If needed these parameters can be added back and made functional one at a
time. It's better to explicitly not support them than to silently allow
but ignore them.
Python defines warnings as belonging to categories, where category is a
warning type (descending from exception type). This is useful, as e.g.
allows to disable warnings selectively and provide user-defined warning
types. So, implement this in MicroPython, except that categories are
represented just with strings. However, enough hooks are left to implement
categories differently per-port (e.g. as types), without need to patch each
and every usage.
With clock bypass enabled the attached SD card is clocked at the maximum
48MHz. But some SD cards are unreliable at these rates. Although it's
nice to have high speed transfers it's more important that the transfers
are reliable for all cards. So disable this clock bypass option.
This way the UART REPL does not need the MicroPython heap and exists
outside the MicroPython runtime, allowing characters to still be received
during a soft reset.
Auto-detection of the crystal frequency is convenient and allows for a
single binary for many different boards. But it can be unreliable in
certain situations so in production, for a given board, it's recommended to
configure the correct fixed frequency.
Stig Bjørlykke
Ayke van Laethem
Damien George
Paul Sokolovsky