75xx spiflash restore
From embeddedTS Manuals
This needs to be done directly on the SBC. You can find the latest SPI image here. Once downloaded you can decompress the image using bzip2:
bzip2 -d 4mb-spiflash-latest.dd.bz2
Some of this series contains a 4MB SPIflash embedded on the board that can be written to by specifying lun 0, or "-l 0" which will use that chip select. The offboard flash found on various baseboards, or console boards like the TS-9448 or TS-9449 can be written to using lun 1, or "-l 1".
Backup
Backup the entire SPI flash containing the MBR, Kernel, and initrd
spiflashctl -l 1 -R 64 -z 65536 > spiflash.dd
Backup only the Kernel
spiflashctl -l 1 -R 4095 -z 512 -k part1 > /temp/zImage
Backup only the Initrd
spiflashctl -l 1 -R 32 -z 65536 -k part2 > /temp/initrd
Restore
Write the entire SPI flash containing the MBR, Kernel, and initrd
spiflashctl -l 1 -W 64 -z 65536 -i /path/to/4mb-spiflash-latest.dd
Write a new Kernel
spiflashctl -l 1 -W 4095 -z 512 -k part1 -i /temp/zImage
Write a new Initrd
spiflashctl -l 1 -W 32 -z 65536 -k part2 -i /temp/initrd