planck_rev6 &bootloader doesn't work

[orbekk]

The &bootloader key doesn't work with my planck_rev6. The keyboard appears to restart but boots back into ZMK when I press the &bootloader key.

It looks like qmj writes a magic value that triggers the planck bootloader. Perhaps ZMK needs to do this.

[urob]

+1 &bootloader doesn't work on my planck_rev6 either

[urob]

Quick summary of @petejohanson's comments on this on discord:

ZMK uses the Zephyr function sys_reboot (which in turn calls the device specific function sys_arch_reboot) for rebooting and resetting. The issue is that Zephyr does not currently have a stm32-specific implementation of sys_arch_reboot, causing it to fall back to a baseline version that does not support magic codes.

tl;dr: To fix the &bootloader for Planck (and other stm32 devices), one would need to add a stm32-specific implementation of sys_arch_reboot to Zephyr itself.