The RCE bootloader (U-Boot) can read and write DOS formatted FAT partitions located on the SD card.
This feature can be used in an emergency to restore a file.
The RCE serial console must be used for this operation.
The bootloader countdown must be enabled in order to enter the bootloader shell.
Reboot the RCE and press any key to enter to enter the bootloader shell.
To list the contents of a partition:
zynq-uboot> fatls mmc 0:1
13706024 boot.bin
13321506 fpga.bit
131072 uboot.env
3 file(s), 0 dir(s)
zynq-uboot> fatls mmc 0:7
9984 devicetree.dtb
9988 devicetree_ramdisk.dtb
3678504 uimage
5289509 uramdisk.image.gz
4 file(s), 0 dir(s)
To restore a file, first load it into memory at 0x700000
zynq-uboot> fatload mmc 0:7 0x700000 uimage
reading uimage
3678504 bytes read in 629 ms (5.6 MiB/s)
Convert the bytes read count to a hexadecimal value, then write the file to the SD
zynq-uboot> fatwrite mmc 0:7 0x700000 uimage.backup 0x382128
writing uimage.backup
3678504 bytes written in 770 ms (4.6 MiB/s)
zynq-uboot>