This document describes how to develop for Passport.
While Passport may compile on other Linux distributions, the instructions below are based on Ubuntu 18.04, which is also what is used for official Passport builds.
The instructions below assume you are installing into your home folder at ~/passport-firmware. You can choose
to install to a different folder, and just update command paths appropriately.
cd ~/
git clone [email protected]:Foundation-Devices/passport-firmware.git
Several tools are required for building and debugging Passport.
sudo apt install gcc-arm-none-eabi
cd ~/passport-firmware
make -C mpy-cross
sudo apt install autotools-dev
sudo apt install automake
sudo apt install libusb-1.0-0-dev
sudo apt install libtool
cd ~/
git clone https://github.com/ntfreak/openocd.git
cd ~/openocd/
./bootstrap
./configure --enable-stlink
make
sudo make install
cd ~/
git clone https://github.com/dhylands/rshell
sudo apt install python3-pip
sudo pip3 install rshell # (this should install rshell in /usr/local/)
To use Just for running commands, first follow the instructions here: https://github.com/casey/just#installation to install Just. Note that Pillow must be updated to 8.3.1 for all commands to work properly.
Once Just has been installed, the developer can use just commands to perform actions such as building, flashing, resetting and even taking screenshots of the displays screen.
Note that all just commands must be run from ports/stm32/ directory.
Here are some of the most common just commands and their usages:
just flash {version} - Builds if necessary, signs with a user key and then flashes the device with the firmware binary created under `build-Passport/`
just reset - Resets the device
just screenshot {filename} - Screenshots the device and saves to the desired filename
See the Justfile included in our source for the full list of just commands.
You will need several shell windows or tabs open to interact with the various tools.
In one shell, make sure that you cd to the root stm32 source folder, e.g., cd ~/passport-firmware/ports/stm32:
make BOARD=Passport
To include debug symbols for use in ddd, run the following:
make BOARD=Passport DEBUG=1
You should see it building various .c files and freezing .py files. Once complete, the final output should look similar to the following:
LINK build-Passport/firmware.elf
text data bss dec hex filename
475304 792 57600 533696 824c0 build-Passport/firmware.elf
GEN build-Passport/firmware.dfu
GEN build-Passport/firmware.hex
If you are using just commands, then building the firmware can be done by running the following command:
just build
In order to load the files onto the device, they need to first be signed by two separate keys.
The cosign program performs this task, and it needs to be called twice with two separate
private keys.
First, you need to build the cosign tool and copy it somewhere in your PATH:
sudo apt-get install libssl-dev
cd ports/stm32/boards/Passport/tools/cosign
make
cp x86/release/cosign ~/.local/bin # You can run `echo $PATH` to see the list of possible places you can put this file
Next you need to sign the firmware twice. The cosign tool appends -signed to the end of the main filename each time it signs.
Assuming you are still in the ports/stm32 folder run the following:
# TODO: Update command arguments once final signing flow is in place
cosign -f build-Passport/firmware.bin -k 1 -v 0.9
cosign -f build-Passport/firmware-signed.bin -k 2
You can also dump the contents of the firmware header with the following command:
cosign -f build-Passport/firmware-signed-signed.bin -x
If you are using just commands, then signing the firmware can be done by running the following command with the desired version:
just sign 1.0.7
It will build the firmware first if necessary.
To build the bootloader do the following:
cd ports/stm32/boards/Passport/bootloader folder
make
OpenOCD server provides a socket on localhost:4444 that you can connect to and issue commands. This server acts as an intermediary between that socket and the board connected over JTAG.
Once the OpenOCD server is running, you can pretty much ignore this window. You will interact with the OpenOCD client window (see below). Open a second shell and run the following:
/usr/local/bin/openocd -f stlink.cfg -c "adapter speed 1000; transport select hla_swd" -f stm32h7x.cfg
You should see output similar to the following:
Open On-Chip Debugger 0.10.0+dev-01383-gd46f28c2e-dirty (2020-08-24-08:31)
Licensed under GNU GPL v2
For bug reports, read
http://openocd.org/doc/doxygen/bugs.html
hla_swd
Info : The selected transport took over low-level target control. The results might differ compared to plain JTAG/SWD
Info : Listening on port 6666 for tcl connections
Info : Listening on port 4444 for telnet connections
Info : clock speed 1800 kHz
Info : STLINK V2J29S7 (API v2) VID:PID 0483:3748
Info : Target voltage: 2.975559
Info : stm32h7x.cpu0: hardware has 8 breakpoints, 4 watchpoints
Info : starting gdb server for stm32h7x.cpu0 on 3333
Info : Listening on port 3333 for gdb connections
We use telnet to connect to the OpenOCD Server. Open a third shell and run the following:
telnet localhost 4444
From here can connect over JTAG and run a range of commands (see the help for OpenOCD for details):
Whenever you change any code in the bootloader folder or in the common folder, you will need to rebuild the bootloader (see above), and then flash it to the device with the following sequence in OpenOCD:
reset halt
flash write_image erase boards/Passport/bootloader/arm/release/bootloader.bin 0x8000000
reset
The following command sequence is one you will run repeatedly (i.e., after each build):
reset halt
flash write_image erase build-Passport/firmware-signed-signed.bin 0x8020000
reset
These commands do the following:
- Stop execution of code on the MCU
- Write the firmware to flash at address 0x8000000
- Reset the MCU and start executing code at address 0x8000000
If you are using just commands, ocd and telnet steps are not required and instead, flashing the firmware can be done using the following command with the desired version number:
just flash 1.0.7
It will build and sign the firmware first if necessary.
We use rshell to connect to the MicroPython device over USB serial. Open another shell and run:
sudo rshell -p /dev/ttyUSB0
This gives us an interactive shell where we can do things like inspect the flash file system, or run a REPL:
ls -la /flash- Get a listing of the files in/flashon the devicecp local_folder/my_math.py /flash- Copy a local file into/flashrepl- Open a MicroPython REPL. If there are any files in/flash, you can import them. For example:
import my_math
my_math.add(1, 2)
To debug the firmware, open a new shell window or tab and run the following command from the passport/ports/stm32 folder:
ddd --debugger gdb-multiarch build-Passport/firmware.elf &
To debug the bootloader, open a new shell window or tab and run the following command from the passport/ports/stm32/boards/Passport/bootloader folder:
ddd --debugger gdb-multiarch bootloader.elf &
Go to the telnet session with OpenOCD and run the following to prepare to connect DDD:
reset halt
Next, connect DDD to the OpenOCD GDB server with:
target remote localhost:3333
From here you can run normal GDB commands like:
b stm32_main # Stop at stm32_main, which is MicroPython's entry point
list main.c # Show the main.c file at line 1
c # continue
n # step over
s # step into