To work around the pesky "rf_cal[0] !=0x05" hang when booting on a chip
which doesn't have esp_init_data written to it.
It is no longer possible to do the writing of the esp_init_data_default
from within nodemcu_init(), as the SDK now hangs long before it gets
there. As such, I've had to reimplement this in our user_start_trampoline
and get it all done before the SDK has a chance to look for the init data.
It's unfortunate that we have to spend IRAM on this, but I see no better
alternative at this point.
088d2c3820