Quality RTOS & Embedded Software

Featured FreeRTOS IoT Integrations:
Extended Maintenance Plan (EMP):
Delta Over-the-Air Updates:
December 2021 Releases:
FreeRTOS LTS libraries:


[FreeRTOS+TCP API Reference]


Note: this hook needs to be defined only when ipconfigDHCP_REGISTER_HOSTNAME is set to 1 in the FreeRTOSIPConfig.h file.

const char * pcApplicationHostnameHook( void );

eApplicationHostnameHook is an application defined hook (or callback) function that is called by the FreeRTOS+TCP stack when an IP-address is requested from a DHCP server. This allows the device to register its hostname with the DHCP server.

Callback functions are implemented by the application writer, but called by the TCP/IP stack. The prototype of the callback function must exactly match the prototype above (including the function name). The code in an application hook should not call FreeRTOS+TCP API's that are blocking. That could easily lead to a dead-lock.

When an application hook executes, it borrows the task priority and the stack of the IP-task. Therefore, we recommend that you keep application hooks short--it may want to wakeup some application task which will do further processing.

Return value:

A NULL terminated hostname which the device can send to register with the DHCP server. The maximum length of the hostname can be 32 characters.

Copyright (C) Amazon Web Services, Inc. or its affiliates. All rights reserved.