.. SPDX-License-Identifier: GPL-2.0+
.. sectionauthor:: Sumit Garg <sumit.garg@linaro.org>

HMIBSC
======

The HMIBSC is an IIoT Edge Box Core board based on the Qualcomm APQ8016E SoC.
More information can be found on the `SE product page`_.

U-Boot can be used as a replacement for Qualcomm's original Android bootloader
(a fork of Little Kernel/LK). Like LK, it is installed directly into the ``aboot``
partition. Note that the U-Boot port used to be loaded as an Android boot image
through LK. This is no longer the case, now U-Boot can replace LK entirely.

.. _SE product page: https://www.se.com/us/en/product/HMIBSCEA53D1L0T/iiot-edge-box-core-harmony-ipc-emmc-dc-linux-tpm/

Build steps
-----------

First, setup ``CROSS_COMPILE`` for aarch64. Then, build U-Boot for ``hmibsc``::

  $ export CROSS_COMPILE=<aarch64 toolchain prefix>
  $ make hmibsc_defconfig
  $ make

This will build ``u-boot.elf`` in the configured output directory.

Installation
------------

Although the HMIBSC does not have secure boot set up by default, the firmware
still expects firmware ELF images to be "signed". The signature does not provide
any security in this case, but it provides the firmware with some required
metadata.

To "sign" ``u-boot.elf`` you can use e.g. `qtestsign`_::

  $ ./qtestsign.py aboot u-boot.elf

Then install the resulting ``u-boot-test-signed.mbn`` to the ``aboot`` partition
on your device, e.g. with ``fastboot flash aboot u-boot-test-signed.mbn``.

U-Boot should be running after a reboot (``fastboot reboot``).

.. _qtestsign: https://github.com/msm8916-mainline/qtestsign