Testing BlackMagicProbe with EPM

maksim.drachov · November 1, 2023, 10:04am

Koen has provided Zubax with a patch to the BlackMagicProbe firmware, which adds support for SAMC21, used on EPM/FluxGrip.

Before we can start we need to flash our probe with the latest firmware. We will be using the Dronecode Probe.

To patch the probe:

Clone sources and compile:

git clone https://github.com/blackmagic-debug/blackmagic/
cd blackmagic
make PROBE_HOST=native #compiles into src subfolder

Connect probe and Flash new firmware (see instructions):

lsusb #verify that new usb device detected
sudo dfu-util -d 1d50:6017 -s 0x08002000:leave -R -D src/blackmagic.bin #flashes

Now we should be able to use the probe to flash our EPM board. The pinout of the wires is as follows:

(This is from Pixhawk DS-009 standard)

After connecting this to the corresponding pins on the board, we can do the following:

Make the following change in epm/boards/arm/epm/board.cmake:

Flash the board: west flash --runner blackmagicprobe

The last remaining issue: semihosting.

This is how it is done when using the Atmel debugger:

  $workspace_path/scripts/openocd.cfg &
  # record the PID of the background process
  openocd_pid=$!

  sleep 4s

  # loads the image, runs the tests
  arm-zephyr-eabi-gdb ./build/zephyr/zephyr.elf \
    -batch \
    -silent \
    -ex "tar ext:3333" \
    -ex "load" \
    -ex "monitor arm semihosting enable" \
    -ex "monitor arm semihosting_fileio enable" \
    -ex "run"

  kill $openocd_pid

As far as I understand, the BlackMagicProbe does not require running openocd ourselves, so I’m doing the following steps:

west build -b epm ./verification/on_target/200_command_handler #this builds a test which uses semihosting
arm-zephyr-eabi-gdb-py ./build/zephyr/zephyr.elf #launch GDB
(gdb) target extended-remote /dev/ttyACM0
(gdb) attach 1
(gdb) load
(gdb) monitor arm semihosting enable #these don't seem to work
Target does not support this command.
(gdb) monitor arm semihosting_fileio enable #these don't seem to work
Target does not support this command.
(gdb) set remote system-call-allowed 1 #Pavel suggested this

If I then start running, it seems to “hang”, and if I check test_log.bin (the file where semihosting should be writing its output): it’s empty.

After pressing CTRL+C, I get the following:

maksim.drachov · June 11, 2024, 11:57am

Clone and compile `blackmagic`

git clone git@github.com:blackmagic-debug/blackmagic.git

This issue:

github.com/blackmagic-debug/blackmagic

ST-Link v2 with SWIM as UART configured is too big to fit

opened 12:56AM - 01 Aug 23 UTC

Joebeazelman

I've encountered a series of issues installing BMP. First, I would prefer to dow…nload the latest version of BMP as a binary and flash it to my St-Link v2, but I wasn't sure whether it was configured for SWIM_AS_UART. I presume it must be set at compile time rather than runtime since it's passed as a make argument. There was nothing mentioned about how the firmware was configured. I After cloning the repository, I received the following error: `libopencm3/usb/bos.h: No such file or directory ` I figured the library wasn't installed on my system, so I installed it using brew and the issue persisted. I search online and finally found a BMP issue on GitHub where the user was asked if they had initialized and updated the submodules. Again, nothing mentioned this important step. Ideally, it would be nice if the makefile either checked for the initialization of the submodules and reported an error if they didn't exist or better yet, initialize and update them before starting the build process. I performed the two git submodule operations and was able to build the project up until the link stage where it complained the firmware was too big for the ROM. I search for a solution and there were two other users who are having the same issue, but there was no resolution given. Interestingly, the resulting elf file size they posted is the same as mine. I am also running version 12.2.1 of GCC. ``` ✘ joe@Joes-MacBook-Pro-2  ~/Projects/Repos/blackmagic   main  make PROBE_HOST=stlink ST_BOOTLOADER=1 SWIM_AS_UART=1 BUILD lib/stm32/f1 make[2]: Nothing to be done for `all'. BUILD lib/stm32/f4 make[2]: Nothing to be done for `all'. BUILD lib/lm4f make[2]: Nothing to be done for `all'. Load address 0x08004000 for original ST-LinkV2 Bootloader LD blackmagic.elf /Applications/ArmGNUToolchain/12.2.mpacbti-rel1/arm-none-eabi/bin/../lib/gcc/arm-none-eabi/12.2.1/../../../../arm-none-eabi/bin/ld: address 0x80214e0 of blackmagic.elf section `.text' is not within region `rom' /Applications/ArmGNUToolchain/12.2.mpacbti-rel1/arm-none-eabi/bin/../lib/gcc/arm-none-eabi/12.2.1/../../../../arm-none-eabi/bin/ld: blackmagic.elf section `.ARM.exidx' will not fit in region `rom' /Applications/ArmGNUToolchain/12.2.mpacbti-rel1/arm-none-eabi/bin/../lib/gcc/arm-none-eabi/12.2.1/../../../../arm-none-eabi/bin/ld: address 0x80214e0 of blackmagic.elf section `.text' is not within region `rom' /Applications/ArmGNUToolchain/12.2.mpacbti-rel1/arm-none-eabi/bin/../lib/gcc/arm-none-eabi/12.2.1/../../../../arm-none-eabi/bin/ld: region `rom' overflowed by 5888 bytes Memory region Used Size Region Size %age Used rom: 136960 B 128 KB 104.49% ram: 3876 B 20 KB 18.93% collect2: error: ld returned 1 exit status make[1]: *** [blackmagic.elf] Error 1 make: *** [all] Error 2 ``` The firmware doesn't fit but so you must acquit.

We need to remove stm32 support so the compilation won’t fail:

make PROBE_HOST=native

pavel-kirienko · June 11, 2024, 12:03pm

Yeah, we really need to make a new version of DroneCode Probe with a larger MCU. The Black Magic Probe project has several larger MCU options supported out of the box. This could be one of the possible tasks for the intern to work on initially: it is simple and well-contained.

maksim.drachov · June 11, 2024, 12:10pm

Let’s start using consistent naming in posts and documentation, otherwise it’s gonna be harder to find.

maksim.drachov · June 12, 2024, 3:41pm

It works using BugFace:

I’ve had to make the following change:

maksim.drachov · June 12, 2024, 5:01pm

Now it’s failing again, even when using BugFace.

maksim.drachov · June 13, 2024, 11:36am

Flashing FluxGrip with BugFace2

You will need:

FluxGrip
CanFace 2

BugFace2

Before flashing, we should update the firmware on the BlackMagicProbe module present on the board.

We’re using commit f1cd9f2b which introduced SAMC21 support.

We make the following change due to flash memory constraints in our MCU:

diff --git a/src/Makefile b/src/Makefile
index 0e096d18..ae8fac3f 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -73,13 +73,6 @@ SRC =              \
        spi.c          \
        stm32f1.c      \
        ch32f1.c       \
-       stm32f4.c      \
-       stm32h5.c      \
-       stm32h7.c      \
-       stm32mp15.c    \
-       stm32l0.c      \
-       stm32l4.c      \
-       stm32g0.c      \
        renesas.c      \
        target.c       \
        target_flash.c \
(END)

Compile the firmware:

make clean
make PROBE_HOST=native

To update CF2, do the following:

Disconnect from power/usb
Put CF2 into bootloader mode by pushing the switch towards the ON state:

Connect back to USB
Now using lsusb, you should be able to see that the BlackMagicProbe is connected in DFU mode:

Update/flash the firmware:

sudo dfu-util -d 1d50:6017 -s 0x08002000:leave -R -D src/blackmagic.bin

Disconnect the USB
Put the BlackMagicProbe back into application mode (toggle the switch from before).
Re-connect the USB:

Linux

Now we need to do some Linux setup:

Copy/download some udev rules for automatically detecting BlackMagicProbe:

sudo wget -O /etc/udev/rules.d/99-blackmagic.rules https://gist.github.com/maksimdrachov/15f8f4297eb02fea2aff7cd5e5a1b294/raw/2d8a93484712bcfb8ff126fc5d69de902c640b2f/99-blackmagic.rules

Reload udev rules and trigger them:

sudo udevadm control --reload-rules
sudo udevadm trigger

Now we should see the following 2 entries under /dev/:

Flash

Make the following change in fluxgrip_software:

diff --git a/epm/boards/arm/epm/board.cmake b/epm/boards/arm/epm/board.cmake
index e181152..a493645 100644
--- a/epm/boards/arm/epm/board.cmake
+++ b/epm/boards/arm/epm/board.cmake
@@ -1,4 +1,4 @@
 # Copyright (c) 2022 Kamil Serwus
 # SPDX-License-Identifier: Apache-2.0

-include(${ZEPHYR_BASE}/boards/common/openocd.board.cmake)
+include(${ZEPHYR_BASE}/boards/common/blackmagicprobe.board.cmake)

west flash

maksim.drachov · June 13, 2024, 12:04pm

To upload the bootloader:

(This should be done once for each board. After that, as long as you’re using west flash with the memory set correctly, the bootloader will remain in place.)

arm-zephyr-eabi-gdb -q
(gdb) set confirm off
(gdb) target extended-remote /dev/ttyBmpGdb
(gdb) monitor swdp_scan
(gdb) attach 1
(gdb) load /home/kanye/fluxgrip_bootloader/bootloader.elf
(gdb) kill
(gdb) quit

pavel-kirienko · June 13, 2024, 12:08pm

To upload the bootloader:

You can also go like: ./commission.py

No arguments needed

pavel-kirienko · October 21, 2024, 6:29am

Here’s the built binary:

blackmagic.bin (103.6 KB)

It should not be released because it omits support for popular STM32 MCUs. We should prepare another build that removes something else instead, not STM32.

maksim.drachov · October 28, 2024, 4:54pm

With this binary semihosting works:

backup.bin (120 KB)

(I don’t know what’s different about it, downloaded it from my previous CanFace)