UNISOC Zephyr SDK
=================
The UNISOC Zephyr SDK is provided for convenience and ease of use.
It provides everything you need for development of UNISOC hardware
platform except the cross-compilation toolchain, including
bootloader and Zephyr portings, top level customized applications
and programming tools.

In addition to cross-compilers, please refer to 'Getting Started Guide'.
https://docs.zephyrproject.org/latest/getting_started/getting_started.html#getting-started-guide


Building
========
The UNISOC Zephyr SDK supports building multiple profiles.
All supported profiles are stored in the directory 'apps',
and can be listed by the following command:

  find apps/ -mindepth 1 -maxdepth 1 -type d ! -name ".*" -exec basename {} \;

To build a specific profile, use the following the command:

  PROFILE=repeater make

Note that the default profile is repeater.

After the compilation, the images can be found in the directory 'output/repeater/images/'.
fdl*.bin - Flash downloader
mcuboot-pubkey*.bin - Bootloader
zephyr-signed-ota*.bin - Kernel
wcn-modem* - WCN Modem


Updating Firmware
=================
To update firmware, please follow the procedure below:

0. Install the flash programming tool before updating.
Download the .deb package and install it.
https://github.com/unisoc/dloader/releases/download/unisoc-v0.3.1/dloader_0.3.1-1_amd64.deb

  sudo dpkg -i dloader_0.1-1_amd64.deb

In addition, you can build the flash programming tool.

  make dloader

1. Switch bootstrap pin to ROM Code mode.
  ┌──────────────┐
  │ ┌─┐   ┌─┐┌─┐ │
  │ │O│ O │O││O│ │
  │ ├─┤┌─┐├─┤├─┤ │
  │ │O││O││O││O│ │
  │ └─┘├─┤└─┘└─┘ │
  │  O │O│ O  O  │
  │    └─┘       │
  └──────────────┘

2. Power on the board, and execute the following sequence of commands:

  cd output/repeater/images
  ./update_fw.sh

3. Switch bootstrap pin to NOR Flash mode again and push the reset button.
  ┌──────────────┐
  │    ┌─┐┌─┐┌─┐ │
  │  O │O││O││O│ │
  │ ┌─┐├─┤├─┤├─┤ │
  │ │O││O││O││O│ │
  │ ├─┤└─┘└─┘└─┘ │
  │ │O│ O  O  O  │
  │ └─┘          │
  └──────────────┘

To update one image or several images, please refer to help of update_fw.sh.

  ./update_fw.sh -h

Debugging
=========
At present, debugging with the J-Link and GDB is the only choice.
To set the debugging environment, please follow the procedure below:

1. Download J-Link Software Pack through and install it.
https://www.segger.com/downloads/jlink/JLink_Linux_V630b_x86_64.deb
  sudo dpkg -i Downloads/JLink_Linux_V630b_x86_64.deb

2. Put Unisoc_UWP566X.JLinkScript to /opt/SEGGER/JLink/Samples/JLink/Scripts.
  cp Unisoc_UWP566X.JLinkScript /opt/SEGGER/JLink/Samples/JLink/Scripts

3. Start the J-Link GDB server
  JLinkGDBServer -device Cortex-M4 -endian little -if SWD -speed 8000 -jlinkscriptfile /opt/SEGGER/JLink/Samples/JLink/Scripts/Unisoc_UWP566X.JLinkScript

4. Start the debug session using GDB client