microcontroller.reset() to bootloader on esp32-s2

[FoamyGuy]

Running these commands in REPL my device is rebooting into standard mode coming up as a CIRCUITPY drive.

import microcontroller
microcontroller.on_next_reset(microcontroller.RunMode.BOOTLOADER)
microcontroller.reset()

Tested on:

Adafruit CircuitPython 6.1.0-beta.2-182-g1b7fbaf31 on 2020-12-26; Adafruit MagTag with ESP32S2

and

Adafruit CircuitPython 6.1.0-beta.2-30-g6cced4940 on 2020-12-13; FeatherS2 with ESP32S2

I have previously followed the process to have UF2 combo bootloader on my devices.

[microdev1]

microcontroller.RunMode.BOOTLOADER isn't implemented on the esp32s2.

circuitpython/ports/esp32s2/common-hal/microcontroller/__init__.c

Lines 70 to 73 in 1b7fbaf

	void common_hal_mcu_on_next_reset(mcu_runmode_t runmode) {
	if(runmode == RUNMODE_SAFE_MODE)
	safe_mode_on_next_reset(PROGRAMMATIC_SAFE_MODE);
	}

I don't think it is possible to enter DFU (first-stage) bootloader on esp32s2 from software.
I tried to get reset to UF2 bootloader working but I am facing a strange issue #3813.

[ladyada]

there is some way to enter the DFU bootloader from usercode because arduino does it...
@me-no-dev do you have any hints we could use to implement? :)

[me-no-dev]

@ladyada here is the shutdown handler that does the reboot into the proper mode: https://github.com/espressif/arduino-esp32/blob/idf-release/v4.2/cores/esp32/esp32-hal-tinyusb.c#L458-L479

it is registered here: https://github.com/espressif/arduino-esp32/blob/idf-release/v4.2/cores/esp32/esp32-hal-tinyusb.c#L531

Let me know if this does not help :)

[microdev1]

Thanks! @me-no-dev, this works... the changes are in my update-run-mode branch. :)

[dhalbert]

Thanks! @me-no-dev, this works... the changes are in my update-run-mode branch. :)

@microdev1 Could you make your changes into a PR?

[microdev1]

@microdev1 Could you make your changes into a PR?

This is stuck due to idf@v4.2. In my implementation, the function calls used to achieve this are part of idf@v4.3.

[ThomasAtBBTF]

I just want to point out, that I am very interested that this feature will work in the not to distance future,