Update uboot and kernel

Update uboot and kernel

From the above ETH burning principle analysis, update uboot and kernel only need to perform the following three steps in uboot
Take updating uboot as an example:

• Ubuntu looks at the contents of uboot.es

  # cat images/scripts/\[\[uboot.es

  

• In turn uboot.es Command in
  Remind:The command is executed in uboot mode
  Enter uboot mode: Press and hold the Enter key to supply power, or enter reboot and press and hold the Enter key

  tftp 0x21000000 uboot_s.bin
  nand erase.part UBOOT0
  nand write.e 0x21000000 UBOOT0 ${filesize}
  nand erase.part UBOOT1
  nand write.e 0x21000000 UBOOT1 ${filesize}

• Power on again
  or reset