Originally based on lpc-toolchain. See its README here.

Pro-tip: People using Debian Buster (and related Linux distributions) can get the required ARM compilers etc. with apt-get install gcc-arm-none-eabi.

UART connectivity

Due to an odd interaction of the Linux kernel with the FTDI UART, as discussed in Marble-Mini Issue #60, establishing communication to the MMC on the prototype (v1.0) Marble-Mini over the UART port involves the following steps:

• Connect USB cable to micro-USB port.
• Open serial port terminal emulator (e.g. gtkterm) on /dev/ttyUSB3 with 115200 baud rate.
• The MMC will most likely be put in reset after the previous step. To restart it:
  • Disable RTS (F8 on gtkterm)
  • Disable DTR (F7 on gtkterm)
• At this point the MMC should restart and print out a menu to the terminal emulator.
• Make selections based on the options provided.

On newer boards, the MMC reset lines are connected to another FTDI channel, so the concerns above can be ignored: just attach to /dev/ttyUSB3 at 115200 baud to get the MMC console. If you actually do want to reset the MMC, start a terminal emulator on /dev/ttyUSB1.

Marble-Mini bringup

• Connect Lab-psu to J17
  • 12 V @ 0.5 A current limit
  • GND pin is the one closer to the barrel connector
• Connect Segger j-link mini or ST-Link v3 to J14
• Download MMC firmware: make marble_download or make marble_mini_download
• Connect to Marble(-Mini) USB port and enter serial terminal: miniterm -e /dev/ttyUSB3 115200 (alternatively) python3 -m serial.tools.miniterm -e /dev/ttyUSB3 115200
• Line-based communication. Hit enter/return to begin message parse/handling
• Type ?<enter> to print help menu
• Push f<enter> for f : XRP7724 flash
• Push g<enter> for g : XRP7724 go
• All power LEDs (close to J12) should be on
• Current consumption should be around 200 mA

Simulated Target

There is a simulated target included in this repo which runs the MMC firmware natively on the host, implementing as much hardware emulation as has been needed for development. This is mostly useful for developers or anyone hoping to get familiar with the interface without access to a Marble board.

Build the simulated target make sim

Run the simulated target make run

There is also a 'wrapped' version of the sim target which redirects input/output to/from a pseudo-terminal (PTY). This is handy for development of scripts designed to talk to the actual hardware over a serial port. make wrap

Nucleo Target

One step closer to the real deal is the Nucleo target which runs on a Nucleo-F207ZG development board (https://www.st.com/en/evaluation-tools/nucleo-f207zg.html). This is handy for tests that use hardware peripherals but either are dangerous or inconvenient to run on a marble. There are a few pin-mapping changes which can be found by looking for #ifdef NUCLEO macro tests throughout the source code (mostly in board_support/marble_v2/marble_board.c).

Build the firmware targeting the nucleo. make nucleo

Download to the nucleo board over its built-in ST-Link v2 SWD programmer/debugger. make nucleo_download

Program FTDI

The FTDI works fine in its default configuration. This step just programs serial number and product name into its USB descriptors.

You need ftdi_eeprom from libfdti:

# building fdti_eeprom 2020-11-12
# from libftdi commit 45ebed37
# cloned from git://developer.intra2net.com/libftdi
# works when running out-of-tree, and different user
# Debian Buster: apt-get install libconfuse2 libconfuse-dev
cd ~/src
mkdir libftdi-git-bin
cd libftdi-git-bin
cmake ~larry/git/libftdi
make ftdi_eeprom
ls -l ftdi_eeprom/ftdi_eeprom

• Enter the unique serial number in ftdi/marble_mini.conf
• Make sure lsusb -d 0403:6011 shows exactly 0 devices, then plug in the Marble-Mini, and see exactly 1 device
• Run ftdi/program_ftdi.sh

Credits

This code base was initially developed as a collaboration between Michal Gaska (WUT) and Larry Doolittle (LBNL), with important contributions from Sergio Paiagua, Vamsi Vytla, Keith Penney, Shreeharshini Murthy, and Michael Betz (LBNL).

Copyright

Marble MMC v1.0 Copyright (c) 2021, The Regents of the University of California, through Lawrence Berkeley National Laboratory (subject to receipt of any required approvals from the U.S. Dept. of Energy) and Creotech Instruments SA. All rights reserved.

If you have questions about your rights to use or distribute this software, please contact Berkeley Lab's Intellectual Property Office at [email protected].

NOTICE. This Software was developed under funding from the U.S. Department of Energy and the U.S. Government consequently retains certain rights. As such, the U.S. Government has been granted for itself and others acting on its behalf a paid-up, nonexclusive, irrevocable, worldwide license in the Software to reproduce, distribute copies to the public, prepare derivative works, and perform publicly and display publicly, and to permit others to do so.