Small changes to clock calibration value will cause increasing errors
the longer the device runs. Consider the case of deep sleep, assuming
that RTC counter is used for timekeeping:
- before sleep:
time_before = rtc_counter * calibration_val
- after sleep:
time_after = (rtc_counter + sleep_count) * (calibration_val + epsilon)
where 'epsilon' is a small estimation error of 'calibration_val'.
The apparent sleep duration thus will be:
time_after - time_before = sleep_count * (calibration_val + epsilon)
+ rtc_counter * epsilon
Second term on the right hand side is the error in time difference
estimation, it is proportional to the total system runtime (rtc_counter).
To avoid this issue, this change makes RTC_SLOW_CLK calibration value
persistent across restarts. This allows the calibration value update to
be preformed, while keeping time after update same as before the update.
DPORT access protection can not work when the other CPU is stalled.
Writes to DPORT registers in esp_restart caused the program to hang due
to access protection, and the reset happened due to RTC_WDT, not SW_RST.
This change adds esp_dport_access_int_deinit function and calls it from
esp_restart once the other core is stalled.
add API to get chip info
This change adds an API to get chip info, such as chip model, enabled capabilities, size of embedded flash, silicon revision.
Hello_world example is modified to print out the information about the chip. The example is also simplified by moving all code into the main task.
Ref TW12031.
See merge request !549
Optimize configuration of base MAC address
Application developer can call APIs to configure base MAC address
instead of using menuconfig.
See merge request !744
component/esp32 : fix dualcore bug
1. When dual core cpu run access DPORT register, must do protection.
2. If access DPORT register, must use DPORT_REG_READ/DPORT_REG_WRITE and DPORT_XXX register operation macro.
See merge request !742
1. When dual core cpu run access DPORT register, must do protection.
2. If access DPORT register, must use DPORT_REG_READ/DPORT_REG_WRITE and DPORT_XXX register operation macro.
optimize scan before station connecting to AP
1. Store the information of AP(ssid, password, bssid, channel, etc)
into nvs when station connects to AP successfully. If station
connects to the same AP next time, it will scan the stored channel of the AP
first.
2. Add a parameter of channel for scanning before connecting to AP.
If the channel is set to 0, station will scan full channels. If it
is set to 1~13, station will only scan the channel.
See merge request !704
1. Store the information of AP(ssid, password, bssid, channel, etc)
into nvs when station connects to AP successfully. If station
connects to the same AP next time, it will scan the stored channel of the AP
first.
2. Add a parameter of channel for scanning before connecting to AP.
If it is set to 1~13, station will scan starting from the channel.
If the channel of AP is unknown, set it to 0.
esp32: Core dump sanity checks
Adds sanity checks when doing core dump to flash
- CRC for core dump flash partition config
- Tasks with corrupted TCBs are skipped
- Assertions to check that nothing is written beyond core dump flash partition
Ref TW11879
See merge request !686
- CRC for core dump flash partition config
- Tasks with corrupted TCBs are skipped
- Assertions to check that nothing is written beyond core dump flash partition
- RTC_CNTL_SLOWCLK_FREQ define is removed; rtc_clk_slow_freq_get_hz
function can be used instead to get an approximate RTC_SLOW_CLK
frequency
- Clock calibration is performed at startup. The value is saved and used
for timekeeping and when entering deep sleep.
- When using the 32k XTAL, startup code will wait for the oscillator to
start up. This can be possibly optimized by starting a separate task
to wait for oscillator startup, and performing clock switch in that
task.
- Fix a bug that 32k XTAL would be disabled in rtc_clk_init.
- Fix a rounding error in rtc_clk_cal, which caused systematic frequency
error.
- Fix an overflow bug which caused rtc_clk_cal to timeout early if the
slow_clk_cycles argument would exceed certain value
- Improve 32k XTAL oscillator startup time by introducing bootstrapping
code, which uses internal pullup/pulldown resistors on 32K_N/32K_P
pins to set better initial conditions for the oscillator.
Base MAC address can be stored in default manufacture-defined or customer
pre-defined place in EFUSE and other place e.g. flash or EEPROM.
If choose to use base MAC address which is stored in other place, please
call esp_base_mac_addr_set_external() before initializing WiFi/BT/Ehternet.
- Implements application tracing module which allows to send arbitrary
data to host over JTAG. This feature is useful for analyzing
program modules behavior, dumping run-time application data etc.
- Implements printf-like logging functions on top of apptrace module.
This feature is a kind of semihosted printf functionality with lower
overhead and impact on system behaviour as compared to standard printf.
Detect invalid cache access
This MR adds always-on feature which detects cache invalid access and triggers panic handler when invalid access interrupt is raised.
See merge request !660
Confusion here is that original ROM has two functions:
* SPIReadModeCnfig() - sets mode, calls enable_qio_mode/disable_qio_mode
* SPIMasterReadModeCnfig() - As above, but doesn't set QIO mode in status register
However we never want to use the ROM method to set/clear QIO mode flag, as not all flash chips work this way. Instead we
do it in flash_qio_mode.c in bootloader.
So in both cases (ROM or "patched ROM") we now call SPIMasterReadModeCnfig(), which is now named
esp_rom_spiflash_config_readmode().
Introduce soc component, add source of rtc_clk and rtc_pm libraries
This MR adds parts of the RTC library source code (initialization, clock selection functions, sleep functions). WiFi-related power management functions are kept inside the precompiled library. Most of RTC library APIs have been renamed.
Default CPU frequency option in Kconfig is set to 160MHz, pending qualification of 240MHz mode at high temperatures.
Register header files are moved into the new soc component, which will contain chip-specific header files and low-level non-RTOS-aware APIs (such as rtc_ APIs). Some of the files from ESP32 component were also moved: cpu_util.c, brownout.c, and the corresponding header files. Further refactoring of ESP32 component into more meaningful layers (chip-specific low level functions; chip-specific RTOS aware functions; framework-specific RTOS-related functions) will be done in future MRs.
See merge request !633
1) fixed SPI_read_status: added check for flash busy flag in matrix mode
2) fixed SPI_page_program: enable write before writing data to SPI FIFO
3) SPI flash ROM funcs replacement is controlled via menuconfig option
fix warnings generated by ESP_ERROR_CHECK(variable) in release builds
This uses the same pattern as “assert” in release builds to silence the
warning. At the same time, we make sure that if a statement is wrapped
into ESP_ERROR_CHECK, it is executed in release build as well.
Fixes https://github.com/espressif/esp-idf/issues/497
See merge request !641
This uses the same pattern as “assert” in release builds to silence the
warning. At the same time, we make sure that if a statement is wrapped
into ESP_ERROR_CHECK, it is executed in release build as well.
If static tx buffer is selected, WiFi tx buffers are allocated when WiFi is initialized and released
when WiFi is de-initialized. If dynamic tx buffer is selected, WiFi tx buffer is allocated when tx
data is delivered from LWIP to WiFi and released when tx data is sent out by WiFi.
The size of each static tx buffers is fixed to about 1.6KB and the size of dynamic tx buffers is
depend on the length of the data delivered from LWIP.
If PSRAM is enabled, "STATIC" should be selected to guarantee enough WiFi tx buffers.
If PSRAM is disabled, "DYNAMIC" should be selected to improve the utilization of RAM.
ULP coprocessor toolchain integration
- build system support for ULP coprocessor toolchain
- documentation for ULP coprocessor instruction set
- documentation for ULP code execution flow, loading programs, exchanging data
- example: counting pulses using ULP
See merge request !394
Reset WIFI mac when wifi start and update wifi lib
1. reset wifi mac when wifi start
2. roll back rx hung workaround for beacon timeout
3. fix amsdu ap interface wrong issue
4. fix amsdu header parse error
5. fix amsdu flag wrong issue
6. PHY: V350, fix BT rssi bug
7. RTC: V225, fix bt will be not work when wifi is reset
See merge request !606
1. reset wifi mac when wifi start
2. roll back rx hung workaround for beacon timeout
3. fix amsdu ap interface wrong issue
4. fix amsdu header parse error
5. fix amsdu flag wrong issue
6. PHY: V350, fix BT rssi bug
7. RTC: V225, fix bt will be not work when wifi is reset
1. Add low speed channels for LEDC module.
2. Improve fade object allocate mechanism.
3. Improve ledc example, add 2 low speed channels in example.
4. Remove debug code
5. Improve the register bit field name of slow clock.
add wakeup from touch sensor, and deep sleep example
- add new deep sleep wakeup mode
- change documentation to explain incompatibilities between different wakeup mode, add error checks
- add new ULP instructions necessary for ULP wakeup scenario
- fix issues with I_WR_REG, I_SLEEP, I_END instructions
- add deep sleep example, illustrating the use of timer, gpio, touch, and ULP wakeup triggers
See merge request !461
component/bt: optimize stack size of Bluetooth Tasks and make them be configurab…
Bluetooth tasks' stack size are optimized and can be configured by the CONFIG_NEWLIB_NANO_FORMAT option.
See merge request !559
Feature/add user set mac
1. Add menuconfig for user to set mac address of wifi, bt and ethernet.
2. Add the number of MAC address generated from efuse for user to choose.
3. Add MAC address derive method.
See merge request !542
This change adds esp_deep_sleep_get_wakeup_cause, which returns the
source which has caused wakeup from deep sleep.
Similar to esp_deep_sleep_get_ext1_wakeup_status, a function is added
to check touch pad wakeup status: esp_deep_sleep_get_touchpad_wakeup_status.
This function returns the touch pad which has caused wakeup.
ULP and touch FSMs in ESP32 revisions 0 and 1 do not operate correctly
if RTC_PERIPH power domain is force powered on (ESP_PD_OPTION_ON).
Both ULP and touch still work, but clock frequency of the ULP may be
incorrect and touch values may be off by considerable amount. As such,
when these wakeup modes are used, RTC_PERIPH power domain has to be set
to ESP_PD_OPTION_AUTO (or, in the current implementation,
ESP_PD_OPTION_OFF — though this will change in the future when _OFF will
actually *force* the power domain to be powered off).
Because EXT0 wakeup source requires RTC_PERIPH to be powered ON, mark
ULP and touch wakeup sources as incompatible with EXT0. Workaround for
this is to use EXT1 wakeup source instead, which offers similar or
better functions without having to keep RTC_PERIPH powered on.
1. add a macro in menuconfig for users to choose whether store phy calibration data into NVS or not.
2. rename some disable phy and rf APIs so that existing code which calls old APIS will fail to compile.
1. Add disable PHY and RF when WiFi and BT are both disabled(including call sniffer disable API).
2. Do not init PHY and RF when cpu start. Init PHY and RF when call Wifi or BT start APIs(including sniffer enable API).
3. Add a temporary lib: librtc_clk.a and will delete it when CPU frequency switching function is done.
4. Add an function to get OS tick rate.
5. Do not put the whole pp.a in iram0, only put lmac.o, ieee80211_misc.o, ets_time.o and wdev.o in iram0.
If using WIFI_INIT_CONFIG_DEFAULT, error message will point out lack
of WiFi. Otherwise linker errors on WiFi symbols should help give a
clue as to what is broken.
Piggy-backs on changes in !420, ref github #230#237
esp32 core dump to flash
1. menuconfig option to select where to store core dump: flash, uart or disable
2. Saving of core dump to flash
3. Partition table definitions files with core dump partition
4. Python scripts to support core dump generation from GDB command line
See merge request !341
Deep sleep stub may call ets_update_cpu_frequency, which has been moved from ROM to IRAM.
Restore the ROM version in the linker script, call it ets_update_cpu_frequency_rom, use it in the deep sleep stub.
1) PS is fixed up to allow GDB backtrace to work properly
2) MR!341 discussion: in core dump module: esp_panicPutXXX was replaced by ets_printf.
3) MR!341 discussion: core dump flash magic number was changed.
4) MR!341 discussion: SPI flash access API was redesigned to allow flexible critical section management.
5) test app for core dump feature was added
6) fixed base64 file reading issues on Windows platform
7) now raw bin core file is deleted upon core loader failure by epscoredump.py
Complimentary changes:
1) Partition table definitions files with core dump partition
2) Special sub-type for core dump partition
3) Special version of spi_flash_xxx
4) espcoredump.py is script to get core dump from flash and print useful info
5) FreeRTOS API was extended to get tasks snapshots
add wpa2 set id api and modify null data tx description
1. wpa2: add wpa2 set id api
2. low rate: modify null data tx description
See merge request !402
ethernet: support flow control
(1) Only fullduplex mode support flow ctrl .
(2) Fix reboot exception which caused by not-reset EMAC hardware (such as DMA) when reset CPU.
See merge request !392
SDMMC peripheral driver, SD protocol driver, FATFS library, VFS integration
This MR contains:
- SDMMC host peripheral driver
- SD protocol driver in sdmmc component (can be extended to support MMC/eMMC and SPI based hosts)
- ChaN's FATFS library v0.12b
- VFS integration
- FAT access via VFS is thread-safe (unless same file is read/written/unlinked/renamed from different tasks)
- Support for POSIX directory-related functions in VFS (and in vfs_fatfs.c)
- unit test for the above
- Example
- API documentation
Will be done in other MRs:
- Support for spi_flash IO driver for FatFs
- SPI host driver and support for SPI mode commands in sdmmc component
- MMC/eMMC support in sdmmc component
- Support for slightly higher 53/26.6MHz clocks (currently I'm using 20MHz for DS and 40MHz for HS, instead of 25MHz/50MHz per standard), and arbitrary low clocks (e.g. 4MHz).
See merge request !353
Enable bootloader entropy source for RNG
Enables an entropy source when bootloader starts up, which both seeds the RNG for use before WiFi/BT stack is enabled and provides an adequate RNG for secure boot & flash encryption key generation.
A prerequisite was enabling 80MHz operation, so the CPU is now set to 80MHz as soon as second stage bootloader starts running.
See merge request !363
1. Update wifi lib which contains ampdu and other optimizations
2. Add throughput code debug code
3. Other misc modification about throughput optimization
2. update example comments and other minor changes
3. rename API: i2c_cmd_link_create/i2c_cmd_link_delete (+4 squashed commits)
Squashed commits:
[2e0ac3e] 1. coding style: add one space after condition key words.
2. modify i2c.h, use gpio_num_t instead of int, improve comments of return values
3. add i2c index in index.rst
4. add readme for i2c example
[4991d92] update i2c.doc
[88b672e] driver: i2c
1. add mux and spin lock to run in a thread-safe way.
2. modify example code
[4eb15fe] driver: i2c code
1. add i2c master code
2. add i2c slave code
3. add i2c example code
4. add DRAM_ATTR for I2C array
1. add sigma-delta code and example.
2. add gpio output signal in io matrix.
Squashed commits:
[a25e7d4] minor changes for doc
[6a03a1e] minor changes on comments and doc.
[97dd9e4] Add doc.
update index.rst
change example index
This change allows setting pin configuration for EXT1 wakeup depending on the state of RTC_PERIPH power domain:
- if peripherals are enabled (due to another wakeup mode, or due to esp_deep_sleep_pd_config call), we can keep internal pullups/pulldowns enabled
- if peripherals are disabled, pullups and pulldowns need to be disabled as well
Also add comments about the purpose of registers being configured.
This adds the following APIs to enable various wakeup sources:
- esp_deep_sleep_enable_timer_wakeup
- esp_deep_sleep_enable_ulp_wakeup
- esp_deep_sleep_enable_ext0_wakeup
- esp_deep_sleep_enable_ext1_wakeup
And an API to start deep sleep:
- esp_deep_sleep_start
1. TW8657, WIFI send the whole packet to smartconfig;
2. modify API annotation of smartconfig and sniffer;
3. export smartconfig APIs to programming guide;
Flash encryption support
Flash encryption support in build system, tooling
To come in future MR:
* On-device key generation on first boot (for production devices), need to finalise testing of bootloader entropy seeding.
* spi_flash_encrypted_write to support non-32-byte block writes (at least optionally.)
* I think a lot of the bootloader_support component can possibly be rolled into "spiflash" and other components, to use a common API.
See merge request !240
Add dynamic interrupt allocation mechanism
This adds:
- Dynamic allocation of interrupts. Pass it the features of the interrupt you want, it'll set you up with an int.
- Shared interrupts. Enables multiple peripheral drivers to use the same interrupt.
- Marking what interrupts are fully executable from IRAM; if an int isn't marked like that it will get disabled once flash cache gets disabled.
Also:
- Modifies driver to be in line with these changes
See merge request !254
- ROM function uart_tx_wait_idle may have a bug which causes the function to return before the final character is fully transmitted.
This replaces uart_tx_wait_idle declaration with a static inline definition which fixes the issue.
- Also replaces the use of uart_tx_flush with uart_tx_wait_idle in esp_restart, to remove garbage in console output on restart.
- rtc_printf is temporary replaced with a no-op, pending a new release of librtc.a. Current release assumes that UART0 is used for output,
and switches UART0 baud rate while doing frequency changes and printing some log output. This doesn’t work if a different UART is used for output.
feature(rtc_module):add rtc module
1. add rtc io control API (pull,output and input)
2. add touch pad API (touch pad read and interrupt)
3. add adc1 API (the max width is 12 Bits and support attenuation)
4. add hall sensor API (support hall sensor read )
5. add dac API (the width is 8 Bits)
bugfix(gpio):gpio32 and gpio33 can not output and input
the gpio32 and gpio33 is initialize by librtc.a,and gpio_config not initialize the gpio as
digital gpio.they can not output and input,when users use gpio32 or gpio33.And there are some problems
about others driver ,when they use gpio32 or gpio33 as matrix.
* App access functions are all flash encryption-aware
* Documentation for flash encryption
* Partition read/write is flash aware
* New encrypted write function
Feature/btdm bluedroid
This branch contain the bluedroid host code.
Currently, Only GAP/GATT SERVER/GATT CLIENT release to users.
Actually, the content of the codes is further more than GAP/GATT and etc.
In this release version, users only need to concern about the APIs which are in "api/include/".
Now, suggestions in comment have been resolved are following:
1. The APIs use callback function. Ivan , Jeroen and me have discussed it. Currently the code will not be changed.
2. The APIs use OPEN/CLOSE. I have ask Ivan, besides bluedroid do this, we will keep the name.
3. Coding style. I have run format.sh to handle the style. And some spell error have been fixed.
4. APIs doxygen. I have clean the warning by doxygen. But bt.rst is still need to be completed.
5. Other comment without resolved face to face that I have to add response in the comment and fix them in the code
6. Fix some incorrect things. See the git log for details.
This 1st version of bluedroid release still have lots of things to do. But it can be done after this merge.
1. Compelete the BLUFI(Bluetooth config wifi connection) documents, security, application protocol and other.
2. Add SPP-LIKE profile.
3. Do more examples codes to cover most of the APIs.
4. Test and fix bug.
Another thing：
1. Do the document of APIs.(xml->bt.rst->html)
(I will do this before merge as Ivan's suggestion)
This is already done. Besides, the union type in doxygen have something error. Ivan will fix it.
See merge request !239
1. fix tw8911 sleep in scan leads to auth frame malloc fail.
2. fix tw8913 pm state transfer wrong leads to wdt.
3. make some comments for modem sleep and wpa2 enterprise.
4. removd duplicated debug option ESP_THREAD_SAFE_DEBUG
Bugfix mbedtls sha384 clone()
mbedtls_sha512_clone() on a SHA-384 hash caused incorrect digest
Also adds additional mbedtls unit tests into the unit tests project (including one for this bug).
See merge request !252
SHA acceleration integrated to mbedTLS incl. TLS sessions
Uses hardware SHA acceleration where available, fails over to software where not available.
Ref TW7112
See merge request !232
spi_flash_erase_range: Allow for 32KB blocks not 64KB blocks
SPI flash hardware sends 52h command, which is a 32KB erase.
There is a matching bug in the ROM SPIEraseArea code, unless
flashchip->block_size is modified first.
See merge request !249
driver: PCNT
1. add PCNT module in periph_ctrl.c/.h
2. add description of PCNT status in pcnt_struct.h
3. add PCNT driver code
4. add PCNT example code.
See merge request !229
SPI flash hardware sends 52h command, which is a 32KB erase.
There is a matching bug in the ROM SPIEraseArea code, unless
flashchip->block_size is modified first.
SHA hardware allows each of SHA1, SHA256, SHA384&SHA512 to calculate digests
concurrently.
Currently incompatible with AES acceleration due to a hardware reset problem.
Ref TW7111.
hwcryto bignum support for RSA operations
Supporting RSA with hardware bignum directives.
Configurable via menuconfig to enable/disable, and to choose between busywaiting and interrupt driven completion.
May still be some performance tweaks possible.
TW7111
See merge request !92
esp32/make: add detailed return error code for wifi APIs
1. Add detailed return error code for wifi APIs
2. Add description about error code in esp_wifi.h
3. Modify esp_wifi_reg_rxcb to esp_wifi_internal_reg_rxcb
4. Modify esp_wifi_set_sta_ip to esp_wifi_internal_set_sta_ip
5. Mark system_init as deprecated API
See merge request !187
1. Add detailed return error code for wifi APIs
2. Add description about error code in esp_wifi.h
3. Modify esp_wifi_reg_rxcb to esp_wifi_internal_reg_rxcb
4. Modify esp_wifi_set_sta_ip to esp_wifi_internal_set_sta_ip
5. Mark system_init as deprecated API
Deep sleep: Any source named rtc_wake_stub* is linked as RTC wake stub code
Also move esp_deepsleep.h documentation out to docs/deep-sleep-stub.rst
See merge request !142
Add cross-core int to accelerate task being awoken from another CPU.
This adds a per-CPU interrupt that can be used to poke the CPU to go do something. In this case all that is implemented is a request to yield the current task, used in case a CPU unblocks a task that runs on another CPU. This gets rid of the limitation that inter-CPU communication using queues, muxes etc can take up to a FreeRTOS tick to happen.
Specs!
Sending an in in a queue of length 1 (essentially a semaphore) as quickly as possible (just a small delay in the sender, to make sure the receiver task gets swapped out) for 10 seconds. Number indicates the amount of ints transferred
Old code:
CPU0->CPU0: 42986
CPU0->CPU1,: 2999
New code:
CPU0->CPU0: 42868
CPU0->CPU1: 62073
See merge request !155
- spaces->tabs in tasks.c
- update vfs_uart.c to use per-UART locks
- add license to vfs_uart.c
- allocate separate streams for stdout, stdin, stderr, so that they can be independently reassigned
- fix build system test failure
Feature/wdts
This adds two watchdogs to esp-idf:
- An interrupt watchdog. Kicks in if the FreeRTOS timer interupt on either the PRO_CPU or (when configured) the APP CPU isn't called for a configurable time. Panics, displaying which CPU caused the problem and the registers that may lead to the offending code.
- A task watchdog. A task has to feed it every once in a while. If not, it will print the name of the offending tasks, as well as the tasks currently running on both CPUs, and optionally panic.
Also adds a panic reason to the panic call, as well as fixes the panic code a bit.
See merge request !148
The customers need to get information about AP that associated with ESP32 station,
these information includes RSSI, channel number etc, so add this new API
1. Modify sta to station in comments
2. Modify esp_wifi_get_ap_num to esp_wifi_scan_get_ap_num
3. Modify esp_wifi_get_ap_list to esp_wifi_scan_get_ap_records
1. Modify comments for esp_wifi_internal_tx
2. Fix delay time error in esp32_tx_flow_ctrl which is found in code review,
modify _wait_delay init value from 0 to 1
Some small fixes
- Kill unused uxReturn in task.c, https://github.com/espressif/esp-idf/issues/48
- Line end conversion in gpio.c
- Move heap_alloc_caps.h so components can also use it
See merge request !135
esp32: Bootloader wake deep sleep stub
App can contain a stub program resident in RTC fast memory. Bootloader
will load the stub on initial boot. If the device wakes from deep sleep,
the stub is run immediately (before any other data is loaded, etc.)
To implement a custom wake stub, implement a function in your program:
```
void RTC_IRAM_ATTR esp_wake_deep_sleep(void)
{
esp_default_wake_deep_sleep();
// other wake logic
}
```
... and it will replace the default implementation.
See merge request !78
We reserve 4KB Slow RTC memory to save RF calibation result and BT NVS data.
If not all these Slow RTC momory Blocks are used, we will open the other parts.
App can contain a stub program resident in RTC fast memory. Bootloader
will load the stub on initial boot. If the device wakes from deep sleep,
the stub is run immediately (before any other data is loaded, etc.)
To implement a custom wake stub, implement a function in your program:
```
void RTC_IRAM_ATTR esp_wake_deep_sleep(void)
{
esp_default_wake_deep_sleep();
// other wake logic
}
```
... and it will replace the default implementation.
While this may reduce esp_wifi.h file readability for people who don't have a "go to definition" function in their editors, this is needed to decouple esp_wifi and esp_event headers, and possibly other headers which may use wifi types in the future.
This change separates definitions in esp_event.h and functions in event.c into several parts:
- event structure definitions (esp_event.h)
- default implementations of event handlers (event_default_handlers.c)
- default implementation of event loop (event_loop.c, esp_event_loop.h)
Purpose of this change is to allow applications choose their own poison:
- full control of event loop at the expense of more bootstrap code
- pre-defined event task firing event callbacks, but less code in app_main.c
This change removes implicit WiFi/BT initialization from startup code.
"main" task is started once essential part of startup code is complete.
This task calls application-provided "int main(void)" function, which can call WiFi/BT init functions if necessary.
