Interrupting soft reset (Ctrl-D) with Ctrl-C erases filesystem on Raspberry Pi Pico
Sending a Ctrl-D to the MicroPython REPL to initiate a soft reset and then immediately issuing a Ctrl-C causes the entire filesystem to be erased on the Raspberry Pi Pico board. This issue was observed on 2 separate Pico boards across the following nightly builds (the 4 latest as of 01 March 2023):
However, the bug was not observed in the latest stable version 1.19.1.
Steps to reproduce
These steps were tested on a Linux host (Ubuntu 22.04).
First, load one of the above nightly versions of MicroPython onto a Raspberry Pi Pico board.
Next, using mpremote, install a library on the Pico’s filesystem, for example hashlib:
mpremote mip install hashlib
Then check that the library exists on the Pico’s filesystem:
mpremote fs ls /lib
This should show the hashlib folder:
ls :/lib
0 hashlib/
Then, to send the required keystrokes (Ctrl-D followed by Ctrl-C), execute the following lines of Python on the Linux host machine to which the Pico is connected, replacing /dev/ttyACM0 with the serial port of the MicroPython REPL. This script requires pyserial.
import serial
s = serial.Serial('/dev/ttyACM0')
s.write(b'\x04') # Ctrl-D
s.write(b'\x03') # Ctrl-C
s.close()
Less precisely, the issue can also be reproduced by entering a REPL with mpremote and pressing Ctrl-D and Ctrl-C in rapid succession.
Then check the Pico’s filesystem once again:
mpremote fs ls
This should show that the lib folder and all files it contains have been removed:
ls :
This issue became evident because the visual studio code extension Pico-W-Go exhibits this behaviour when running a MicroPython file, issuing a Ctrl-D and Ctrl-C in rapid succession before running the given code. This issue has been reported on that project’s GitHub page here, suggesting it affects other nightly versions older than the 4 listed above.
mpremote with mount fails on ESP32
Re-installed mpremote today - tail end of pip3:
Successfully installed mpremote-0.0.5
ESP32 works OK, with ctrl-d resetting the ESP uneventfully if there is no mount.
With a mount, ctrl-d kills mpremote. In the following, when the REPL appeared I pressed ctrl-d:
>>> [adminpete@capybara]: ~/temp
$ mpremote mount .
Local directory . is mounted at /remote
Connected to MicroPython at /dev/ttyUSB0
Use Ctrl-] to exit this shell
>
MicroPython v1.16 on 2021-06-28; ESP32 module with ESP32
Type "help()" for more information.
>>>
MPY: soft reboot
Traceback (most recent call last):
File "/home/adminpete/.local/lib/python3.8/site-packages/mpremote/main.py", line 452, in main
do_repl(pyb, args)
File "/home/adminpete/.local/lib/python3.8/site-packages/mpremote/main.py", line 332, in do_repl
do_repl_main_loop(
File "/home/adminpete/.local/lib/python3.8/site-packages/mpremote/main.py", line 259, in do_repl_main_loop
pyb.soft_reset_with_mount(console_out_write)
File "/home/adminpete/.local/lib/python3.8/site-packages/mpremote/pyboardextended.py", line 612, in soft_reset_with_mount
self.exec_(fs_hook_code)
File "/home/adminpete/.local/lib/python3.8/site-packages/mpremote/pyboard.py", line 465, in exec_
ret, ret_err = self.exec_raw(command, data_consumer=data_consumer)
File "/home/adminpete/.local/lib/python3.8/site-packages/mpremote/pyboard.py", line 456, in exec_raw
self.exec_raw_no_follow(command)
File "/home/adminpete/.local/lib/python3.8/site-packages/mpremote/pyboard.py", line 453, in exec_raw_no_follow
raise PyboardError("could not exec command (response: %r)" % data)
mpremote.pyboard.PyboardError: could not exec command (response: b'R\x01')
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/home/adminpete/.local/bin/mpremote", line 8, in <module>
sys.exit(main())
File "/home/adminpete/.local/lib/python3.8/site-packages/mpremote/main.py", line 455, in main
do_disconnect(pyb)
File "/home/adminpete/.local/lib/python3.8/site-packages/mpremote/main.py", line 208, in do_disconnect
pyb.umount_local()
File "/home/adminpete/.local/lib/python3.8/site-packages/mpremote/pyboardextended.py", line 620, in umount_local
self.exec_('uos.umount("/remote")')
File "/home/adminpete/.local/lib/python3.8/site-packages/mpremote/pyboard.py", line 467, in exec_
raise PyboardError("exception", ret, ret_err)
mpremote.pyboard.PyboardError: ('exception', b'', b'Traceback (most recent call last):\r\n File "<stdin>", line 1, in <module>\r\nOSError: [Errno 22] EINVAL\r\n')