由于实验室只有要用到多块 TX1 开发板, 然而一个个都用 JetPack 刷机, 再用自动化脚本装软件和依赖实在是太麻烦了, 因此我和梅老板就开始研究怎么直接备份 TX1 上的 Ubuntu 系统.

Failed attempts

最开始想的是直接用dd来备份整块 eMMC到外置的存储上, 于是尝试了

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$ sudo dd if=/dev/mmcblk0p1 of=/media/ubuntu/backup/backup.img

后来还发现可以用ssh来远程dd

  • run from remote computer:
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$ dd if=/dev/mmcblk0p1 | gzip -1 - | ssh yuthon@mac dd of=image.gz
  • run from local computer:
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$ ssh ubuntu@tx1 "dd if=/dev/mmcblk0p1 | gzip -1 -" | dd of=image.gz

之后, 我们发现64_TX1/Linux_for_Tegra_64_tx1/rootfs目录中应该就是之后需要拷到 TX1 的/目录下的内容. 因此我们直接将之前备份好的bakcup.img解压到了此目录下, 并使用 JetPack 重新 Flash OS.

最后的结果是 TX1 在重启后卡在了登录界面, 经典的 login-loop.

此方案, 扑街.

Using tegraflash.py

Then we found a post on NVIDIA Developer Forums, and method in this post works for us.

Assumed we’re in 64_TX1/Linux_for_Tegra_64_tx1/bootloader directory.

Backup an image

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$ sudo ./tegraflash.py --bl cboot.bin --applet nvtboot_recovery.bin --chip 0x21 --cmd "read APP my_backup_image_APP.img"

Restore an image

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$ sudo ./tegraflash.py --bl cboot.bin --applet nvtboot_recovery.bin --chip 0x21 --cmd "write APP my_backup_image_APP.img"

One more thing

It’s recommended in the post to use flash.py front-end instead of tegraflash.py to make sure you use the same L4T release version.

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# Backup
$ sudo flash.sh -S 14580MiB jetson-tx1 mmcblk0p1
# Restore
$ sudo flash.sh -r -S 14580MiB jetson-tx1 mmcblk0p1

Note that the -r param re-uses system.img in bootloader directory, and if a clone file is there in place, that installs the clone. I haven’t tried this method, maybe you could have a try and report.