can marlin share an SD card via WIFI on skr-2 board (1 reply)

I have an skr2 with an esp32u (BTT) add on wifi module. Got it connected as a simple serial setup, thats fine. But what I would really like to be able to do is send files to the esp32 and have it write them to a shared SD card. From studying the pinouts, it really seems like I should be able to setup and spi connection to my sd card. Ideally that would be the one in my LCD, but I could live with it being the on board one too. So is this even possible?

here is what has led me to believe it might be:

from the adv config file:

/**
 * Native ESP32 board with WiFi or add-on ESP32 WiFi-101 module
 */
//#define WIFISUPPORT         // Marlin embedded WiFi management. Not needed for simple WiFi serial port.
//#define ESP3D_WIFISUPPORT   // ESP3D Library WiFi management (https://github.com/luc-github/ESP3DLib)

this confuses me slightly....seems like "...or add on ESP21 WIFI module" is my case? But maybe thats for and esp32 mb running esp32 wifi add on?

I waanted to enable that because it brings some variables into play:

#if ENABLED(WIFISUPPORT)
  //
  // WIFI
  //

  /**
   *                      -------
   *            GND | 9  |       | 8 | 3.3V
   *  (ESP-CS) PB12 | 10 |       | 7 | PB15 (ESP-MOSI)
   *           3.3V | 11 |       | 6 | PB14 (ESP-MISO)
   * (ESP-IO0) PB10 | 12 |       | 5 | PB13 (ESP-CLK)
   * (ESP-IO4) PB11 | 13 |       | 4 | --
   *             -- | 14 |       | 3 | 3.3V (ESP-EN)
   *  (ESP-RX)  PD8 | 15 |       | 2 | --
   *  (ESP-TX)  PD9 | 16 |       | 1 | PC14 (ESP-RST)
   *                      -------
   *                       WIFI
   */
  #define ESP_WIFI_MODULE_COM                  3  // Must also set either SERIAL_PORT or SERIAL_PORT_2 to this
  #define ESP_WIFI_MODULE_BAUDRATE      BAUDRATE  // Must use same BAUDRATE as SERIAL_PORT & SERIAL_PORT_2
  #define ESP_WIFI_MODULE_RESET_PIN         PC14
  #define ESP_WIFI_MODULE_GPIO0_PIN         PB10
  #define ESP_WIFI_MODULE_GPIO4_PIN         PB11
#endif

Unfortunately, I cant get by the errors it throws when I turn wifiSupport on(working on that tonight).
Now, esp3d allows for an sd card connection and requires the pin assignments shown in the attached image. The second image in the pinout of my wifi board.

So the CS, SCK, MISO & MOSI pins seem pretty straight forward. But I cant figure out the sd detect pin or the shared disk flag(if there is one).
Of the remaining pins, I know its not RST, TX or RX. That leaves IO0(PB10 @ STM32) and IO4(PB11 @STM32) as candidates for the detect pin.

I have tried both of those options, as well as "none"...no success yet. Conceptually, it seems like I need to do something in marlin to connect the "detect pin" to the esp32, but I haven't the slightest clue how do make that happen. Was kinda hoping that wifiSupport might do it for me....

Any help would be appreciated, thanks so much!