 前半部256字节的ECC ==============================================
好了,在了解Nand Flash组成和Yaffs/yaffs2文件系统结构后,我们再回到u-boot中。目前,在u-boot中已经有对Cramfs、Jffs2等文件系统的读写支持,但与带有数据校验等功能的OOB区的Yaffs/Yaffs2文件系统相比,他们是将所有文件数据简单的以线性表形式组织的。所以,我们只要在此基础上通过修改u-boot的Nand Flash读写命令,增加处理00B区域数据的功能,即可以实现对Yaffs/Yaffs2文件系统的读写支持。 实现u-boot对Yaffs或者Yaffs2文件系统的读写支持步骤如下: 【1】下面是需要修改的 4 个文件的补丁: (1)打开/common/cmd_nand.c,定位到392行,在nand操作的do_nand函数中,修改如下: if (read) ret = nand_read_skip_bad(nand, off, &size, (u_char *)addr); else ret = nand_write_skip_bad(nand, off, &size, (u_char *)addr); } #if defined(CONFIG_MTD_NAND_YAFFS2) else if (s != NULL && (!strcmp(s, ".yaffs2"))) { nand->rw_oob = 1; nand->skipfirstblk = 1; ret = nand_write_skip_bad(nand,off,&size,(u_char *)addr); nand->skipfirstblk = 0; nand->rw_oob = 0; } #endif else if (!strcmp(s, ".oob")) { /* out-of-band data */ mtd_oob_ops_t ops = { .oobbuf = (u8 *)addr, .ooblen = size, .mode = MTD_OOB_RAW }; ... ... 定位到509行附近,在Nand操作的命令集列表中添加Yaffs2对Nand的读写命令,修改如下 U_BOOT_CMD(nand, CONFIG_SYS_MAXARGS, 1, do_nand, "NAND sub-system", "info - show available NAND devices\n" "nand device [dev] - show or set current device\n" "nand read - addr off|partition size\n" "nand write - addr off|partition size\n" " read/write 'size' bytes starting at offset 'off'\n" " to/from memory address 'addr', skipping bad blocks.\n" "nand erase [clean] [off size] - erase 'size' bytes from\n" " offset 'off' (entire device if not specified)\n" #if defined(CONFIG_MTD_NAND_YAFFS2) "nand write[.yaffs2] - addr off|partition size - write `size' byte yaffs image\n" " starting at offset off' from memory address addr' (.yaffs2 for 512+16 NAND)\n" #endif "nand bad - show bad blocks\n" "nand dump[.oob] off - dump page\n" "nand scrub - really clean NAND erasing bad blocks (UNSAFE)\n" "nand markbad off [...] - mark bad block(s) at offset (UNSAFE)\n" "nand biterr off - make a bit error at offset (UNSAFE)" #ifdef CONFIG_CMD_NAND_LOCK_UNLOCK "\n" "nand lock [tight] [status]\n" " bring nand to lock state or display locked pages\n" "nand unlock [offset] [size] - unlock section" #endif ); 注意:这里只添加了yaffs2的写命令,u-boot下载用的是写功能。 (2)打开include/linux/mtd/mtd.h头文件,定位到131行,在mtd_info结构体中添加上面用到rw_oob和skipfirstblk数据成员,修改如下:
u_int32_t writesize; #if defined(CONFIG_MTD_NAND_YAFFS2) /*Thanks for hugerat's code*/ u_char rw_oob; u_char skipfirstblk; #endif u_int32_t oobsize; /* Amount of OOB data per block (e.g. 16) */ u_int32_t oobavail; /* Available OOB bytes per block */
(3)在第一步关联的nand_write_skip_bad函数中添加对Nand OOB的相关操作,修改如下: 打开/drivers/mtd/nand/nand_util.c,定位到483行,在nand_write_skip_bad函数中添加代码,修改如下: int nand_write_skip_bad(nand_info_t *nand, loff_t offset, size_t *length, u_char *buffer) { int rval; size_t left_to_write = *length; size_t len_incl_bad; u_char *p_buffer = buffer; #if defined(CONFIG_MTD_NAND_YAFFS2) if(nand->rw_oob==1) { size_t oobsize = nand->oobsize; size_t datasize = nand->writesize; int datapages = 0; if (((*length)%(nand->oobsize+nand->writesize)) != 0) { printf ("Attempt to write error length data!\n"); return -EINVAL; } datapages = *length/(datasize+oobsize); *length = datapages*datasize; left_to_write = *length; } #endif /* Reject writes, which are not page aligned */ if ((offset & (nand->writesize - 1)) != 0 || (*length & (nand->writesize - 1)) != 0) { printf ("Attempt to write non page aligned data\n"); return -EINVAL; } len_incl_bad = get_len_incl_bad (nand, offset, *length); if ((offset + len_incl_bad) >= nand->size) { printf ("Attempt to write outside the flash area\n"); return -EINVAL; } #if !defined(CONFIG_MTD_NAND_YAFFS2)//add yaffs2 file system support if (len_incl_bad == *length) { rval = nand_write (nand, offset, length, buffer); if (rval != 0) printf ("NAND write to offset %llx failed %d\n", offset, rval); return rval; } #endif while (left_to_write > 0) { size_t block_offset = offset & (nand->erasesize - 1); size_t write_size; WATCHDOG_RESET (); if (nand_block_isbad (nand, offset & ~(nand->erasesize - 1))) { printf ("Skip bad block 0x%08llx\n", offset & ~(nand->erasesize - 1)); offset += nand->erasesize - block_offset; continue; } #if defined(CONFIG_MTD_NAND_YAFFS2) //add yaffs2 file system support if(nand->skipfirstblk==1) { nand->skipfirstblk=0; printf ("Skip the first good block %llx\n", offset & ~(nand->erasesize - 1)); offset += nand->erasesize - block_offset; continue; } #endif if (left_to_write < (nand->erasesize - block_offset)) write_size = left_to_write; else write_size = nand->erasesize - block_offset; printf("\rWriting at 0x%llx -- ",offset); //add yaffs2 file system support rval = nand_write (nand, offset, &write_size, p_buffer); if (rval != 0) { printf ("NAND write to offset %llx failed %d\n", offset, rval); *length -= left_to_write; return rval; } left_to_write -= write_size; printf("%d%% is complete.",100-(left_to_write/(*length/100)));/*Thanks for hugerat's code*/ offset += write_size; #if defined(CONFIG_MTD_NAND_YAFFS2) /*Thanks for hugerat's code*/ if(nand->rw_oob==1) { p_buffer += write_size+(write_size/nand->writesize*nand->oobsize); } else { p_buffer += write_size; } #else p_buffer += write_size; #endif } return 0; } (4)在第三步的nand_write_skip_bad函数中我们看到又对nand_write函数进行了访问,所以这一步是到nand_write函数中添加对yaffs2的支持。 打开/drivers/mtd/nand/nand_base.c,定位到1961行,修改如下: static int nand_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const uint8_t *buf) { struct nand_chip *chip = mtd->priv; int ret; #if defined(CONFIG_MTD_NAND_YAFFS2) /*Thanks for hugerat's code!*/ int oldopsmode = 0; if(mtd->rw_oob==1) { int i = 0; int datapages = 0; size_t oobsize = mtd->oobsize; size_t datasize = mtd->writesize; uint8_t oobtemp[oobsize]; datapages = len / (datasize); for(i = 0; i < (datapages); i++) { memcpy((void *)oobtemp, (void *)(buf + datasize * (i + 1)), oobsize); memmove((void *)(buf + datasize * (i + 1)), (void *)(buf + datasize * (i + 1) + oobsize), (datapages - (i + 1)) * (datasize) + (datapages - 1) * oobsize); memcpy((void *)(buf+(datapages) * (datasize + oobsize) - oobsize), (void *)(oobtemp), oobsize); } } #endif /* Do not allow reads past end of device */ if ((to + len) > mtd->size) return -EINVAL; if (!len) return 0; nand_get_device(chip, mtd, FL_WRITING); chip->ops.len = len; chip->ops.datbuf = (uint8_t *)buf; //chip->ops.oobbuf = NULL; #if defined(CONFIG_MTD_NAND_YAFFS2)//add yaffs2 file system support /*Thanks for hugerat's code!*/ if(mtd->rw_oob!=1) { chip->ops.oobbuf = NULL; } else { chip->ops.oobbuf = (uint8_t *)(buf+len); chip->ops.ooblen = mtd->oobsize; oldopsmode = chip->ops.mode; chip->ops.mode = MTD_OOB_RAW; } #else chip->ops.oobbuf = NULL; #endif ret = nand_do_write_ops(mtd, to, &chip->ops); *retlen = chip->ops.retlen; nand_release_device(mtd); #if defined(CONFIG_MTD_NAND_YAFFS2)//add yaffs2 file system support /*Thanks for hugerat's code!*/ chip->ops.mode = oldopsmode; #endif return ret; } 【2】在mini2440.h里添加yaffs2相关宏定义 打开include/configs/mini2440.h,定位到98行附近,加入下列代码: /* * Command line configuration. */ #include <config_cmd_default.h> #define CONFIG_CMD_CACHE #define CONFIG_CMD_DATE #define CONFIG_CMD_ELF #define CONFIG_CMD_NAND #define CONFIG_CMD_JFFS2 /* JFFS2 Support*/ ... ... 在文件末尾处加入下列代码: /*----------------------------------------------------------------------- * NAND flash settings */ #if defined(CONFIG_CMD_NAND) #define CONFIG_NAND_S3C2410 #define CONFIG_SYS_NAND_BASE 0x4E000000 #define CONFIG_SYS_MAX_NAND_DEVICE 1 /* Max number of NAND devices */ #define SECTORSIZE 512 #define SECTORSIZE_2K 2048 #define NAND_SECTOR_SIZE SECTORSIZE #define NAND_SECTOR_SIZE_2K SECTORSIZE_2K #define NAND_BLOCK_MASK 511 #define NAND_BLOCK_MASK_2K 2047 #define NAND_MAX_CHIPS 1 #define CONFIG_MTD_NAND_VERIFY_WRITE #define CONFIG_SYS_64BIT_VSPRINTF /* needed for nand_util.c */ #endif /* CONFIG_CMD_NAND */ #define CONFIG_JFFS2_NAND 1 //#undef CONFIG_JFFS2_CMDLINE #define CONFIG_JFFS2_DEV "nand0" #define CONFIG_JFFS2_PART_SIZE 0x480000 #define CONFIG_JFFS2_PART_OFFSET 0x80000 #define CONFIG_JFFS2_CMDLINE 1 #define MTDIDS_DEFAULT "nand0=nandflash0" #define MTDPARTS_DEFAULT "mtdparts=nandflash0:384k(bootloader)," \ "128k(params)," \ "5m(kernel)," \ "-(root)" #define CONFIG_MTD_NAND_YAFFS2 1 #define ENABLE_CMD_LOADB_X 1 5.2, 烧录yaffs2文件系统测试 重新编译后下载,nand方式启动,在u-boot的命令行输入nand help查看nand的命令,可以看到多了一个nand write[.yaffs2]的命令: [u-boot@MINI2440]# nand help nand - NAND sub-system Usage: nand info - show available NAND devices nand device [dev] - show or set current device nand read - addr off|partition size nand write - addr off|partition size read/write 'size' bytes starting at offset 'off' to/from memory address 'addr', skipping bad blocks. nand erase [clean] [off size] - erase 'size' bytes from offset 'off' (entire device if not specified) nand write[.yaffs2] - addr off|partition size - write `size' byte yaffs image starting at offset off' from memory address addr' (.yaffs2 for 512+16 NAND) nand bad - show bad blocks nand dump[.oob] off - dump page nand scrub - really clean NAND erasing bad blocks (UNSAFE) nand markbad off [...] - mark bad block(s) at offset (UNSAFE) nand biterr off - make a bit error at offset (UNSAFE) [u-boot@MINI2440]# 这个就是用来下载yaffs2文件系统到nand中的命令了。首先需要将友善官方提供的有关mini2440的yaffs2文件系统文件root_qtopia-128M.img复制到linux宿主机的/tftpboot目录下,然后执行: tf[u-boot@MINI2440]# tp 0x30000000 root_qtopia-128M.img Filename 'root_qtopia-128M.img'. Load address: 0x30000000 Loading: T ##########T T #####################################################T ##T T #T T T T ###### Retry count exceeded; starting again dm9000 i/o: 0x20000300, id: 0x90000a46 DM9000: running in 16 bit mode MAC: 12:34:56:78:9a:bc operating at 100M full duplex mode Using dm9000 device TFTP from server 10.1.0.128; our IP address is 10.1.0.129 Filename 'root_qtopia-128M.img'. Load address: 0x30000000 Loading: T ###T ###T T ######## 一直无休止循环,经网上搜索得知Uboot 端 tftp 程序传过来的Timeout参数不符合服务器端定义引起的,原文链接地址 Retry count exceeded; starting again 解决方法:tftp客户端传过来的timeout是7810,而服务器端定义的范围在1-255秒之间,不是服务器的问题,而是uboot中tftp参数设置的问题,参见TFTP Unsupported option(s) requested 问题详细分析及解决。 打开/net/net.c,定位到104行附近,修改如下: #if defined(CONFIG_CMD_NET) DECLARE_GLOBAL_DATA_PTR; #ifndef CONFIG_ARP_TIMEOUT # define ARP_TIMEOUT 10000UL*CONFIG_SYS_HZ/1000 //5000UL /* Milliseconds before trying ARP again */ #else # define ARP_TIMEOUT CONFIG_ARP_TIMEOUT #endif 定位到573行附近,修改如下: #ifndef CONFIG_NET_MULTI //NetSetTimeout (10000UL, startAgainTimeout); NetSetTimeout (10000UL*CONFIG_SYS_HZ/1000, startAgainTimeout); NetSetHandler (startAgainHandler); #else /* !CONFIG_NET_MULTI*/ 定位到585行附近,修改如下: eth_init (gd->bd); if (NetRestartWrap) { NetRestartWrap = 0; if (NetDevExists && !once) { //NetSetTimeout (10000UL, startAgainTimeout); NetSetTimeout (10000UL*CONFIG_SYS_HZ/1000, startAgainTimeout); NetSetHandler (startAgainHandler); } else { NetState = NETLOOP_FAIL; } 定位到779行附近,修改如下: #define CDP_SYSOBJECT_TLV 0x0015 #define CDP_MANAGEMENT_ADDRESS_TLV 0x0016 #define CDP_TIMEOUT (250UL*CONFIG_SYS_HZ/1000) //250UL /* one packet every 250ms */ static int CDPSeq; static int CDPOK; 打开/net/tftp.c,定位到16行,修改如下: #define TIMEOUT 60000UL //5000UL /* Millisecs to timeout for lost pkt */ 然后重新编译后下载测试: [u-boot@MINI2440]# tftp 0x30000000 root_qtopia-128M.img dm9000 i/o: 0x20000300, id: 0x90000a46 DM9000: running in 16 bit mode MAC: 12:34:56:78:9a:bc operating at 100M full duplex mode Using dm9000 device TFTP from server 10.1.0.128; our IP address is 10.1.0.129 Filename 'root_qtopia-128M.img'. Load address: 0x30000000 Loading: T T T T T T T T T T Retry count exceeded; starting again dm9000 i/o: 0x20000300, id: 0x90000a46 DM9000: running in 16 bit mode MAC: 12:34:56:78:9a:bc operating at 100M full duplex mode Using dm9000 device TFTP from server 10.1.0.128; our IP address is 10.1.0.129 Filename 'root_qtopia-128M.img'. Load address: 0x30000000 Loading: ################################################################# ################################################################# ... ... ################################################################# #################### done Bytes transferred = 58487616 (37c7340 hex) [u-boot@MINI2440]# 在yaffs2文件系统镜像下载到内存后: [u-boot@MINI2440]# nand erase 0 0x40000 NAND erase: device 0 offset 0x0, size 0x40000 Erasing at 0x2000000000004 -- 0% complete. OK [u-boot@MINI2440]# nand write 0x30000000 0 0x40000 NAND write: device 0 offset 0x0, size 0x40000 Writing at 0x2000000020000 -- 100% is complete. 262144 bytes written: OK [u-boot@MINI2440]# 可以看到,yaffs2文件系统烧录成功。下一步需要加载内核来挂载yaffs2文件系统。 接下来将进入u-boot的第六阶段,为u-boot-2009.08 增加引导内核功能。
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