PyPortal Titano not honoring RunMode.UF2 flag on_next_reset

[bcr]

CircuitPython version

Adafruit CircuitPython 8.2.1 on 2023-07-25; Adafruit PyPortal Titano with samd51j20

Code/REPL

>>> import microcontroller
>>> microcontroller.on_next_reset(microcontroller.RunMode.UF2)
>>> microcontroller.reset()

Behavior

Reboots to normal running CircuitPython

Description

When I run the provided code, it just goes back to normal user mode.

Additional information

If I use the older RunMode.BOOTLOADER it mounts the PORTALBOOT drive which is what I want.

I think the problem is here https://github.com/adafruit/circuitpython/blob/main/ports/atmel-samd/common-hal/microcontroller/__init__.c#L66

My suggested change is:

diff --git a/ports/atmel-samd/common-hal/microcontroller/__init__.c b/ports/atmel-samd/common-hal/microcontroller/__init__.c
index d1c02b360..054d7ee7f 100644
--- a/ports/atmel-samd/common-hal/microcontroller/__init__.c
+++ b/ports/atmel-samd/common-hal/microcontroller/__init__.c
@@ -63,7 +63,7 @@ void common_hal_mcu_enable_interrupts(void) {
 }
 
 void common_hal_mcu_on_next_reset(mcu_runmode_t runmode) {
-    if (runmode == RUNMODE_BOOTLOADER) {
+    if ((runmode == RUNMODE_BOOTLOADER) || (runmode == RUNMODE_UF2)) {
         if (!bootloader_available()) {
             mp_raise_ValueError(translate("Cannot reset into bootloader because no bootloader is present"));
         }

But this suggestion could be uninformed, dangerous, or just plain wrong. I don't know if there are some SAMD that have both a bootloader and a UF2 mode for instance.

[bcr]

I was able to build and install the firmware.uf2 and this patch acts as I expect on the PyPortal Titano.

Adafruit CircuitPython 8.2.0-68-ge7e6fc844 on 2023-08-06; Adafruit PyPortal Titano with samd51j20
>>> import microcontroller
>>> microcontroller.on_next_reset(microcontroller.RunMode.UF2)
>>> microcontroller.reset()

[jepler]

Good catch. Can you prepare a pull request? It looks like all ports should probably be reviewed but if your PR is just for one port that's fine.

[bcr]

OK, my 124 checks seem to have passed.

[bcr]

The following probably need review, I did not find any other places. I can make these changes if you like but I have no testing environment.

circuitpython/ports/cxd56/common-hal/microcontroller/__init__.c

Line 74 in 6b36bf5

if (runmode == RUNMODE_BOOTLOADER) {

circuitpython/ports/mimxrt10xx/common-hal/microcontroller/__init__.c

Line 70 in 272a2dc

if (runmode == RUNMODE_BOOTLOADER) {

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

Line 81 in 272a2dc

if (runmode == RUNMODE_BOOTLOADER) {

[bcr]

@jepler When will this ship? I think this was merged to main but not to the 8.2.x branch.

[tannewt]

It is already available in 9.x alphas. They are pretty stable so I'd suggest using them.