嵌入式Linux启动过程中的问题积累

1.Bad Magic Number

## Booting image at 33000000 ...

Bad Magic Number

OMAP5912 OSK #（tftp下载好kernel的uImage后就停止在这，不能启动kernel）

问题原因：启动参数设置错误,0x30000000处不可以执行。

有的开发板sdram不是在0x33000000，所以不能把kernel uImage下载到0x33000000中运行。如我之前的bootcmd参数为:setenv bootcmd tftpboot 33000000 uImage/; bootm 33000000。但板子Omap5912的sdram地址在0x100000000，将参数改为setenv bootcmd tftpboot 10000000 uImage/; bootm 10000000后便可以启动kernel了。

2.启动停止在"Starting kernel ..."

TFTP from server 192.168.167.170; our IP address is 192.168.167.15

Filename uImage

Load address: 0x10000000

Loading: #################################################################

#################################################################

done

Bytes transferred = 2025908 (1ee9b4 hex)

## Booting image at 10000000 ...

Image Name:Linux-2.6.18-mh8_pro500-versatil

Image Type:ARM Linux Kernel Image (uncompressed)

Data Size:2025844 Bytes =1.9 MB

Load Address: 30008000

Entry Point:30008000

Verifying Checksum ... OK

OK

Starting kernel ...（卡在这里）

问题原因：多半是kernel没编译成功。

确认configure参数是否配置正确，是否选择了正确的目标编译平台，如smdk2410等。

3.不能启动kernel

Starting kernel ...

Uncompressing Linux.........................................................

.................... done, booting the kernel.

问题原因：可能是Bootargs参数设置错误,确认bootargs设置是否正确。

4.不能挂载nfs

eth0: link up

IP-Config: Complete:

device=eth0, addr=192.168.167.15, mask=255.255.255.0, gw=192.168.167.254,

host=192.168.167.15, domain=, nis-domain=(none),

bootserver=192.168.167.170, rootserver=192.168.167.170, rootpath=

Looking upportofRPC100003/2 on 192.168.167.170

Root-NFS: Unable to get nfsd port number from server, using default

Looking upportofRPC100005/1 on 192.168.167.170

Root-NFS: Unable to get mountd port number from server, using default

mount: server 192.168.167.170 not responding, timed out

Root-NFS: Server returned error -5 while mounting /work/nfs/rootfs_bluetooth_omap

VFS: Unable to mount root fs via NFS, trying floppy.

VFS: Cannot open root device "nfs" or unknown-block(2,0)

Please append a correct "root=" boot option

Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(2,0)

问题原因：这种情况通常是nfs配置问题。

确认uboot的bootargs参数里和nfs相关的ip地址信息设置是否正确，以及Host机/etc/exports配置无误，重起nfs服务,重新尝试连接。另外还需要注意bootargs内console和mem两个参数的设置。kernel2.6后console最好设置为ttySAC0，mem也要根据开发板实际情况设置正确。

5.文件系统不能启动问题

eth0: link up

IP-Config: Complete:

device=eth0, addr=192.168.167.15, mask=255.255.255.0, gw=192.168.167.254,

host=192.168.167.15, domain=, nis-domain=(none),

bootserver=192.168.167.170, rootserver=192.168.167.170, rootpath=

Looking upportofRPC100003/2 on 192.168.167.170

Looking upportofRPC100005/1 on 192.168.167.170

VFS: Mounted root (nfs filesystem).

Freeing init memory: 128K

/sbin/initKernel panic - not syncing: Attempted to kill init!

问题原因：制作的文件系统缺少运行busybox所需的libcrypt.so库，新版本会有缺库提示，老版本(1.60)没有。

注：运行一个busybox文件系统至少需要如下几个库：

ld-linux.so.x

libc.so.6

libcrypt.so.x

较新版本的busybox可能还需要

libm.so.6

libgcc_s.so.x

(x为版本号）

6.文件系统不能启动问题2

eth0: link up

IP-Config: Complete:

device=eth0, addr=192.168.167.15, mask=255.255.255.0, gw=192.168.167.254,

host=192.168.167.15, domain=, nis-domain=(none),

bootserver=192.168.167.170, rootserver=192.168.167.170, rootpath=

Looking upportofRPC100003/2 on 192.168.167.170

Looking upportofRPC100005/1 on 192.168.167.170

VFS: Mounted root (nfs filesystem).

Freeing init memory: 128K

Kernel panic -