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如何备份 Linux 内核映像

tag-icon • tag-icon linux arch-linux embedded flash-memory
如何备份 Linux 内核映像

主板采用 ARM926EJ CPU，运行嵌入式 Linux v2.6.26.5，在 NAND 闪存设备上，NAND 32MiB。 Linux 位于 NAND 设备上的 MTD 分区上。

如何从串行接口备份 Linux 内核映像 (SP2Xcybertan_rom_bin)？由于没有 TFTP 选项可以通过 tftp 将文件从板传输到主机 PC。我可以将 nand 读取到某个内存地址，将输出转储到终端并保存，然后将十六进制转换为二进制：

nand read 0x20000000  0x80000  0x0017FF80
md.b 0x20000000 0x0017FF80

从启动过程日志：

U-Boot 2009.03 (Oct 06 2011 - 20:04:03)

Stack:->21F1EC74 U-Boot code: 21FC4D00->21FF9454  BSS:->21FFFF3B
CPU: PNX8181-2B OM6xxx-ARM926EJ-S(ARMv5TEJ) @ 221MHz(armclk), 110MHz(hclk)
Board: Vega_PNX8181_BaseStation Platform IV (LC)
I2C:   ready
RAM Configuration:
Bank #0: 20000000 32 MB
NAND:  32 MiB
In:    serial
Out:   serial
Err:   serial
Use Full Image's Kernel
Net:   VLAN Mode
L2 switch present
ETN1
Hit any key to stop autoboot:  0 

Loading from NAND 32MiB 3,3V 8-bit, offset 0x80000
   Image Name:   SP2Xcybertan_rom_bin
   Created:      1970-01-01   0:00:-1 UTC
   Image Type:   ARM Linux Kernel Image (uncompressed)
   Data Size:    1572736 Bytes =  1.5 MB
   Load Address: 20008000
   Entry Point:  20008000
## Booting kernel from Legacy Image at 20200000 ...
   Image Name:   SP2Xcybertan_rom_bin
   Created:      1970-01-01   0:00:-1 UTC
   Image Type:   ARM Linux Kernel Image (uncompressed)
   Data Size:    1572736 Bytes =  1.5 MB
   Load Address: 20008000
   Entry Point:  20008000
   Verifying Checksum ... OK
   Loading Kernel Image ... OK
OK

Starting kernel ...
Uncompressing Linux.........

环境变量

firetux # printenv
baudrate=115200
ethaddr=FF:FF:FF:FF:FF:FF
netmask=255.255.255.0
ipaddr=192.168.1.1
serverip=192.168.1.100
bootfile=firetux.kernel
bootcmd1=setenv bootargs ${bootargs} && nboot 0x20200000 0 ${image_addr} && bootm 0x20200000
bootcmd2=setenv bootargs ${bootargs} && tftpboot 20200000 firetux.kernel && bootm 20200000
phymode=auto
mtdids=nand0=gen_nand
unlock=yes
verify=y
update.uboot=echo Update u-boot && tftpboot 0x20000000 nandboot.flash && nand erase 0x0 0x03ffff && nand write.jffs2 0x20000000 0x0 ${filesize}
update.kernel=echo Update kernel && tftpboot 0x20000000 uImage && nand erase 0x80000 0x180000 && nand write.jffs2 20000000 0x80000 0x180000
update.romimg=echo Update RomImage && tftpboot 0x20000000 romimage.img && nand erase 0x80000 0x13e0000&& nand write.jffs2 20000000 0x80000 ${filesize}
update.halfimg=echo Update HalfImage && tftpboot 0x20000000 recovery.img && nand erase 0x1460000 0x700000&& nand write.jffs2 20000000 0x1460000 ${filesize}
eraseenv=echo Erase Environment && nand erase 0x60000 0x20000
HwModel=Hw_Model=SPA122
bootcmd=run bootcmd1
halfImage=half_image=0
cy_boot_code_ver=1.0.1 (Oct  6 2011 - 20:04:00)
RouterMode=Router_Mode=0
stdin=serial
stdout=serial
stderr=serial
bootcmd=run bootcmd1
image_addr=0x80000
bootargs=console=ttyS1,115200n8 rootfstype=squashfs noalign half_image=0 verify=y Hw_Model=SPA122 Router_Mode=0
ethact=ETN1
bootdelay=3

kernel(uImage) 和 romimage (romimg.img) 在启动过程方面有什么区别？

答案1

执行此操作的步骤如下：

首先假设更新uImage是正确的

update.kernel=echo Update kernel && tftpboot 0x20000000 uImage && nand erase 0x80000 0x180000 && nand write.jffs2 20000000 0x80000 0x180000

然后：

nand read <memory offset> <nand start offset> <size>
md <memory offset> <size>

所以：

nand read 0x20000000 0x80000 0x180000
md 0x20000000 0x180000

然后，您需要找到一种方法来记录序列号上的输入，并使用脚本对其进行解析，以获取十六进制字节并将它们以二进制形式输出到文件中。

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