The following instructions will help you to flash partition table and
prebuilt bootloader onto Poplar board.

* Find a USB disk formated with FAT file system, copy fastboot.bin and
  recovery_files/ folder onto the disk.

* Attach the USB disk to USB port J2 (next to IR receiver), and power on
  Poplar board with button S3 (USB_BOOT) pressed until following
  messages are seen on serial output.

    Entry usb bootstrap

    Usb disk(1):
    Decrypt auxiliary code ...OK

* Hit any key to stop U-Boot autoboot and get into the prompt.

* Run U-Boot commands below to install partition table and bootloader.

    poplar# usb reset
    poplar# fatload usb 0:1 ${scriptaddr} recovery_files/install.scr
    poplar# source ${scriptaddr}

These instructions are only necessary for initial bootloader
installation or board unbricking.  Once the initial installation is
completed, you can update bootloader with fastboot support as below.

* Connect Poplar (USB port J2) to PC with a Male-to-Male USB cable.

* Power on Poplar, get into U-Boot prompt and run command below.

    poplar# fastboot 0

* On PC side, run command below to update the bootloader.

    $ fastboot flash mmcsda1 loader.bin

To install the AOSP images, use fastboot commands as below.

    $ fastboot flash mmcsda2 boot.img
    $ fastboot flash mmcsda3 system.img
    $ fastboot flash mmcsda5 vendor.img
    $ fastboot flash mmcsda6 cache.img
    $ fastboot flash mmcsda7 userdata.img