Copying FAT FS to a computer

[nzagorec]

Hi,

I piped all ESP_LOGx to a file on ffat partition and I'd like to access it on my computer by dumping the whole FS to it and mounting it as an image.

I tried downloading FS onto my computer using esptools' read_flash command. The received file is indeed mountable and I can see the file/folder structure but contents of these files are not correct.

Here's how my partitions.csv file looks like:
ffat, data, fat, 0x2C0000, 1M,

write_flash command:
esptool.py --chip esp32 --port /dev/cu.usbserial-230 --baud 921600 --after no_reset write_flash -z 0x2C1000 filesystem.img

read_flash command:
esptool.py --chip esp32 --port /dev/cu.usbserial-230 --baud 230400 --after no_reset read_flash 0x2C0000 0x100000 filesystem_dump.img

*for some reason when I use faster baud rates than 230400 the read_flash command fails with "A fatal error occurred: Invalid head of packet (0x27): Possible serial noise or corruption."

Do you see something obvously wrong with my procedure?

[magicmicros]

All looks good to me.
The serial error IS probably what it says - noise on the line. Not all TTL dongles (if that's what you use) are created similarly. Some are sensitive with the voltage levels and might occasionally give errors. Odd that you don't have the problem with writing, tough.
If you can mount and see the folder structure, but not the files (you don't say WHAT is wrong with the files), it suggest they're written wrong.
What about the folder structure, did you write that in advance or did the ESP32 create it?
Can you properly read back file contents on the ESP32?

[nzagorec]

Sorry, I didn't provide enough details.

First I create FS with mk_espfat, mount it on my computer and add files to it (e.g. one of the files is a JSON-structured text file). Then I upload the .img file to ESP32. The content of these files is properly read by the ESP32. Furthermore, ESP creates more files on the filesystem and manipulates them. Then, I do read_flash as I mentioned earlier and what I see is:

• dumped .img file is exactly the same size as the original one
• after I mount it all files are there with correct filenames
• HOWEVER, when I hexdump the files their content is different (essentially garbage)

A bit of context: what I'm trying to do here is pipe all the log to a .log file on the filesystem and then collect it after e.g. 24 h. I can print the log to UART but I was hoping I could just dump the whole FS to my computer and open it in Notepad instead.

[magicmicros]

Sounds like the actual writing of the logs are the problem.
Have you tried writing some simple text files to the FS, to see if that works?