Hi,
I am trying to upload a file to ESP32S3 using FatFS. I have the data folder and a small .png in it. I am using arduino-portable and have a local partitions.csv on the same level as .ino. It looks like this:

# Name,   Type, SubType, Offset,  Size, Flags
nvs,      data, nvs,     0x9000,  0x5000,
otadata,  data, ota,     0xe000,  0x2000,
app0,     app,  ota_0,   0x10000, 0x640000,
app1,     app,  ota_1,   0x650000,0x640000,
storage,  data, fat,     0xc90000,0x360000,
coredump, data, coredump,0xFF0000,0x10000,


In the VM menu I have selected Partition Scheme: Custom and FileSystem Upload Tool: FileFS.
I build the project and then I click on Publish Server Data Files in VM menu.

In the VS console I get this (had to add spaces here and there to fix formatting):

ESP32FSUpload.exe
## recipe.wwwfiles.upload.pattern
"c:\program files (x86)\microsoft visual studio\2019\enterprise\common7\ide\extensions\fpbblalf.uhm/ESP32FSUpload.exe" -serial.port=COM6 -build.path="C:\Users\User\AppData\Local\Temp\VMBuilds\ESP32S3_4848S040_Clock3 \esp32_esp32s3\Debug" -target_platform="esp32" -runtime.tools.mkspiffs.path="notTheToolYoureLookingFor" -board.name="ESP32S3 Dev Module" -upload.verbose=True -upload.resetmethod={upload.resetmethod} -upload.speed=921600 -platform.path="C:\Arduino\ESP32S3_Clock3\arduino-portable\packages \esp32\hardware\esp32\3.1.1" -project.name="ESP32S3_4848S040_Clock3.ino" -project.path="C:\Arduino\ESP32S3_Clock3\ESP32S3_4848S040_Clock3" -tools.esptool.cmd="{tools.esptool.cmd}" -tools.esptool.cmd.windows="{tools.esptool.cmd.windows}" -runtime.tools.esptool.path="{runtime.tools.esptool.path}" -compiler.path="C:\Arduino\ESP32S3_Clock3\arduino-portable\packages\esp32\tools \esp-x32\2405/bin/" -build.spiffs_start="{build.spiffs_start}" -build.spiffs_end="{build.spiffs_end}" -build.spiffs_pagesize="{build.spiffs_pagesize}" -build.spiffs_blocksize="{build.spiffs_blocksize}" -build.partitions="" -network.password={network.password} -network.auth_upload={network.auth_upload} -network.port=3232 -upload.tool=esptool_py -tools.esptool_py.cmd="esptool.exe" -tools.esptool_py.cmd.windows="esptool.exe" -runtime.tools.esptool_py.path="C:\Arduino\ESP32S3_Clock3\arduino-portable\pack ages\esp32\tools\esptool_py\4.9.dev3" -build.flash_mode=dio -build.flash_freq=80m
ERROR: FATFS partitions not defined for ESP32S3 Dev Module

I also checked 

c:\Users\User\AppData\Local\Temp\VMBuilds\ESP32S3_4848S040_Clock3\esp32_esp 
32s3\Debug\partitions.csv 

and it has the same content as my local partitions.csv

That didn't seems to help, if I pick partition scheme "16MB Flash (3MB APP, 9.9MB FATFS) the parameter changes to -build.partitions="default" and I get the same error.

I was then playing around with boards.txt, trying to add my own partition scheme in:

c:\Arduino\ESP32S3_Clock3\arduino-portable\packages\esp32\hardware\esp32\3.1.1\ tools\partitions

and then use it in:
c:\Arduino\ESP32S3_Clock3\arduino-portable\packages\esp32\hardware\esp32\3.1.1\ boards.txt 

And I noticed it has no effect on what's shown in VM partitions menu. 
I then tried to modify boards.txt in my arduino installation:

c:\Users\User\AppData\Local\Arduino15\packages\esp32\hardware\esp32\2.0.17\ boards.txt

and the menu changed (even though the project is using arduino-portable). 

When I remove my local partitions.csv I get this (with 16MB Flash (3MB APP, 9.9MB FATFS) still selected in menu):

Program too big. The size is 1467800 bytes (of a 1310720 byte maximum)

Looks like it's picking up the default esp32c3.upload.maximum_size=1310720 (from c:\Arduino\ESP32S3_Clock3\arduino-portable\packages\esp32\hardware\esp32\3.1.1\ boards.txt)

Reviewing the Program Size issue mentioned, the entry in boards.txt is overridden if the partitions.csv can be read from the build folder, which will be the same one you have in your project\partitions.csv (as it is copied in the pre-build hooks to the build folder).

It is done this way to ensure a custom partition setup gives the right warning on program size, without needing a custom board.txt entry.

Does this now align with the custom paritions.csv you have in use?

The initial issue with the error of not being able to identify the partitions is fixed in the latest release (25.0120.0) which can be downloaded from the top of the below board:
https://www.visualmicro.com/forums/YaBB.pl?board=VS_ARDUINO_EXT_RELEASES

Simon@Visual Micro wrote on Jan 20^th, 2025 at 5:38pm:


I am now getting:
ERROR: FATFS partition size could not be found

Using the same local partitions.csv as in my original post and "Custom" partition scheme from the menu.

EDIT:
if I change the partition name to
ffat,     data, fat,     0xc90000,0x360000,

the upload works. I thought the name could be anything, I saw it called "storage" it some examples.