Reboot to DFU?

There's nothing built in to Espruino though I'm afraid, but if it works maybe we should add it!

Well, I proposed that previously but so far your argument was that it is dangerous - someone with access to console can remotely update your device so something physical (holding button) to enter DFU is safer.

Some watches uses also value 1 in GPREGRET to trigger DFU so in my custom builds I have one liner

--- a/targets/nrf5x_dfu/main.c
+++ b/targets/nrf5x_dfu/main.c
@@ -149,18 +153,19 @@ bool nrf_dfu_enter_check(void) {
 bool dfu_enter_check(void) {
 [#endif](https://forum.espruino.com/sear­ch/?q=%23endif)
   bool dfu_start;
+  if (NRF_POWER->GPREGRET == 1) { NRF_POWER->GPREGRET=0; return true; }
 [#ifdef](https://forum.espruino.com/sear­ch/?q=%23ifdef) BTN1_PININDEX
   dfu_start = get_btn1_state();
 [#else](https://forum.espruino.com/searc­h/?q=%23else)

but I agree that it is somewhat dangerous.
With that one liner in bootloader you enter DFU by poke32(0x4000051c,1), with softdevice enabled it automatically reboots (into DFU)