Espressif Systems ESP - Page 134

Chapter 4. Software framework
4.9.1 My application does not really need the watchdog timer, can I disable it?
There are two types of watchdog in ESP-IDF: task watchdog and interrupt watchdog. You can disable these two types
of watchdog in menucon󰝘g. For more details, please refer to Watchdogs.
4.9.2 What are the dierences between RTOS SDK and Non-OS SDK?
The main di󰝗erences are as follows:
Non-OS SDK
• Non-OS SDK uses timers and callbacks as the main way to perform various functions - nested
events and functions triggered by certain conditions. Non-OS SDK uses the espconn network
interface; users need to develop their software according to the usage rules of the espconn interface.
RTOS SDK
• FreeRTOS SDK is based on FreeRTOS , a multi-tasking OS. You can use the standard FreeRTOS
interfaces to realize resource management, recycling operations, execution delay, inter-task mes-
saging and synchronization, and other task-oriented process design approaches. For the speci󰝘cs
of interface methods, please refer to the o󰝚cial website of FreeRTOS or the book USING THE
FreeRTOS REAL TIME KERNEL-A Practical Guide.
• The network operation interface in RTOS SDK is the standard lwIP API. RTOS SDK provides
a package which enables BSD Socket API interface. Users can directly use the socket API to
develop software applications; and port other applications from other platforms using socket API
to ESP8266, e󰝗ectively reducing the learning and development cost arising from platform switch.
• RTOS SDK introduces cJSON library whose functions make it easier to parse JSON packets.
• RTOS is compatible with Non-OS SDK in Wi-Fi interfaces, SmartCon󰝘g interfaces, Sni󰝗er related
interfaces, system interfaces, timer interface, FOTA interfaces and peripheral driver interfaces, but
does not support the AT implementation.
4.9.3 Why does the log output ets_main.c when ESP8266 starts?
If ESP8266 prints ets_main.c when it starts, it indicates there are no programs that can be operated.
Please check the binary 󰝘le and burn address if you encounter this issue.
4.9.4 Why do I get compile errors when using IRAM_ATTR in Non-OS SDK?
The default function attribute is IRAM_ATTR in Non-OS SDK. Therefore, if you want the function
to reside in IRAM, please leave out the ICACHE_FLASH_ATTR attribution in the function de󰝘ni-
tion/declaration.
4.9.5 Where is main function in ESP8266?
• ESP8266 SDK does not provide main function. Main function is stored in 󰝘rst-stage bootloader in ROM,
which is used to load second-stage bootloader. The entry function of the second-stage bootloader is ets_main.
After startup, the user_init in the user application will be loaded to lead the user to the program.
Espressif Systems 117
Submit Document Feedback
Release master