Unable to boot Fu540-hifive unleashed board from spi-nor

hello all,

As i am try to boot from spi-nor flash memory, with the yocto image, i am customized image with in 32MB but if i am placed it in the flash memory the board is not booting up, placed fsbl also, but if i copied with the hifive_unleashed.gpt image which is available in the sifive website its booting up.
i followed these steps to create a single image which is to be loaded in to the spi-nor.

*Steps

  1. dd if=/dev/zero of=./diskimage
  2. losetup /dev/loop20 diskimage
    3)using zcat for yocto image copying all three partitions to /dev/loop20 which has diskimage.gpt file
    4)using scp copy the disk image the board.
    5)in the board, flashcp -v diskimage.gpt /dev/mtd0

Note- craeted the 4 partions with the same UUID as the zsbl can decode, but still its not booting