The former correction factors were determined by measuring the resulting clocks without a device connected to the bus.
However, when testing the changes for low CPU clock frequencies, it was figured out that the clocks not only depend on configured register values
_i2c_hw[dev].regs->scl_low_period.period
_i2c_hw[dev].regs->scl_high_period.period
but also on the bus capacity. Obviously, the register values are not absolute times in APB clock cycles, but rather times that start as soon as the corresponding level is reached. In this case, the higher the bus capacity, the longer the period would be.
This means that the clock speed cannot be precisely controlled via the correction factors anyway. For this reason, and because the I2C implementation in ESP-IDF also does not use correction factors, they were removed.
With the change from using archive files to using object files in PR #14754, the module `esp_wifi_enterprise` was no longer compilable. The reason for this was that the file `bignum.c` was present in two different vendor sub-directories and created two identical object files, which then led to a symbol conflict when linking. This commit removes one of these identical files. The one that is used in all `esp_wifi` variants is kept, the one that is only used in `esp_wifi_enterprise` is dropped.
The IRAM is much faster, while the IROM is much slower and can only be accessed via a cache, which is also sometimes disabled, e.g. by the WiFi module or when writing to the flash. Therefore, time-critical code as well as code that has to work even when the cache is disabled must be placed in the IRAM.
Checksumming flash is not supported on xtensa platform:
Warn : not implemented yet
make: *** [.../RIOT/examples/saul/../../Makefile.include:796: flash] Error 1
https://github.com/espressif/openocd-esp32 is needed.
Example config (when compiled from source):
export OPENOCD="~/esp/openocd-esp32/src/openocd -s ~/esp/openocd-esp32/tcl"
If esp_idf_heap is not used, implement calloc through a custom wrapper
function on top of malloc to add overflow detection, which is not
present in the newlib forks with xtensa support yet.
The RTT overflow callback is not available on all RTT implementations.
This means it is either a no-op or `rtt_set_overflow_cb()` is a no-op
or it will overwrite the alarm set with `rtt_set_alarm()`.
This adds a feature to indicate that proper overflow reporting is available.
Some periph_rtt implementations do not provide `rtt_set_counter()`. This
adds `periph_rtt_set_counter` as feature to allow testing for its
availability. The feature is provided at CPU level if periph_rtt is
provided by the board for all CPUs implementing `rtt_set_counter()`.
Some periph_rtt implementations do not provide `rtt_set_counter()`. This
adds `periph_rtt_set_counter` as feature to allow testing for its
availability. The feature is provided at CPU level if periph_rtt is
provided by the board for all CPUs implementing `rtt_set_counter()`.
If there is an event to be handled by _esp_eth_isr(), don't
overwrite it if a new packet has been received.
In my testing, all SYSTEM_EVENT_ETH_CONNECTED events except the first
are immediately followed by at least one SYSTEM_EVENT_ETH_RX_DONE event.
This causes the SYSTEM_EVENT_ETH_CONNECTED to not get handled, and the
IP stack will not be notified of the new link state.
Protect the other events by dropping the packet instead. If an earlier
unhandled SYSTEM_EVENT_ETH_RX_DONE event exists, overwrite it with the
newer packet.
I only saw this happen with lwIP and not with GNRC - I am not sure why.
But it still is a race waiting to happen. The nice long term solution
is probably to have a queue of unhandled events, allowing them all to
be processed once there is time.
