Linux内核启动出错can't get kernel image

原文链接：https://blog.csdn.net/zhengqijun_/article/details/71908896

主机环境：RHEL6.5

编译器：arm-linux-gcc 4.3.2

开发板：mini2440

u-boot：2010.03

内核：Linux

1、下载uImage到0x30008000

[u-boot@MINI2440]# tftp 30008000 uImage
dm9000 i/o: 0x20000300, id: 0x90000a46 
DM9000: running in 16 bit mode
MAC: 08:08:11:18:12:27
operating at 100M full duplex mode
Using dm9000 device
TFTP from server 192.168.1.121; our IP address is 192.168.1.230
Filename 'uImage'.
Load address: 0x30008000
Loading: T #################################################################
         #################################################################
         ###############################
done
Bytes transferred = 2352280 (23e498 hex)

2、使用md命令查看内存数据

使用uboot 中的md 命令查看内存数据

[u-boot@MINI2440]# md 0x30008000
30008000: 56190527 df76f429 50e71659 58e42300    '..V).v.Y..P.#.X
30008010: 00800030 40800030 44288445 00020205    0...0..@E.(D....
30008020: 756e694c 2e322d78 32332e36 462d322e    Linux-2.6.32.2-F
30008030: 6e656972 41796c64 00004d52 00000000    riendlyARM......
30008040: e1a00000 e1a00000 e1a00000 e1a00000    ................
30008050: e1a00000 e1a00000 e1a00000 e1a00000    ................
30008060: ea000002 016f2818 00000000 0023e458    .....(o.....X.#.
30008070: e1a07001 e1a08002 e10f2000 e3120003    .p....... ......
30008080: 1a000001 e3a00017 ef123456 e10f2000    ........V4... ..
30008090: e38220c0 e121f002 00000000 00000000    . ....!.........
300080a0: e28f00d4 e890307e e0500001 0a00000a    ....~0....P.....
300080b0: e0855000 e0866000 e08cc000 e0822000    .P...`....... ..
300080c0: e0833000 e08dd000 e5961000 e0811000    .0..............
300080d0: e4861004 e156000c 3afffffa e3a00000    ......V....:....
300080e0: e4820004 e4820004 e4820004 e4820004    ................
300080f0: e1520003 3afffff9 eb000028 e1a0100d    ..R....:(.......

3、直接从flash的0x30008000处启动
bootm 0x30008000

启动信息如下所示：

[u-boot@MINI2440]# bootm 0x30008000
## Booting kernel from Legacy Image at 30008000 ...
   Image Name:   Linux-2.6.32.2-FriendlyARM
   Created:      2017-05-13  11:00:32 UTC
   Image Type:   ARM Linux Kernel Image (uncompressed)
   Data Size:    2352216 Bytes =  2.2 MB
   Load Address: 30008000
   Entry Point:  30008040
   Verifying Checksum ... OK
   XIP Kernel Image ... OK
OK

Starting kernel …

Uncompressing Linux…
… done, booting the kernel.

Please press Enter to activate this console.

说明Linux内核直接从flash启动是没有问题的！（Linux内核的中间启动信息省略。）

4、关机重启
从nand启动出错，出错信息为

NAND read: device 0 offset 0x60000, size 0x400000
 4194304 bytes read: OK

Wrong Image Format for bootm command
ERROR: can’t get kernel image!

NAND明明读取成功，却找不到kernel image。那下面来看看是不是读取的数据有问题。

5、使用md命令查看0x30008000处的数据

使用uboot 中的md 命令查看内存数据

[u-boot@MINI2440]# md 0x30008000                        
30008000: be56bfb3 746f6f62 73677261 696f6e3d    ..V.bootargs=noi
30008010: 7274696e 6f722064 2f3d746f 2f766564    nitrd root=/dev/
30008020: 2073666e 6e207772 6f727366 313d746f    nfs rw nfsroot=1
30008030: 312e3239 312e3836 3132312e 666e2f3a    92.168.1.121:/nf
30008040: 6f722f73 7366746f 3d706920 2e323931    s/rootfs ip=192.
30008050: 2e383631 33322e31 39313a30 36312e32    168.1.230:192.16
30008060: 2e312e38 3a313231 2e323931 2e383631    8.1.121:192.168.
30008070: 3a312e31 2e353532 2e353532 2e353532    1.1:255.255.255.
30008080: 6f632030 6c6f736e 74743d65 43415379    0 console=ttySAC
30008090: 31312c30 30303235 696e6920 6c2f3d74    0,115200 init=/l
300080a0: 78756e69 6d206372 363d6d65 62004d34    inuxrc mem=64M.b
300080b0: 63746f6f 6e3d646d 20646e61 64616572    ootcmd=nand read
300080c0: 33783020 38303030 20303030 30367830     0x30008000 0x60
300080d0: 20303030 30303034 203b3030 746f6f62    000 400000; boot
300080e0: 3033206d 30383030 62003030 64746f6f    m 30008000.bootd
300080f0: 79616c65 6200333d 72647561 3d657461    elay=3.baudrate=

发现保存的是uboot 的环境变量，所以导致Linux 内核启动出错！
发现在0x30008000处的flash 果然不是正确的内核启动数据，所以uboot 才会提示找不到内核！
我首先猜想是不是nand write/read 命令有问题，没有将内核数据写入到NAND中。

6、下面我使用uboot 的mw 命令来进行验证
a、先将flash从0x30008000处开始写入0x1000个1。

[u-boot@MINI2440]# mw 30008000 1 1000  
[u-boot@MINI2440]# md 30008000 
30008000: 00000001 00000001 00000001 00000001    ................
30008010: 00000001 00000001 00000001 00000001    ................
30008020: 00000001 00000001 00000001 00000001    ................
30008030: 00000001 00000001 00000001 00000001    ................
30008040: 00000001 00000001 00000001 00000001    ................
30008050: 00000001 00000001 00000001 00000001    ................
30008060: 00000001 00000001 00000001 00000001    ................
30008070: 00000001 00000001 00000001 00000001    ................
30008080: 00000001 00000001 00000001 00000001    ................
30008090: 00000001 00000001 00000001 00000001    ................
300080a0: 00000001 00000001 00000001 00000001    ................
300080b0: 00000001 00000001 00000001 00000001    ................
300080c0: 00000001 00000001 00000001 00000001    ................
300080d0: 00000001 00000001 00000001 00000001    ................
300080e0: 00000001 00000001 00000001 00000001    ................
300080f0: 00000001 00000001 00000001 00000001    ................

b、写入NAND中。

先进行擦除nand

[u-boot@MINI2440]# nand erase 60000 1000

NAND erase: device 0 offset 0x60000, size 0x1000
Warning: Erase size 0x00001000 smaller than one erase block 0x00020000
Erasing 0x00020000 instead
Erasing at 0x6000000000002 – 0% complete.
OK

然后写入nand

[u-boot@MINI2440]# nand write 0x30008000 60000 1000

NAND write: device 0 offset 0x60000, size 0x1000
Writing at 0x6000000020000 – 100% is complete. 4096 bytes written: OKc、将0x30008000处的数据清0

[u-boot@MINI2440]# mw 0x30008000 0 1000

[u-boot@MINI2440]# md 30008000                     

30008000: 00000000 00000000 00000000 00000000    …

30008010: 00000000 00000000 00000000 00000000    …

30008020: 00000000 00000000 00000000 00000000    …

30008030: 00000000 00000000 00000000 00000000    …

30008040: 00000000 00000000 00000000 00000000    …

30008050: 00000000 00000000 00000000 00000000    …

30008060: 00000000 00000000 00000000 00000000    …

30008070: 00000000 00000000 00000000 00000000    …

30008080: 00000000 00000000 00000000 00000000    …

30008090: 00000000 00000000 00000000 00000000    …

300080a0: 00000000 00000000 00000000 00000000    …

300080b0: 00000000 00000000 00000000 00000000    …

300080c0: 00000000 00000000 00000000 00000000    …

300080d0: 00000000 00000000 00000000 00000000    …

300080e0: 00000000 00000000 00000000 00000000    …

300080f0: 00000000 00000000 00000000 00000000    …

d、读取NAND处的数据到flash中进行验证

[u-boot@MINI2440]# nand read 0x30008000 0x60000 1000

NAND read: device 0 offset 0x60000, size 0x1000
4096 bytes read: OK
[u-boot@MINI2440]# md 30008000
30008000: 00000001 00000001 00000001 00000001 …
30008010: 00000001 00000001 00000001 00000001 …
30008020: 00000001 00000001 00000001 00000001 …
30008030: 00000001 00000001 00000001 00000001 …
30008040: 00000001 00000001 00000001 00000001 …
30008050: 00000001 00000001 00000001 00000001 …
30008060: 00000001 00000001 00000001 00000001 …
30008070: 00000001 00000001 00000001 00000001 …
30008080: 00000001 00000001 00000001 00000001 …
30008090: 00000001 00000001 00000001 00000001 …
300080a0: 00000001 00000001 00000001 00000001 …
300080b0: 00000001 00000001 00000001 00000001 …
300080c0: 00000001 00000001 00000001 00000001 …
300080d0: 00000001 00000001 00000001 00000001 …
300080e0: 00000001 00000001 00000001 00000001 …
300080f0: 00000001 00000001 00000001 00000001 …写入的数据和读取的数据一致，说明nand write/read命令的功能正常！

仔细查看刚启动的0x30008000处的数据，发现保存的是uboot 的环境变量，所以猜测主要原因可能在于uboot 环境变量的保存位置不对。

注意：这里Linux内核启动失败是因为环境变量覆盖内核数据，导致内核无法正确启动！

uboot 环境变量的保存配置文件在uboot 的include/configs/mini2440.h 文件中。

#define CONFIG_ENV_OFFSET 0X60000    // 决定uboot环境变量的保存位置。

因为0x60000是Linux内核的分区位置，所以每次加载Linux内核的时候，就会出现找不到Kernel image！

7、解决方法
将#define CONFIG_ENV_OFFSET 0X60000 改为#define CONFIG_ENV_OFFSET 0X40000后，在重新下载到开发板中运行即可。

8、重新下载Linux内核镜像后，写入nand进行重启。

tftp 0x30008000 uImage
nand erase 0x00060000 0x00500000
nand write 0x30008000 0x00060000 400000

然后重启开发板出现的Linux 打印的启动信息如下所示：

UBoot 2010.03 (5月 13 2017 - 20:25:21)

modified by tekkamanninja ([email protected])
Love Linux forever!!

I2C: ready
DRAM: 64 MB
Flash: 2 MB
NAND: 256 MiB
In: serial
Out: serial
Err: serial
USB slave is enable!
Net: dm9000
Hit any key to stop autoboot: 0

NAND read: device 0 offset 0x60000, size 0x400000
4194304 bytes read: OK

Booting kernel from Legacy Image at 30008000 …

Image Name: Linux-2.6.32.2-FriendlyARM
Created: 2017-05-13 11:00:32 UTC
Image Type: ARM Linux Kernel Image (uncompressed)
Data Size: 2352216 Bytes = 2.2 MB
Load Address: 30008000
Entry Point: 30008040
Verifying Checksum … OK
XIP Kernel Image … OK
OK

Starting kernel …

Uncompressing Linux…
… done, booting the kernel.
[ 0.000000] Linux version 2.6.32.2-FriendlyARM (root@codeMonkey) (gcc version 4.3.2) #4 Sat May 13 19:00:29 CST 2017
[    0.000000] CPU: ARM920T [41129200] revision 0 (ARMv4T), cr=c0007177
[    0.000000] CPU: VIVT data cache, VIVT instruction cache
[    0.000000] Machine: FriendlyARM Mini2440 development board
[    0.000000] Memory policy: ECC disabled, Data cache writeback
[    0.000000] CPU S3C2440A (id 0x32440001)
[    0.000000] S3C24XX Clocks, © 2004 Simtec Electronics
[    0.000000] S3C244X: core 405.000 MHz, memory 101.250 MHz, peripheral 50.625 MHz

Please press Enter to activate this console. 

（Linux内核中间启动过程信息省略！）