[U-Boot] i.mx6 board booting

[JYOTI DUBEY]

I followed the following commands to achieve a successful booting of i.mx6
board using SD card
dd if=u-boot.imx of=/dev/sdb bs=1k seek=1
The above command burnt the u-boot.imx image on the SD card though nothing
was seen on SD card.
Next the gtkterm configurations were set and after the board was started
serial console output was interrupted(by pressing a key).
U-Boot>> sf probe (to probe the flash memory)
U-Boot>> sf erase 0 0x80000 (to erase the flash)
U-Boot>>fatload mmc 1 12000000 u-boot.imx
The above command throws an error -"Unable to read file u-boot.imx"

SO what can be the problem behind it and how can we overcome it?