is it possible to update via SD card using PSRAM as temp storage?

[tschak909]

Hey guys,

Our FujiNet project (https://github.com/FujiNetWIFI/fujinet-platformio/) uses an ESP32-WROVER-E with 16mb of available flash, and 8MB of PSRAM.

Is it possible to update the ESP32 via SD card, using PSRAM as temp storage? Our firmware has the potential to grow larger, and doing the typical route via OTA is not as appealing to us, as it takes a substantial amount of our flash storage away from us for future development.

-Thom

[MicroController]

Update from an SD card should be possible in theory. You'd have to include SD card and FAT drivers into a custom bootloader (not the standard IDF drivers though, since they depend on FreeRTOS running), or into a small factory app.

PSRAM is of little use in this case. An application cannot overwrite itself while running no matter where the update data comes from.