四、U-boot的使用（四）

下载与烧写

使用U-boot将映像文件烧写到板上的Flash，一般步骤是：
（1）通过网络、串口、U盘、SD卡等方式将文件传输到SDRAM；
（2）使用Nand Flash或Nor Flash相关的读写命令将SDRAM中的数据烧入Flash。

下面是烧写范例：
如果使用 SD卡和U盘形式更新U-boot，那么首先SD卡和U盘中必须有FAT32文件系统，并在里面存放了u-boot.bin 文件。
1) 通过SD卡烧入Nand Flash：

[u-boot@MINI2440]# mmc init

mmc: Probing for SDHC ...

mmc: SD 2.0 or later card found

trying to detect SD Card...

Manufacturer:       0x00, OEM "Product name:       "     ", revision 0.0

Serial number:      7864775

Manufacturing date: 11/2006

CRC:                0x4f, b0 = 1

READ_BL_LEN=6, C_SIZE_MULT=7, C_SIZE=4095

size = 0

SD Card detected RCA: 0x2 type: SD

mmc1 is available

[u-boot@MINI2440]# fatload mmc 1 0x30008000 u-boot.bin

reading u-boot.bin

 

256220 bytes read

[u-boot@MINI2440]# nand erase 0 0x40000

 

NAND erase: device 0 offset 0x0, size 0x40000

Erasing at 0x2000000000004 --   0% complete.

OK

[u-boot@MINI2440]# nand write 0x30008000 0 0x40000

 

NAND write: device 0 offset 0x0, size 0x40000

Writing at 0x2000000020000 -- 100% is complete. 262144 bytes written: OK

2) 通过U盘烧入Nor Flash：

[u-boot@MINI2440]# usb start

(Re)start USB...

USB:   scanning bus for devices... 2 USB Device(s) found

       scanning bus for storage devices... 1 Storage Device(s) found

[u-boot@MINI2440]# usb storage

  Device 0: Vendor: Kingston Rev: PMAP Prod: DT 101 II      

            Type: Removable Hard Disk

            Capacity: 3875.0 MB = 3.7 GB (7936000 x 512)

[u-boot@MINI2440]# usb part 0

print_part of 0

 

Partition Map for USB device 0  --   Partition Type: DOS

 

Partition     Start Sector     Num Sectors     Type

    4                     63         7935937    c

 [u-boot@MINI2440]# fatload usb 0:4 0x30008000 u-boot.bin

reading u-boot.bin

........................

 

256220 bytes read

[u-boot@MINI2440]# protect off all

Un-Protect Flash Bank # 1

[u-boot@MINI2440]# erase 0x0 0x3ffff

Erasing sector  0 ... ok.

Erasing sector  1 ... ok.

Erasing sector  2 ... ok.

Erasing sector  3 ... ok.

Erased 4 sectors

[u-boot@MINI2440]# cp.b 0x30008000 0x0  0x3ffff

Copy to Flash... done

3) 通过TFTP服务烧入Nand Flash：

[u-boot@MINI2440]# tftpboot 30008000 192.168.1.100:u-boot.bin

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 192.168.1.100; our IP address is 192.168.1.101

Filename 'u-boot.bin'.

Load address: 0x30008000

Loading: T ##################

done

Bytes transferred = 256220 (3e8dc hex)

[u-boot@MINI2440]# nand erase 0 0x40000

NAND erase: device 0 offset 0x0, size 0x40000

Erasing at 0x2000000000004 --   0% complete.

OK

[u-boot@MINI2440]# nand write 0x30008000 0 0x40000

 

NAND write: device 0 offset 0x0, size 0x40000

Writing at 0x2000000020000 -- 100% is complete. 262144 bytes written: OK

4) 通过NFS 服务烧入Nand Flash：

 

[u-boot@MINI2440]# nfs 30008000 192.168.1.100:/home/tekkaman/development/share/u-boot.bin

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

File transfer via NFS from server 192.168.1.100; our IP address is 192.168.1.101

Filename '/home/tekkaman/development/share/u-boot.bin'.

Load address: 0x30008000

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

done

Bytes transferred = 256220 (3e8dc hex)

[u-boot@MINI2440]# nand erase 0 0x40000

NAND erase: device 0 offset 0x0, size 0x40000

Erasing at 0x2000000000004 --   0% complete.

OK

[u-boot@MINI2440]# nand write 0x30008000 0 0x40000

 

NAND write: device 0 offset 0x0, size 0x40000

Writing at 0x2000000020000 -- 100% is complete. 262144 bytes written: OK

---

内核引导

内核的引导步骤如下：
（1）用U-boot的mkimage工具处理内核映像zImage。
（2）通过网络、串口、U盘、SD卡等方式将处理过的内核映像传输到SDRAM的一定位置（一般使用0x30008000）
（3）然后使用”bootm"等内核引导命令来启动内核。

为什么要用U-boot的mkimage工具处理内核映像zImage？

因为在用bootm命令引导内核的时候，bootm需要读取一个64字节的文件头，来获取这个内核映象所针对的CPU体系结构、OS、加载到内存中的位置、在内存中入口点的位置以及映象名等等信息。这样bootm才能为OS设置好启动环境，并跳入内核映象的入口点。而mkimage就是添加这个文件头的专用工具。具体的实现请看U-boot中bootm的源码和mkimage的源码。

mkimage工具的使用：

 

参数说明：

-A 指定CPU的体系结构，可用值有：alpha、arm 、x86、ia64、mips、mips64、ppc 、s390、sh、sparc 、sparc64、m68k等

-O 指定操作系统类型，可用值有：openbsd、netbsd、freebsd、4_4bsd、linux、svr4、esix、solaris、irix、sco、dell、ncr、lynxos、vxworks、psos、qnx、u-boot、rtems、artos

-T 指定映象类型，可用值有：standalone、kernel、ramdisk、multi、firmware、script、filesystem

-C 指定映象压缩方式，可用值有：

none 不压缩(一般使用这个，因为zImage是已经被bzip2压缩过的自解压内核)

gzip 用gzip的压缩方式

bzip2 用bzip2的压缩方式

-a 指定映象在内存中的加载地址，映象下载到内存中时，要按照用mkimage制作映象时，这个参数所指定的地址值来下载

-e 指定映象运行的入口点地址，这个地址就是-a参数指定的值加上0x40（因为前面有个mkimage添加的0x40个字节的头）

-n 指定映象名

-d 指定制作映象的源文件

 

以下是制作内核映像的命令示例：

mkimage -n 'tekkaman' -A arm -O linux -T kernel -C none -a 0x30008000 -e 0x30008040 -d zImage zImage.img

 

以下是使用范例：
1) 通过SD卡引导内核：
首先SD卡中必须有FAT32文件系统，并在里面存放了处理过的内核映像文件。

[u-boot@MINI2440]# mmc init                 

mmc: Probing for SDHC ...

mmc: SD 2.0 or later card found

trying to detect SD Card...

Manufacturer:       0x00, OEM "Product name:       "     ", revision 0.0

Serial number:      7864775

Manufacturing date: 11/2006

CRC:                0x4f, b0 = 1

READ_BL_LEN=6, C_SIZE_MULT=7, C_SIZE=4095

size = 0

SD Card detected RCA: 0x2 type: SD

mmc1 is available

[u-boot@MINI2440]# fatload mmc 1 30008000 zImage.img

reading zImage.img

 

2277540 bytes read

[u-boot@MINI2440]# bootm 30008000

## Booting kernel from Legacy Image at 30008000 ...

   Image Name:   tekkaman

   Created:      2010-03-29  12:59:51 UTC

   Image Type:   ARM Linux Kernel Image (uncompressed)

   Data Size:    2277476 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.

Linux version 2.6.33.1 (tekkaman@MAGI-Linux) (gcc version 4.3.2 (crosstool-NG-1.6.1-tekkaman) ) #5 Mon Mar 29 20:58:50 CST 2010

CPU: ARM920T [41129200] revision 0 (ARMv4T), cr=c0007177

CPU: VIVT data cache, VIVT instruction cache

Machine: MINI2440

（略）

2) 通过TFTP服务引导内核:

[u-boot@MINI2440]# tftpboot 0x30008000 192.168.1.100:zImage.img

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 192.168.1.100; our IP address is 192.168.1.101

Filename 'zImage.img'.

Load address: 0x30008000

Loading: T #################################################################

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

        ##########################

done

Bytes transferred = 2277540 (22c0a4 hex)

[u-boot@MINI2440]# bootm 30008000

## Booting kernel from Legacy Image at 30008000 ...

   Image Name:   tekkaman

   Created:      2010-03-29  12:59:51 UTC

   Image Type:   ARM Linux Kernel Image (uncompressed)

   Data Size:    2277476 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.

Linux version 2.6.33.1 (tekkaman@MAGI-Linux) (gcc version 4.3.2 (crosstool-NG-1.6.1-tekkaman) ) #5 Mon Mar 29 20:58:50 CST 2010

CPU: ARM920T [41129200] revision 0 (ARMv4T), cr=c0007177

CPU: VIVT data cache, VIVT instruction cache

Machine: MINI2440

（略）

 

3) 通过NFS服务引导内核：

[u-boot@MINI2440]# nfs 30008000 192.168.1.100:/home/tekkaman/development/share/zImage.img

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

File transfer via NFS from server 192.168.1.100; our IP address is 192.168.1.101

Filename '/home/tekkaman/development/share/zImage.img'.

Load address: 0x30008000

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

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

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

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

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

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

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

done

Bytes transferred = 2277540 (22c0a4 hex)

[u-boot@MINI2440]# bootm 30008000

## Booting kernel from Legacy Image at 30008000 ...

   Image Name:   tekkaman

   Created:      2010-03-29  12:59:51 UTC

   Image Type:   ARM Linux Kernel Image (uncompressed)

   Data Size:    2277476 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.

Linux version 2.6.33.1 (tekkaman@MAGI-Linux) (gcc version 4.3.2 (crosstool-NG-1.6.1-tekkaman) ) #5 Mon Mar 29 20:58:50 CST 2010

CPU: ARM920T [41129200] revision 0 (ARMv4T), cr=c0007177

CPU: VIVT data cache, VIVT instruction cache

Machine: MINI2440

（略）

4) 通过Nand Flash引导内核：
   首先要将处理过的内核映像文件烧入Nand Flash的一定位置（由内核分区表决定）。以后每次启动时用Nand Flash的读取命令先将这个内核映像文件读到内存的一定位置（由制作内核映像时的-a参数决定），再使用bootm命令引导内核。

内核映像文件的烧入：

[u-boot@MINI2440]# nfs 30008000 192.168.1.100:/home/tekkaman/development/share/zImage.img

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

File transfer via NFS from server 192.168.1.100; our IP address is 192.168.1.101

Filename '/home/tekkaman/development/share/zImage.img'.

Load address: 0x30008000

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

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

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

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

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

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

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

done

Bytes transferred = 2277540 (22c0a4 hex)

[u-boot@MINI2440]# nand erase 0x80000 0x300000

NAND erase: device 0 offset 0x80000, size 0x300000

Erasing at 0x36000001800000 --   0% complete.

OK

[u-boot@MINI2440]#  nand write 30008000 0x80000 300000

NAND write: device 0 offset 0x80000, size 0x300000

Writing at 0x36000000020000 -- 100% is complete. 3145728 bytes written: OK

内核引导:

[u-boot@MINI2440]#  nand read 30008000 0x80000 300000

NAND read: device 0 offset 0x80000, size 0x300000

 3145728 bytes read: OK

[u-boot@MINI2440]# bootm 30008000

## Booting kernel from Legacy Image at 30008000 ...

   Image Name:   tekkaman

   Created:      2010-03-29  12:59:51 UTC

   Image Type:   ARM Linux Kernel Image (uncompressed)

   Data Size:    2277476 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.

Linux version 2.6.33.1 (tekkaman@MAGI-Linux) (gcc version 4.3.2 (crosstool-NG-1.6.1-tekkaman) ) #5 Mon Mar 29 20:58:50 CST 2010

CPU: ARM920T [41129200] revision 0 (ARMv4T), cr=c0007177

CPU: VIVT data cache, VIVT instruction cache

Machine: MINI2440

（略）