Pigweed Experimental

This repository contains a variety experiments to help inform various Pigweed policies, designs, and implementation behaviors.

Code in this repository is not reviewed to the standard of the main Pigweed repository, and generally speaking is untested and maintained on a best-effort basis. This is not a repository of “early access” Pigweed modules, but more so a sandbox for Pigweed contributors to collaborate on investigations. For more information, see the contribution guidelines for the experimental repository and where to land code.

DO NOT DEPEND ON THIS REPOSITORY IN ANY PRODUCTION PROJECT!

Repository setup

Clone this repo with --recursive to get all required submodules.

git clone --recursive https://pigweed.googlesource.com/pigweed/experimental

This will pull the Pigweed source repository into third_party/pigweed. If you already cloned but forgot to --recursive run git submodule update --init to pull all submodules.

pw_graphics

The //pw_graphics folder contains some libraries for drawing to an RGB565 framebuffer and displaying it on various platforms.

The demo applications that make use of these libraries are:

• //applications/terminal_display

Build instructions

First time setup:

git clone --recursive https://pigweed.googlesource.com/pigweed/experimental
cd experimental
. ./bootstrap.sh
pw package install imgui
pw package install glfw
pw package install stm32cube_f4
pw package install pico_sdk

STM32F429-DISC1

Compile:

gn gen out --export-compile-commands --args="
  dir_pw_third_party_stm32cube_f4=\"$PW_PROJECT_ROOT/environment/packages/stm32cube_f4\"
"
ninja -C out

Flash:

openocd -f third_party/pigweed/targets/stm32f429i_disc1/py/stm32f429i_disc1_utils/openocd_stm32f4xx.cfg -c "program out/stm32f429i_disc1_stm32cube_debug/obj/applications/terminal_display/bin/terminal_demo.elf verify reset exit"

STM32F769-DISC0

First time setup:

pw package install stm32cube_f7

Compile:

gn gen out --export-compile-commands --args="
  dir_pw_third_party_stm32cube_f7=\"//environment/packages/stm32cube_f7\"
"
ninja -C out

Flash:

openocd -f targets/stm32f769i_disc0/py/stm32f769i_disc0_utils/openocd_stm32f7xx.cfg \
  -c "program out/stm32f769i_disc0_debug/obj/applications/blinky/bin/blinky.elf verify reset exit"

Linux, Windows or Mac

Compile:

gn gen out --export-compile-commands --args="
  dir_pw_third_party_imgui=\"$PW_PROJECT_ROOT/environment/packages/imgui\"
  dir_pw_third_party_glfw=\"$PW_PROJECT_ROOT/environment/packages/glfw\"
"
ninja -C out

Run:

out/host_debug/obj/applications/terminal_display/bin/terminal_demo

CURRENTLY NOT WORKING (https://pwbug.dev/325649415) - Raspberry Pi Pico Connected to an external SPI display

Working displays:

• ILI9341
• Pico Display Pack 2.0 (ST7789)

First time setup:

pw package install pico_sdk

Compile:

gn gen out --export-compile-commands --args='
  PICO_SRC_DIR="//environment/packages/pico_sdk"
'
ninja -C out

Flash:

• Using a uf2 file:

  1. Reboot pico into BOOTSEL mode by holding the bootsel button on startup.
  2. Copy ./out/rp2040/obj/applications/terminal_display/terminal_demo.uf2 to your Pi Pico.

• Using picotool:

  1. Reboot pico into BOOTSEL mode by holding the bootsel button on startup. Or try forcing a reboot with picotool:

  picotool reboot -f -u
  

  2. Flash the elf or uf2 file and reboot.

  picotool load ./out/rp2040/obj/applications/terminal_display/bin/terminal_demo.elf
  picotool reboot
  

• Using a Pico Probe and openocd:

  This requires installing the Raspberry Pi foundation's OpenOCD fork for the Pico probe. More details including how to connect the two Pico boards is available at Raspberry Pi Pico and RP2040 - C/C++ Part 2: Debugging with VS Code

  Install RaspberryPi's OpenOCD Fork:

  git clone https://github.com/raspberrypi/openocd.git \
    --branch picoprobe \
    --depth=1 \
    --no-single-branch \
    openocd-picoprobe
  
  cd openocd-picoprobe
  
  ./bootstrap
  ./configure --enable-picoprobe --prefix=$HOME/apps/openocd --disable-werror
  make -j2
  make install
  

  Setup udev rules (Linux only):

  cat <<EOF > 49-picoprobe.rules
  SUBSYSTEMS=="usb", ATTRS{idVendor}=="2e8a", ATTRS{idProduct}=="0004", MODE:="0666"
  KERNEL=="ttyACM*", ATTRS{idVendor}=="2e8a", ATTRS{idProduct}=="0004", MODE:="0666"
  EOF
  sudo cp 49-picoprobe.rules /usr/lib/udev/rules.d/49-picoprobe.rules
  sudo udevadm control --reload-rules
  

  Flash the Pico:

  ~/apps/openocd/bin/openocd -f ~/apps/openocd/share/openocd/scripts/interface/picoprobe.cfg -f ~/apps/openocd/share/openocd/scripts/target/rp2040.cfg -c 'program out/rp2040/obj/applications/terminal_display/bin/terminal_demo.elf verify reset exit'
  

  Launching gdb*

  ~/apps/openocd/bin/openocd -f ~/apps/openocd/share/openocd/scripts/interface/picoprobe.cfg -f ~/apps/openocd/share/openocd/scripts/target/rp2040.cfg
  

  gdb-multiarch -ex "target remote :3333" -ex "set print pretty on" out/rp2040/obj/applications/terminal_display/bin/terminal_demo.elf
  

  arm-none-eabi-gdb can be used in place of gdb-multiarch above.

MIMXRT595-EVK Connected to an external MIPI display

Setup NXP SDK:

1. Build a NXP SDK
2. Download SDK
3. Extract SDK's zip file to //environment/SDK_2_12_1_EVK-MIMXRT595

Compile:

gn gen out --export-compile-commands --args="
  pw_MIMXRT595_EVK_SDK=\"//environment/SDK_2_12_1_EVK-MIMXRT595\"
  pw_target_mimxrt595_evk_MANIFEST=\"//environment/SDK_2_12_1_EVK-MIMXRT595/EVK-MIMXRT595_manifest_v3_10.xml\"
  pw_third_party_mcuxpresso_SDK=\"//targets/mimxrt595_evk:mimxrt595_sdk\"
"

ninja -C out

Flash the MIMXRT595-EVK:

Follow the instructions to flash the MIMXRT595-EVK with the SEGGER J-Link firmware and using arm-none-eabi-gdb at https://pigweed.dev/targets/mimxrt595_evk/target_docs.html#running-and-debugging.

Teensy 4.1

https://www.pjrc.com/teensy/loader_cli.html

brew install teensy_loader_cli

OBJCOPY=/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-objcopy
INFILE=out/arduino_debug/obj/applications/terminal_display/bin/terminal_demo.elf
OUTFILE=foo.hex
$OBJCOPY -O ihex -R .eeprom -R .fuse -R .lock -R .signature $INFILE $OUTFILE
teensy_loader_cli --mcu=TEENSY41 -w -v $OUTFILE