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下载新编译的内核出现：No filesystem could mount root, tried: ext3 ext2 cramfs vfat msdos iso9660 romfs ernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(31,3)
Backtrace:
[] (dump_backtrace+0x0/0x10c) from [] (dump_stack+0x18/0x1c)
r6:c38a9000 r5:ffffffea r4:c381df2c
Backtrace:
[] (dump_backtrace+0x0/0x10c) from [] (dump_stack+0x18/0x1c)
r6:c38a9000 r5:ffffffea r4:c381df2c
原因是：（1）内核的NAND 没有分区 （2）没有对YAFFS的支持 （3）uboot参数配置问题（是jffs2启动，还是yaffs启动）
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uboot参数配置问题：（是jffs2启动，还是yaffs启动）
在uboot 命令行输入 print ,若参数里含 rootfstype=jffs2，则是jffs2启动；不含 rootfstype=jffs2，则是yaffs启动
SMDK2410 # print
baudrate=115200
bootargs=console=ttySAC0,115200 root=/dev/mtdblock3 rootfstype=jffs2
bootcmd=nand read.jffs2 0x30007FC0 kernel; bootm 0x30007FC0
bootdelay=2
ethact=dm9000
ethaddr=08:00:3e:26:0a:5b
fileaddr=30000000
filesize=3B8BA8
gatewayip=192.168.1.1
ipaddr=192.168.1.17
machid=16a
mtddevname=u-boot
mtddevnum=0
mtdids=nand0=jz2440-0
mtdparts=mtdparts=jz2440-0:256k(u-boot),128k(params),2m(kernel),-(rootfs)
netmask=255.255.255.0
partition=nand0,0
serverip=192.168.1.103
stderr=serial
stdin=serial
stdout=serial
Environment size: 557/131068 bytes
baudrate=115200
bootargs=console=ttySAC0,115200 root=/dev/mtdblock3 rootfstype=jffs2
bootcmd=nand read.jffs2 0x30007FC0 kernel; bootm 0x30007FC0
bootdelay=2
ethact=dm9000
ethaddr=08:00:3e:26:0a:5b
fileaddr=30000000
filesize=3B8BA8
gatewayip=192.168.1.1
ipaddr=192.168.1.17
machid=16a
mtddevname=u-boot
mtddevnum=0
mtdids=nand0=jz2440-0
mtdparts=mtdparts=jz2440-0:256k(u-boot),128k(params),2m(kernel),-(rootfs)
netmask=255.255.255.0
partition=nand0,0
serverip=192.168.1.103
stderr=serial
stdin=serial
stdout=serial
Environment size: 557/131068 bytes