Why is software interrupt used in FreeRTOS

I am working with FreeRTOS for ARM7_LPC2106_GCC. I saw in the startup file a call to vPortYieldProcessor in the SWI interrupt handler. Where is SWI used in FreeRTOS?

Why is software interrupt used in FreeRTOS

Did you try searching the source directory for SWI?

Why is software interrupt used in FreeRTOS

SWI is called each time taskYIELD() is called, which can be from inside an API function or just called directly by a task. Regards.