History

JF 3b835d455f Add explaination about the bootloader.		2020-07-27 21:38:07 +02:00
..
ota-dfu-python	Add python script to DFU from a linux PC to the Pinetime	2020-06-01 15:21:58 +02:00
booloader_app_jlink.ocd	Add example scripts to generate mcuboot image, dfu file and program them with openocd.	2020-05-24 17:47:07 +02:00
boot_graphics.h	Add new target (pinetime-graphics) that flash the bootloader logo into the spi flash memory.	2020-06-06 19:28:01 +02:00
create_dfu.sh	Add example scripts to generate mcuboot image, dfu file and program them with openocd.	2020-05-24 17:47:07 +02:00
create_image.sh	Add example scripts to generate mcuboot image, dfu file and program them with openocd.	2020-05-24 17:47:07 +02:00
flash_bootloader_app.sh	Add example scripts to generate mcuboot image, dfu file and program them with openocd.	2020-05-24 17:47:07 +02:00
mynewt_nosemi_4.1.7.elf	Refactor CMake files to allow building 2 binaries : one standalone and one compatible with mcuboot bootloader (the offset in memory is different).	2020-05-24 16:36:04 +02:00
mynewt_nosemi_4.1.7.elf.bin	Typo in file name.	2020-05-24 17:02:45 +02:00
README.md	Add explaination about the bootloader.	2020-07-27 21:38:07 +02:00

README.md

About this bootloader

This bootloader is mostly developed by Lup Yuen. It is based on MCUBoot and Mynewt.

The goal of this project is to provide a common bootloader for multiple (all?) Pinetime projects. It allows to upgrade the current bootloader and even replace the current application by another one that supports the same bootloader.

As we wanted this bootloader to be as universal as possible, we decided that it should not integrate a BLE stack and provide OTA capabilities.

Integrating a BLE stack for the OTA functionality would have used to much memory space and/or forced all the firmware developers to use the same BLE stack as the bootloader.

When it is run, this bootloader looks in the SPI flash memory if a new firmware is available. It there is one, it swaps the current firmware with the new one (the new one is copied in the main flash memory, and the current one is copied in the SPI flash memory) and run the new one. If the new one fails to run properly, the bootloader is able to revert to the old one and mark the new one as not working.

As this bootloader does not provide any OTA capability, it is not able to actually download a new version of the application. Providing OTA functionality is thus the responsability of the application firmware.

Using the bootlader

Bootloader graphic

The bootloader loads a graphic (Pinetime logo) from the SPI Flash memory. If this graphic is not loaded in the memory, the LCD will display garbage (the content of the SPI flash memory).

The SPI Flash memory is not accessible via the SWD debugger. Use the firmware 'pinetime-graphics' to load the graphic into memory. All you have to do is build it and program it at address 0x00 :

Build:

$ make pinetime-graphics

Program (using OpenOCD for example) :

program pinetime-graphics.bin 0

Let it run for ~10s (it does nothing for 5 seconds, then write the logo into the SPI memory, then (slowly) displays it on the LCD).

Bootloader binary

The binary comes from https://github.com/lupyuen/pinetime-rust-mynewt/releases/tag/v4.1.7

It must be flash at address 0x00 in the internal flash memory.

Using OpenOCD:

program mynewt_nosemi.elf_4.1.7.bin 0

Application firmware image

Build the binary compatible with the booloader:

make pinetime-mcuboot-app

The binary is located in /src/pinetime-mcuboot-app.bin.

It must me converted into a MCUBoot image using imgtool.py from MCUBoot. Simply checkout the project and run the script /scripts/imgtool.py with the following command line:

imgtool.py create --align 4 --version 1.0.0 --header-size 32 --slot-size 475136 --pad-header <build directory>/src/pinetime-mcuboot-app.bin image.bin

The image must be then flashed at address 0x8000 in the internal flash memory.

Using OpenOCD:

program image.bin 0x8000

OTA and DFU

Pack the image into a .zip file for the NRF DFU protocol:

adafruit-nrfutil dfu genpkg --dev-type 0x0052 --application image.bin dfu.zip

Use NRFConnect or dfu.py (in /bootloader/ota-dfu-python) to upload the zip file to the device:

sudo dfu.py -z /home/jf/nrf52/bootloader/dfu.zip -a <pinetime MAC address> --legacy

Note : dfu.py is a slightly modified version of this repo.