75XX MicroSD Recovery: Difference between revisions
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If backing up on a separate workstation, keep in mind windows does not have direct block device support needed to write these images. You will also need to determine the SD card device. You can usually find this in the output of 'dmesg' after inserting the SD card and you will typically see something like '/dev/sdb' as the block device and '/dev/sdb1' for the first partition. On some newer kernels you will see '/dev/mmcblk0' as the block device and '/dev/ | If backing up on a separate workstation, keep in mind windows does not have direct block device support needed to write these images. You will also need to determine the SD card device. You can usually find this in the output of 'dmesg' after inserting the SD card and you will typically see something like '/dev/sdb' as the block device and '/dev/sdb1' for the first partition. On some newer kernels you will see '/dev/mmcblk0' as the block device and '/dev/mmcblk0p1' for the first partition. For these examples I will use the '/dev/mmcblk0' format. | ||
If you are backing up directly on the board you will likely need to use some kind of offboard storage like a thumbdrive or external hard drive. Make sure you have any nbd devices unmounted before trying to restore new ones. | If you are backing up directly on the board you will likely need to use some kind of offboard storage like a thumbdrive or external hard drive. Make sure you have any nbd devices unmounted before trying to restore new ones. |
Revision as of 17:29, 31 July 2012
If backing up on a separate workstation, keep in mind windows does not have direct block device support needed to write these images. You will also need to determine the SD card device. You can usually find this in the output of 'dmesg' after inserting the SD card and you will typically see something like '/dev/sdb' as the block device and '/dev/sdb1' for the first partition. On some newer kernels you will see '/dev/mmcblk0' as the block device and '/dev/mmcblk0p1' for the first partition. For these examples I will use the '/dev/mmcblk0' format.
If you are backing up directly on the board you will likely need to use some kind of offboard storage like a thumbdrive or external hard drive. Make sure you have any nbd devices unmounted before trying to restore new ones.
You can find the latest SD card image here. Make sure you decompress the image first before writing.
From Workstation
Backup
Entire SD card
dd if=/dev/mmcblk0 of=/path/to/backup.dd bs=32k && sync && sync
Kernel
dd if=/dev/mmcblk0p2 of=/path/to/zImage bs=32k && sync && sync
Initrd
dd if=/dev/mmcblk0p3 of=/path/to/initrd bs=32k && sync && sync
Restore
Entire SD card
dd if=/path/to/backup.dd of=/dev/mmcblk0 bs=32k && sync
Kernel
dd if=/path/to/zImage bs=32k of=/dev/mmcblk0p2 && sync
Initrd
dd if=/initrd bs=32k of=/dev/mmcblk0p3 && sync
From SBC
Backup
Entire card
# Determine the block size
eval $(sdctl)
dd if=/dev/nbd5 of=/path/to/backup.dd bs=512 count=$cardsize_sectors conv=sync && sync
Kernel
sdctl -R 4096 -z 512 --seek part1 > kernel
Initrd
sdctl -R 4096 -z 512 --seek part2 > initrd
Restore
The entire card from SBC
dd if=/path/to/2gbsd-noeclipse-latest.dd bs=512 conv=sync of=/dev/nbd5 && sync
Kernel
dd if=/mnt/root/zImage bs=512 conv=sync of=/dev/nbd7 && sync
Initrd
dd if=/mnt/root/initrd bs=512 conv=sync of=/dev/nbd8 && sync