rtos

#01 : NuttX 是什麼 ?? NuttX Real-Time Operating System NuttX is a real-time operating system (RTOS) with an emphasis on standards compliance and small footprint. Scalable from 8-bit to 32-bit microcontroller environments, the primary governing standards in NuttX are Posix and ANSI standards. Additional standard APIs from Unix and other common RTOS's (such as VxWorks) are adopted for functionality not available under these standards, or for functionality that is not appropriate for deeply-embedded environments (such as fork()). NuttX was first released in 2007 by Gregory Nutt under the permissive

Suppose there is two task running TASK_A and TASK_B. While TASK_A is running an interrupt occurred and a context switch to TASK_B is needed. While inside ISR, TASK_B should not be directly jumped since it is still in ISR and have'nt returned yet (for eg: RETI is not executed). If normally returned from ISR it will as usual go back to the TASK_A's last program counter. So the RTOS has to get out of the ISR and as soon as it is out of the ISR it has to do a context switch to TASK_B. Instead of going back to TASK_A how does a RTOS get back control as soon as it exit ISR. In case of switching from

There are many different RTOS available for microcontrollers. I am specifically looking for RTOS that support the ARM Cortex M processors. Also, I am not interested in closed source solutions. Attempting to compare the relative merits of each RTOS from websites and mailing lists seems pretty difficult as they mostly seem to have equivalent features and do the same thing. The real differences become apparently only after trying to use each RTOS for some tasks. I know this is somewhat subjective question and probably hard to answer - but there must be many people out there who have actually