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yaffs具有不易失特性，在嵌入式系统中占有一席之地。 下面介绍如何在内核中添加对yaffs文件系统的支持，以及如何使用yaffs根文件系统启动linux系统。 add yaffs fs support in kernel and make yaffs rootfs
1 preparation
adownload yaffs source code and add it in your kernel source code in fsyaffs
httphusaberg.toby-churchill.comballoonlinux-2.6.8.1-tcl1fsyaffs
modify fsKconfig , add following option
config YAFFS_FS
tristate YAFFS filesystem support
depends on MTD_NAND
help
If you want YAFFS support on NAND flash devices you either need to have
NAND mtd support or customise the NAND interface.
YAFFS is a journaling filesystem tailored to the idiosyncrasies of
NAND flash memory. For further details see
YAFFS is also available as a module ( = code which can be
i nserted in and removed from the running kernel whenever you want).
The module is called nfsd. If you want to compile it as a module,
say M here and read . If unsure,
say N. config CRAMFS
tristate Compressed ROM file system support (cramfs)
... bdownload nandwrite.c , nanddump.c and eraseall.c from
ftp166.111.68.183pubembeduclinuxsoftuClinux-distusermtd-utils
compile them.
arm-linux-gcc nandwrite.c -o nandwrite
arm-linux-gcc nanddump.c -o nanddump
arm-linux-gcc eraseall.c -o eraseall cmodify devs.c to add a new partition in mtd (optional) , the yaffs will be in theyaffs partition
like
{
name user,
size 0x00c00000,
offset 0x00400000,
mask_flags MTD_WRITEABLE,
}, {
name yaffs,
size 0x02000000,
offset 0x01000000,
mask_flags MTD_WRITEABLE,
}
......
nr_partitions 6 , note if you do so, the bootloader(vivi)'s partition table should be changed too.(part deladd)
2 compile your kernel
3 make yaffs partition
amake yaffs image
download mkyaffsimage from httphusaberg.toby-churchill.comballoonreleasesv0.7roots
put your files in temp directory
.mkyaffsimage temp temp.yaffs
bwrite image to flash
.eraseall devmtd5
.nandwrite devmtd5 temp.yaffs 16384
noteI've read the source code of yaffs, and find that the first block is not scaned when the super block is loaded. So your image should be write to the second block.
Each block is 51232 (BYTESPERCHUNKCHUNKSPERBLOCK) bytes.
4 Good luck..... 在嵌入式系统中应用yaffs。。。- -
首先download一个yaffs的源程序包。。。 解压，进入yaffs/utils目录，编辑Makefile为自己相应的资源目录 make mkyaffs make mkyaffsimage 产生两个bin工具。。。 进入目标板程序， mkyaffsimage是用来产生img用的，例如 ./mkyaffsimage /dir filename.img 就会产生一个filename.img的文件，再 ./mkyaffs /dev/mtd1 filename.img， 把mtd1设备mount到相应的目录，就可以了。
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