linux内核的加载地址和入口地址-行健天下ing-ChinaUnix博客

编译完内核之后，会产生zImage,而把它直接导入0x30008000，会出现 Bad Magic Number.

查明是需要将内核加一个0x40大小的头,由mkimage工具来添加.mkimage在编译u-boot时在u-boot-1.1.6/tools下生成,可以为编译的内核添加头信息的.在bootm命令中会解析这个头,获得参数.zImage在编译内核时，在arch/arm/boot目录下生成。我们需要把zImage用mkimage工具处理一下。

mkimage 参数的意义如下：

-A == set architecture to 'arch'

-O == set operating system to 'os'

-T == set image type to 'type'

-C == set compression type 'comp'

-a == set load address to 'addr' (hex)

-e == set entry point to 'ep' (hex)

-n == set image name to 'name'

-d == use image data from 'datafile'

-x == set XIP (execute in place)

首先可以把zImage 拷贝到 u-boot-1.1.6/tools目录下，在此目录下，执行如下命令：

./mkimage -n 'linux-2.6.26' -A arm -O linux -T kernel -C none -a 0x30007fc0 -e 0x30008000 -d zImage uImage

输出信息如下：

Image Name: linux-2.6.26

Created: Tue Jul 28 18:50:26 2009

Image Type: ARM Linux Kernel Image (uncompressed)

Data Size: 1655648 Bytes = 1616.84 kB = 1.58 MB

Load Address: 0x30007FC0

Entry Point: 0x30008000

可以看出加载地址是 0x30007fc0,而入口地址是 0x30008000.

GEC2410 # tftp 30008000 uImage

TFTP from server 192.168.0.50; our IP address is 192.168.0.100

Filename 'uImage'.

Load address: 0x30008000

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

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

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

done

Bytes transferred = 1655712 (1943a0 hex)

GEC2410 # bootm 30008000

## Booting image at 30008000 ...

Image Name: linux-2.6.26

Created: 2009-07-28 10:50:26 UTC

Image Type: ARM Linux Kernel Image (uncompressed)

Data Size: 1655648 Bytes = 1.6 MB

Load Address: 30007fc0

Entry Point: 30008000

Verifying Checksum ... OK

Starting kernel ...(卡死在这儿了)

GEC2410 # tftp 30008000 uImage

TFTP from server 192.168.0.50; our IP address is 192.168.0.100

Filename 'uImage'.

Load address: 0x30008000

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

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

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

done

Bytes transferred = 1655712 (1943a0 hex)

GEC2410 # bootm 30007fc0

## Booting image at 30007fc0 ...

Bad Magic Number

GEC2410 # tftp 30007fc0 uImage

TFTP from server 192.168.0.50; our IP address is 192.168.0.100

Filename 'uImage'.

Load address: 0x30007fc0

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

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

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

done

Bytes transferred = 1655712 (1943a0 hex)

GEC2410 # bootm 30008000

## Booting image at 30008000 ...

Bad Magic Number

GEC2410 #

GEC2410 # tftp 0x30007fc0 uImage

TFTP from server 192.168.0.50; our IP address is 192.168.0.100

Filename 'uImage'.

Load address: 0x30007fc0

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

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

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

done

Bytes transferred = 1655712 (1943a0 hex)

GEC2410 # bootm 30007fc0

## Booting image at 30007fc0 ...

Image Name: linux-2.6.26

Created: 2009-07-28 10:50:26 UTC

Image Type: ARM Linux Kernel Image (uncompressed)

Data Size: 1655648 Bytes = 1.6 MB

Load Address: 30007fc0

Entry Point: 30008000

Verifying Checksum ... OK

XIP Kernel Image ... OK

Starting kernel ...

Uncompressing Linux............................................................................................................ done, booting the kernel.

………………….

(一大堆信息)

从上面可以看出，tftp下载的地址和bootm引导的地址是同一个地址，且是mkimage的参数 -a 的地址，即加载地址，而不是入口地址。

./mkimage -n 'linux-2.6.26' -A arm -O linux -T kernel -C none -a 0x30008000 -e 0x30008000 -d zImage uImage

Created: Tue Jul 28 19:21:15 2009

Image Type: ARM Linux Kernel Image (uncompressed)

Data Size: 1655648 Bytes = 1616.84 kB = 1.58 MB

Load Address: 0x30008000

Entry Point: 0x30008000

入口地址和加载地址一样的时候，

我在做这个尝试的时候，导致开发板重启……。

现在能正确引导内核啦，但是GEC2410的网卡芯片是CS8900A的芯片，要能正确的启动Linux系统，还必须添加CS8900A的驱动……