KERNEL

WHAT'S NEW

FreeRTOS website now available in Simplified Chinese

Search and browse content in your preferred language. See the blog post.

New FreeRTOS Long Term Support version now available.

Receive security patches and critical bug fixes on FreeRTOS libraries for two years. See the blog post.

FreeRTOS Extended Maintenance Program (EMP) registration now open.

Providing security patches and critical bug fixes on FreeRTOS Long Term Support (LTS) versions for up to 10 additional years. See the blog post.

FreeRTOS-Plus-TCP v3.0.0 released:

We've added comprehensive unit tests and penetration and protocol testing. See the blog post.

Featured FreeRTOS IoT Integrations:

Introducing three featured integrations for more secure IoT applications. See the blog post.

The AVR Context
[RTOS Implementation Building Blocks]

A context switch requires the entire execution context to be saved. On the AVR microcontroller the context consists of:

32 general purpose processor registers. The gcc development tools assume register R1 is set to zero.
Status register. The value of the status register affects instruction execution, and must be be preserved across context switches.
Program counter. Upon resumption, a task must continue execution from the instruction that was about to be executed immediately prior to its suspension.
The two stack pointer registers.