LittleFS FSUpload example - I'm not quite sure this is really working.

[fapplin]

So, I tried to run the LittleFS/FSUpload example.

It would give me an output, like:

I have been run 12 times
---------------

but, I never got anything else. So, I hunted for the file "counts.txt" and it wasn't anywhere on my system. I found the "file1.txt" in my

/home/frank/.arduino15/packages/rp2040/hardware/rp2040/2.3.1/libraries/LittleFS/examples/FSUpload/data/

but, there was no counts.txt. So, I put one in there with a value of 100. The program just increased the count to 13. So, I modified the code so that it printed a message if the was no file found (I did the same for the "file1. txt").

void setup() {
  Serial.begin(115200);
  delay(5000);
  LittleFS.begin();
  char buff[32];
  int cnt = 1;
  File f = LittleFS.open("counts.txt", "r");
  if (f) {
    bzero(buff, 32);
    if (f.read((uint8_t *)buff, 31)) {
      sscanf(buff, "%d", &cnt);
      Serial.printf("I have been run %d times\n", cnt);
    }
    {
      Serial.println("File not found.");
    }
    f.close();
  }

  cnt++;
  sprintf(buff, "%d\n", cnt);
  f = LittleFS.open("counts.txt", "w");
  if (f) {
    f.write(buff, strlen(buff));
    f.close();
  }

  Serial.println("---------------");
  File i = LittleFS.open("file1.txt", "r");
  if (i) {
    while (i.available()) {
      Serial.write(i.read());
    }
    Serial.println("---------------");
    i.close();
  } else {
    Serial.println("No file found.");
  }
}

This was the output.

I have been run 14 times
File not found.
---------------
No file found.

So, I don't think this is working the way it seems. So, the Arduino IDE creates the following files in the system /tmp directory.

which files are actually being installed to the Pico (I'm assuming FSUpload.mklittlefs.bin, FSUpload.ino.uf2, and FSUpload.ino.elf created in the /tmp/arduino_build_xxxxx directory)? Is this assumption correct?

Frank

[earlephilhower]

You need to upload the filesystem separately using the tool and method described here: https://arduino-pico.readthedocs.io/en/latest/fs.html#uploading-files-to-the-littlefs-file-system . The files in the /tmp directory are just app build files.

[earlephilhower]

If you can't upload thru the IDE, you're not going to be able to upload through the FS uploader. Arch Linux makes it easy to configure things how you like it, but sometimes that makes it incompatible with the way other distros do it. :(

First of all, not sure if Arch supports it, but if you installed a Flatpack/Snap/etc. prepackaged version, the permissions of the app often disallow it from accessing the filesystems needed (and under Winodws it even disallows serial port access!) rendering it pretty useless. Use the tarballs from arduino.cc if that is the case and you have a good chance of things working properly. (There's also probably a way of adding permissions to the flatpack/snap/etc. but I've never tried since those kinds of "full requirements" packages seem to me like a recipe for DLL hell under Linux.)

The upload script is here:
https://github.com/earlephilhower/arduino-pico/blob/master/tools/uf2conv.py

and the (heroic) autodetect of path is here:

arduino-pico/tools/uf2conv.py

Lines 228 to 279 in 11cb82b

	def get_drives():
	drives = []
	if sys.platform == "win32":
	try:
	r = subprocess.check_output(["wmic", "PATH", "Win32_LogicalDisk",
	"get", "DeviceID,", "VolumeName,",
	"FileSystem,", "DriveType"])
	except:
	try:
	nul = open("nul:", "r")
	r = subprocess.check_output(["powershell", "-NonInteractive", "-Command",
	"Get-WmiObject -class Win32_LogicalDisk | "
	"Format-Table -Property DeviceID, DriveType, Filesystem, VolumeName"],
	stdin = nul)
	nul.close()
	except:
	print("Unable to build drive list");
	sys.exit(1)
	for line in to_str(r).split('\n'):
	words = re.split('\s+', line)
	if len(words) >= 3 and words[1] == "2" and words[2] == "FAT":
	drives.append(words[0])
	else:
	rootpath = "/run/media"
	if not os.path.isdir(rootpath):
	rootpath = "/media"
	if not os.path.isdir(rootpath):
	rootpath = "/opt/media"
	if sys.platform == "darwin":
	rootpath = "/Volumes"
	elif sys.platform == "linux":
	tmp = rootpath + "/" + os.environ["USER"]
	if os.path.isdir(tmp):
	rootpath = tmp
	for d in os.listdir(rootpath):
	drives.append(os.path.join(rootpath, d))
	if (len(drives) == 0) and (sys.platform == "linux"):
	globexpr = "/dev/disk/by-id/usb-RPI_RP2*-part1"
	rpidisk = glob.glob(globexpr)
	if len(rpidisk) > 0:
	try:
	cmd = ["udisksctl", "mount", "--block-device", os.path.realpath(rpidisk[0])]
	proc_out = subprocess.run(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
	if proc_out.returncode == 0:
	stdoutput = proc_out.stdout.decode("UTF-8")
	match = re.search(r'Mounted\s+.*\s+at\s+([^\.\r\n]*)', stdoutput)
	if match:
	drives = [match.group(1)]
	except Exception as ex:
	print("Exception executing udisksctl. Exception: {}".format(ex))
	# If it fails, no problem since it was a heroic attempt

When you hold down the BOOTSEL and plug in, is the drive auto-mounted? What path? Is that path in the above script, or elsewhere (so we could add it)?

[fapplin]

using df -h, I get:

/dev/sdd1       128M  8.0K  128M   1% /run/media/frank/RPI-RP2

I'm not sure what other info. you need.

[earlephilhower]

Reading thru the code I see:

1. /run/media exists so rootpath = /run/media
2. sys/platform==linux, and /run/media/frank exists so rootpath = /run/media/frank
3. get_drives should then return a list of all dirs in /run/media/frank which will be [/run/media/frank/RPI-RP2]

My guess is that SELinux or equivalent is blocking access by the IDE to the /run/media. That's the only way I can see it failing. You'll need to look at your selinux logs to determine this, and if so add /run/media as part of the allow for the IDE and sub-processes.

[fapplin]

OK. I'll look into it. Thanks for all your help.

[fapplin]

Just wanted you to know that I uninstalled the Arduino IDE (which was from the repo) and re-installed it from the Arduino download site - and all is well! I can do the LittleFS Data Upload and Upload right from the Arduino IDE. Lesson learned.